Ophthalmic Exam

Introduction

Overview

• Vision testing:
  • Visual acuity
  • Peripheral vision
  • Color vision
• Office exam:
  • Examination of the external eye
  • Conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy
  • Sclera Sclera The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. Eye: Anatomy
  • Iris
  • Pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities
  • Extraocular movements
  • Ophthalmoscopic exam of the fundus Fundus The superior portion of the body of the stomach above the level of the cardiac notch. Stomach: Anatomy
• Detailed exam by slit lamp:
  • Cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy
  • Anterior chamber Anterior chamber The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. Eye: Anatomy
  • Lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy
  • Dilated exam of the retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy

Eye examination recommendations

Recommended frequency of eye exams is not standard, but in general:

• Children:
  • At birth
  • At 6–12 months
  • At 3 years of age
  • Early teens
  • Annually, if vision correction is needed
  • As needed for symptoms or injuries
• Adults:
  • Once in the 20s and 30s
  • Every 2 years after 40–50 years of age including screening Screening Preoperative Care for glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma
  • Annually, if vision correction is needed
  • Annually for individuals with diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus
  • As needed for symptoms or injuries

A dilated exam helps diagnose:

• Diabetic retinopathy Diabetic retinopathy Disease of the retina as a complication of diabetes mellitus. It is characterized by the progressive microvascular complications, such as aneurysm, intraretinal edema, and intraocular pathologic neovascularization. Chronic Diabetic Complications
• Hypertensive retinopathy Retinopathy Degenerative changes to the retina due to hypertension. Alport Syndrome
• Macular degeneration Macular degeneration Age-related macular degeneration (AMD) is visual impairment due to changes in the macula, the area responsible for high-acuity vision. It is marked by central vision loss with peripheral vision relatively spared. Risk factors include advanced age, smoking, family history, and cardiovascular disease. Macular Degeneration
• Retinal detachment Retinal detachment Retinal detachment is the separation of the neurosensory retina from the retinal pigmented epithelium and choroid. Rhegmatogenous retinal detachment, the most common type, stems from a break in the retina, allowing fluid to accumulate in the subretinal space. Retinal Detachment

History

• Wellness exam or visual complaints
• History of glasses or contact lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy use
• Family history Family History Adult Health Maintenance:
  • Glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma
  • Color blindness Blindness The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of eye diseases; optic nerve diseases; optic chiasm diseases; or brain diseases affecting the visual pathways or occipital lobe. Retinopathy of Prematurity
  • Other eye diseases
• Chronic medical conditions
• Surgical history
• Medications

Anatomy

The eye and its appendages are situated in the orbit. The eyeball is spheroidal and attached to the extraocular muscles.

• The front of the eye:
  • Cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy: the transparent anterior ⅙th of the outer eyeball
  • Sclera Sclera The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. Eye: Anatomy:
    • “White part” of the eye
    • Fibrous Fibrous Fibrocystic Change, protective, outer layer
    • Made up mainly of collagen Collagen A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of skin; connective tissue; and the organic substance of bones (bone and bones) and teeth (tooth). Connective Tissue: Histology and some crucial elastic Elastic Connective Tissue: Histology fibers
  • Limbus Limbus An annular transitional zone, approximately 1 mm wide, between the cornea and the bulbar conjunctiva and sclera. It is highly vascular and is involved in the metabolism of the cornea. Eye: Anatomy: the junction of the cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy and sclera Sclera The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. Eye: Anatomy
  • Conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy: the transparent mucus membrane that attaches to the limbus Limbus An annular transitional zone, approximately 1 mm wide, between the cornea and the bulbar conjunctiva and sclera. It is highly vascular and is involved in the metabolism of the cornea. Eye: Anatomy
  • Iris:
    • The “colored part” of the eye
    • Connected to the anterior part of the ciliary body Ciliary body A ring of tissue extending from the scleral spur to the ora serrata of the retina. It consists of the uveal portion and the epithelial portion. The ciliary muscle is in the uveal portion and the ciliary processes are in the epithelial portion. Eye: Anatomy
    • Covers the top of the lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy and acts as a shutter for the eye
  • Ciliary body Ciliary body A ring of tissue extending from the scleral spur to the ora serrata of the retina. It consists of the uveal portion and the epithelial portion. The ciliary muscle is in the uveal portion and the ciliary processes are in the epithelial portion. Eye: Anatomy: holds the lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy in place
• Uvea Uvea The pigmented vascular coat of the eyeball, consisting of the choroid; ciliary body; and iris, which are continuous with each other. Eye: Anatomy (middle vascular coat of the eye):
  • Anterior uvea Uvea The pigmented vascular coat of the eyeball, consisting of the choroid; ciliary body; and iris, which are continuous with each other. Eye: Anatomy: iris and ciliary body Ciliary body A ring of tissue extending from the scleral spur to the ora serrata of the retina. It consists of the uveal portion and the epithelial portion. The ciliary muscle is in the uveal portion and the ciliary processes are in the epithelial portion. Eye: Anatomy
  • Choroid Choroid The thin, highly vascular membrane covering most of the posterior of the eye between the retina and sclera. Eye: Anatomy: Posterior portion of the uvea Uvea The pigmented vascular coat of the eyeball, consisting of the choroid; ciliary body; and iris, which are continuous with each other. Eye: Anatomy
    • Contains blood vessels that provide nutrients to the eye
    • Located between the retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy and sclera Sclera The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. Eye: Anatomy
    • Extends to the optic nerve Optic nerve The 2nd cranial nerve which conveys visual information from the retina to the brain. The nerve carries the axons of the retinal ganglion cells which sort at the optic chiasm and continue via the optic tracts to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the superior colliculi and the suprachiasmatic nuclei. Though known as the second cranial nerve, it is considered part of the central nervous system. The 12 Cranial Nerves: Overview and Functions posteriorly
• The back of the eye:
  • Retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy:
    • The nerve coat of the eye
    • Responsible for the perception Perception The process by which the nature and meaning of sensory stimuli are recognized and interpreted. Psychiatric Assessment of vision
    • Contains several photoreceptor cells
    • Connected to the optic nerve Optic nerve The 2nd cranial nerve which conveys visual information from the retina to the brain. The nerve carries the axons of the retinal ganglion cells which sort at the optic chiasm and continue via the optic tracts to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the superior colliculi and the suprachiasmatic nuclei. Though known as the second cranial nerve, it is considered part of the central nervous system. The 12 Cranial Nerves: Overview and Functions
  • Macula Macula An oval area in the retina, 3 to 5 mm in diameter, usually located temporal to the posterior pole of the eye and slightly below the level of the optic disk. It is characterized by the presence of a yellow pigment diffusely permeating the inner layers, contains the fovea centralis in its center, and provides the best phototropic visual acuity. It is devoid of retinal blood vessels, except in its periphery, and receives nourishment from the choriocapillaris of the choroid. Eye: Anatomy (area in the center of the retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy):
    • Responsible for clearly seeing objects in detail
    • Required for activities such as driving and reading
  • Fovea Fovea An area approximately 1. 5 millimeters in diameter within the macula lutea where the retina thins out greatly because of the oblique shifting of all layers except the pigment epithelium layer. It includes the sloping walls of the fovea (clivus) and contains a few rods in its periphery. In its center (foveola) are the cones most adapted to yield high visual acuity, each cone being connected to only one ganglion cell. Eye: Anatomy centralis: a small depression in the macula Macula An oval area in the retina, 3 to 5 mm in diameter, usually located temporal to the posterior pole of the eye and slightly below the level of the optic disk. It is characterized by the presence of a yellow pigment diffusely permeating the inner layers, contains the fovea centralis in its center, and provides the best phototropic visual acuity. It is devoid of retinal blood vessels, except in its periphery, and receives nourishment from the choriocapillaris of the choroid. Eye: Anatomy where vision is the sharpest
• Extraocular muscles:
  • 6 muscles that control eye movements
  • 4 rectus muscles:
    • Superior
    • Inferior
    • Lateral
    • Medial
  • 2 oblique muscles:
    • Superior
    • Inferior

Equipment for examination

• Snellen chart or handheld pocket card for testing visual acuity
• Ishihara chart for testing color blindness Blindness The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of eye diseases; optic nerve diseases; optic chiasm diseases; or brain diseases affecting the visual pathways or occipital lobe. Retinopathy of Prematurity
• Penlight for examining the pupils
• Ophthalmoscope for examining the retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy/ fundus Fundus The superior portion of the body of the stomach above the level of the cardiac notch. Stomach: Anatomy
• Special equipment used primarily by eye specialists or emergency physicians Physicians Individuals licensed to practice medicine. Clinician–Patient Relationship:
  • Slit lamp to examine the cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy
  • Tonometer to measure intraocular pressure
  • Eye drops for pupillary dilation:
    • Phenylephrine Phenylephrine An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent. Sympathomimetic Drugs
    • Atropine Atropine An alkaloid, originally from atropa belladonna, but found in other plants, mainly solanaceae. Hyoscyamine is the 3(s)-endo isomer of atropine. Anticholinergic Drugs
    • Tropicamide Tropicamide One of the muscarinic antagonists with pharmacologic action similar to atropine and used mainly as an ophthalmic parasympatholytic or mydriatic. Anticholinergic Drugs
    • Cyclopentolate Cyclopentolate A parasympatholytic anticholinergic used solely to obtain mydriasis or cycloplegia. Anticholinergic Drugs
  • Fluorescein Fluorescein A phthalic indicator dye that appears yellow-green in normal tear film and bright green in a more alkaline medium such as the aqueous humor. Pseudomonas and UV lamp to detect corneal abrasions Abrasions Corneal Abrasions, Erosion, and Ulcers
  • Amsler grid
  • Perimeter-testing machines

Vision Testing

Visual acuity testing

Snellen chart:

• Shows a series of 11 lines of block letters on a white background, each progressively diminishing in size:
  • The smallest row that can be read accurately indicates the visual acuity in that specific eye.
  • Line 8 is 20/20 vision, indicating a person with normal visual acuity can read this line accurately from 20 feet away (6.1 m).
• The “Tumbling E” eye chart can detect nearsightedness Nearsightedness Refractive Errors in young children or in individuals who cannot read.
• Procedure:
  • The subject sits or stands 20 feet (6.1 m) from the Snellen chart.
  • The subject is asked to cover an eye, read the chart with each eye separately, and then with both eyes Both Eyes Refractive Errors. Visual acuity for each is recorded as a fraction (e.g., 20/30).
  • Counting fingers test: tested if the subject is unable to read the top line even from 3 feet (0.91 m). The subject is asked to count the number of fingers held up by the examiner. Results are recorded as CF–1, 2, or 3 based on the number of fingers accurately visualized and counted. 
  • Hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy movement (HM): tested if the subject is unable to count fingers; recorded as HM positive or HM negative
  • Light-perception test: for subjects unable to count fingers or appreciate hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy movements; recorded as PL positive or PL negative 

Near-vision chart:

• Used to test near vision at a distance of 35 cm (14 inches)
• Jaeger eye chart (with 10 lines of progressively smaller print) is commonly used:
  • Text sizes increasing from 0.37–2.5 mm
  • Acuity is recorded at the smallest line that can be accurately read by the subject.

Clinical relevance:

• Refractive disorders can be treated with refractive devices (glasses or contact lenses):
  • Myopia Myopia Refractive Errors: nearsightedness Nearsightedness Refractive Errors
  • Hyperopia Hyperopia Refractive Errors: farsightedness Farsightedness Refractive Errors
  • Astigmatism Astigmatism Unequal curvature of the refractive surfaces of the eye. Thus a point source of light cannot be brought to a point focus on the retina but is spread over a more or less diffuse area. This results from the radius of curvature in one plane being longer or shorter than the radius at right angles to it. . Refractive Errors: Blurred vision Blurred Vision Retinal Detachment due to a warped corneal surface causes light rays entering the eye along different planes to be focused unevenly.
• Presbyopia Presbyopia The normal decreasing elasticity of the crystalline lens that leads to loss of accommodation. Refractive Errors:
  • Nonrefractive error Error Refers to any act of commission (doing something wrong) or omission (failing to do something right) that exposes patients to potentially hazardous situations. Disclosure of Information in older adults
  • Affects visual acuity due to loss of normal lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy accommodation Accommodation Refractive Errors

Visual field Visual Field The Visual Pathway and Related Disorders testing

The field of vision is the total area in which objects can be visualized while looking straight ahead; it includes central vision and peripheral vision.

• Exam for peripheral vision = confrontation test
  • Procedure:
    • The examiner sits facing the subject at the same head level but at a distance of about 60 cm (2 feet).
    • The individual is asked to cover their left eye Left Eye Refractive Errors with the palm of their hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy and is told to look straight into the examiner’s left eye Left Eye Refractive Errors.
    • The examiner closes their right eye Right Eye Refractive Errors and moves their hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy in from the periphery toward the common line of vision.
    • The examiner announces that they can see hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy movement when it enters their field of vision.
    • The movement of the hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy is repeated in various parts of the field of vision, that is above, below, to the right, to the left.
    • The process is repeated for the other eye.
  • Results: The subject should confirm the movement of the hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy in their field of vision, which is compared with that of the examiner (assuming it is normal).
• Other tests used by eye specialists:
  • Perimetry:
    • Manual or automated perimeter machines are used to examine and quantify the visual field Visual Field The Visual Pathway and Related Disorders of individuals using targets of various sizes and colors.
    • Clinical relevance: Decreased peripheral vision may be due to damage to the optic nerve Optic nerve The 2nd cranial nerve which conveys visual information from the retina to the brain. The nerve carries the axons of the retinal ganglion cells which sort at the optic chiasm and continue via the optic tracts to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the superior colliculi and the suprachiasmatic nuclei. Though known as the second cranial nerve, it is considered part of the central nervous system. The 12 Cranial Nerves: Overview and Functions, retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy, or areas of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification that process vision (e.g., after a stroke).
  • Amsler grid:
    • A test for central vision loss Central Vision Loss Macular Degeneration occurring due to macular degeneration Macular degeneration Age-related macular degeneration (AMD) is visual impairment due to changes in the macula, the area responsible for high-acuity vision. It is marked by central vision loss with peripheral vision relatively spared. Risk factors include advanced age, smoking, family history, and cardiovascular disease. Macular Degeneration
    • Horizontal and vertical lines in a grid with a single dot in the center
    • 1 eye is tested at a time from 30 cm away.
    • The subject is asked to fix their vision on the central dot and describe any patterns they see in their vision.
    • Amsler grid is used to detect defects in the central 20 degrees of the visual field Visual Field The Visual Pathway and Related Disorders.
• Clinical relevance
  • Testing of visual fields helps diagnose:
    • Optic nerve Optic nerve The 2nd cranial nerve which conveys visual information from the retina to the brain. The nerve carries the axons of the retinal ganglion cells which sort at the optic chiasm and continue via the optic tracts to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the superior colliculi and the suprachiasmatic nuclei. Though known as the second cranial nerve, it is considered part of the central nervous system. The 12 Cranial Nerves: Overview and Functions damage
    • Glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma
    • Hemianopsia
    • Cataracts
  • Amsler grid can be used to evaluate an individual’s central visual field Visual Field The Visual Pathway and Related Disorders, particularly for macular degeneration Macular degeneration Age-related macular degeneration (AMD) is visual impairment due to changes in the macula, the area responsible for high-acuity vision. It is marked by central vision loss with peripheral vision relatively spared. Risk factors include advanced age, smoking, family history, and cardiovascular disease. Macular Degeneration.

Color vision

• Delineates red/green and total color perception Perception The process by which the nature and meaning of sensory stimuli are recognized and interpreted. Psychiatric Assessment deficiency
• Can be performed in the office to diagnose color blindness Blindness The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of eye diseases; optic nerve diseases; optic chiasm diseases; or brain diseases affecting the visual pathways or occipital lobe. Retinopathy of Prematurity
• Ishihara color test: 14 colorful, numbered plates for mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast screening Screening Preoperative Care and classroom use

Eye Examination

General exam of the face

• Head posture:
  • May be abnormal in individuals with squinting
  • The head may be turned in the direction of action of the paralyzed muscle (e.g., stroke).
  • With ptosis Ptosis Cranial Nerve Palsies, the chin Chin The anatomical frontal portion of the mandible, also known as the mentum, that contains the line of fusion of the two separate halves of the mandible (symphysis menti). This line of fusion divides inferiorly to enclose a triangular area called the mental protuberance. On each side, inferior to the second premolar tooth, is the mental foramen for the passage of blood vessels and a nerve. Melasma is elevated to uncover the pupillary area.
• Forehead Forehead The part of the face above the eyes. Melasma:
  • Complete loss of wrinkling on 1 side of the forehead Forehead The part of the face above the eyes. Melasma is seen in individuals with lower motor neuron Lower Motor Neuron Motor Neuron Lesions facial palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies (e.g., Bell’s palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies).
  • Facial asymmetry Asymmetry Examination of the Upper Limbs may also be noted in individuals with sequelae of stroke, but only the lower half of the face is affected (not the forehead Forehead The part of the face above the eyes. Melasma).
  • Mnemonic:
    • B as in Bell’s palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies: Both upper and lower face are affected.
    • S as in Stroke: Only the Smile is affected.

External eye

Preliminary examination for any gross anomalies in the eye and the surrounding structures is conducted in diffuse light. The clinically relevant findings are:

Eyebrow: 

• Level of the eyebrows may be changed in individuals with ptosis Ptosis Cranial Nerve Palsies.
• Madarosis Madarosis Blepharitis (absence of hair in the lateral ⅓rd of the eyebrows) is seen in:
  • Leprosy Leprosy Leprosy, also known as Hansen’s disease, is a chronic bacterial infection caused by Mycobacterium leprae complex bacteria. Symptoms primarily affect the skin and peripheral nerves, resulting in cutaneous manifestations (e.g., hypopigmented macules) and neurologic manifestations (e.g., loss of sensation). Leprosy
  • Hypothyroidism Hypothyroidism Hypothyroidism is a condition characterized by a deficiency of thyroid hormones. Iodine deficiency is the most common cause worldwide, but Hashimoto’s disease (autoimmune thyroiditis) is the leading cause in non-iodine-deficient regions. Hypothyroidism

Eyelids Eyelids Each of the upper and lower folds of skin which cover the eye when closed. Blepharitis:

• Position:
  • Normally, the lower eyelid covers the corneal limbus Limbus An annular transitional zone, approximately 1 mm wide, between the cornea and the bulbar conjunctiva and sclera. It is highly vascular and is involved in the metabolism of the cornea. Eye: Anatomy and the upper eyelid covers 2 mm of the cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy with the eyes open.
  • In cases of ptosis Ptosis Cranial Nerve Palsies, the eyelid covers more than one-sixth of the cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy.
  • Upper limbus Limbus An annular transitional zone, approximately 1 mm wide, between the cornea and the bulbar conjunctiva and sclera. It is highly vascular and is involved in the metabolism of the cornea. Eye: Anatomy may be seen due to lid retraction in:
    • Thyrotoxicosis Thyrotoxicosis A hypermetabolic syndrome caused by excess thyroid hormones which may come from endogenous or exogenous sources. The endogenous source of hormone may be thyroid hyperplasia; thyroid neoplasms; or hormone-producing extrathyroidal tissue. Thyrotoxicosis is characterized by nervousness; tachycardia; fatigue; weight loss; heat intolerance; and excessive sweating. Thyrotoxicosis and Hyperthyroidism
    • Sympathetic overactivity
• Movement:
  • Normally, the upper lid follows the eyeball with downward movement.
  • With thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy ophthalmopathy, the upper-lid movement lags behind the downward gaze.
  • Lagophthalmos Lagophthalmos Leprosy (inability to close the eyes completely) seen with:
    • Facial nerve palsy Facial Nerve Palsy Lyme Disease
    • Extreme proptosis Proptosis Retinoblastoma
  • Normal blinking rate is 12–16 per minute:
    • Increased with local irritation
    • Reduced with 7th nerve palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies
• Lid margin:
  • Entropion Entropion The turning inward (inversion) of the edge of the eyelid, with the tarsal cartilage turned inward toward the eyeball. Sjögren’s Syndrome: inward turning of the lid margin
  • Ectropion Ectropion The turning outward (eversion) of the edge of the eyelid, resulting in the exposure of the palpebral conjunctiva. Sjögren’s Syndrome:
    • Outward turning of the lid margin
    • The common causes include trachoma Trachoma A chronic infection of the conjunctiva and cornea caused by Chlamydia trachomatis. Chlamydial Infections, blepharitis Blepharitis Blepharitis is an ocular condition characterized by eyelid inflammation. Anterior blepharitis involves the eyelid skin and eyelashes, while the posterior type affects the meibomian glands. Often, these conditions overlap. Blepharitis, stye Stye A hordeolum is an acute infection affecting the meibomian, Zeiss, or Moll glands of the eyelid. Stasis of the gland secretions predisposes to bacterial infection. Staphylococcus aureus is the most common pathogen. Hordeolum (Stye), and lid trauma.
  • Distichiasis: an abnormal extra row of eyelashes
  • Madarosis Madarosis Blepharitis (absence of eyelashes) can be seen in:
    • Chronic blepharitis Blepharitis Blepharitis is an ocular condition characterized by eyelid inflammation. Anterior blepharitis involves the eyelid skin and eyelashes, while the posterior type affects the meibomian glands. Often, these conditions overlap. Blepharitis
    • Leprosy Leprosy Leprosy, also known as Hansen’s disease, is a chronic bacterial infection caused by Mycobacterium leprae complex bacteria. Symptoms primarily affect the skin and peripheral nerves, resulting in cutaneous manifestations (e.g., hypopigmented macules) and neurologic manifestations (e.g., loss of sensation). Leprosy
    • Hypothyroidism Hypothyroidism Hypothyroidism is a condition characterized by a deficiency of thyroid hormones. Iodine deficiency is the most common cause worldwide, but Hashimoto’s disease (autoimmune thyroiditis) is the leading cause in non-iodine-deficient regions. Hypothyroidism
  • Swelling Swelling Inflammation at lid margin may be due to:
    • Hordeolum Hordeolum A hordeolum is an acute infection affecting the meibomian, Zeiss, or Moll glands of the eyelid. Stasis of the gland secretions predisposes to bacterial infection. Staphylococcus aureus is the most common pathogen. Hordeolum (Stye) ( stye Stye A hordeolum is an acute infection affecting the meibomian, Zeiss, or Moll glands of the eyelid. Stasis of the gland secretions predisposes to bacterial infection. Staphylococcus aureus is the most common pathogen. Hordeolum (Stye))
    • Papilloma Papilloma A circumscribed benign epithelial tumor projecting from the surrounding surface; more precisely, a benign epithelial neoplasm consisting of villous or arborescent outgrowths of fibrovascular stroma covered by neoplastic cells. Cowden Syndrome
    • Marginal chalazion Chalazion A chalazion is one of the most common inflammatory lesions of the eyelid. It is caused by obstruction of the Meibomian or Zeis glands, leading to granulomatous inflammation and resulting in a firm, rubbery, slow-growing nodule that is typically non-tender. Chalazion
  • Ankyloblepharon (horizontally narrow palpebral fissure Fissure A crack or split that extends into the dermis Generalized and Localized Rashes) seen at angles of the eye after:
    • Adhesions of the lids after ulcerative blepharitis Blepharitis Blepharitis is an ocular condition characterized by eyelid inflammation. Anterior blepharitis involves the eyelid skin and eyelashes, while the posterior type affects the meibomian glands. Often, these conditions overlap. Blepharitis
    • Adhesions of the lids after burns Burns A burn is a type of injury to the skin and deeper tissues caused by exposure to heat, electricity, chemicals, friction, or radiation. Burns are classified according to their depth as superficial (1st-degree), partial-thickness (2nd-degree), full-thickness (3rd-degree), and 4th-degree burns. Burns
  • Blepharophimosis (narrow palpebral fissure Fissure A crack or split that extends into the dermis Generalized and Localized Rashes): usually a congenital Congenital Chorioretinitis anomaly
  • Vertically narrow palpebral fissure Fissure A crack or split that extends into the dermis Generalized and Localized Rashes seen in:
    • Inflammatory conditions of the conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy
    • Inflammatory conditions of the cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy and uvea Uvea The pigmented vascular coat of the eyeball, consisting of the choroid; ciliary body; and iris, which are continuous with each other. Eye: Anatomy
    • Ptosis Ptosis Cranial Nerve Palsies
    • Enophthalmos Enophthalmos Recession of the eyeball into the orbit. Marfan Syndrome and anophthalmos
    • Atrophic bulbi
  • Vertically wide palpebral fissure Fissure A crack or split that extends into the dermis Generalized and Localized Rashes seen in:
    • Proptosis Proptosis Retinoblastoma
    • Retraction of the upper lid
    • Facial nerve palsy Facial Nerve Palsy Lyme Disease
• Lacrimal apparatus:
  • Inspection Inspection Dermatologic Examination of lacrimal sac Lacrimal Sac Dacryocystitis area for:
    • Redness Redness Inflammation
    • Swelling Swelling Inflammation
    • Fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula
  • Inspection Inspection Dermatologic Examination of the lacrimal puncta for defects such as:
    • Eversion Eversion Chronic Apophyseal Injury
    • Stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS)
    • Absence
    • Discharge
  • Regurgitation Regurgitation Gastroesophageal Reflux Disease (GERD) test for dacryocystitis Dacryocystitis Dacryocystitis is inflammation of the lacrimal sac due to nasolacrimal duct obstruction and the subsequent stasis of tears. The condition can have an acute or chronic onset. Acute dacryocystitis presents within hours or days with redness, swelling, tenderness, and excessive tearing. Dacryocystitis: Press over the lacrimal sac Lacrimal Sac Dacryocystitis area just medial to the medial canthus and observe for regurgitation Regurgitation Gastroesophageal Reflux Disease (GERD) of any discharge from the puncta.

Conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy

Examination:

• Bulbar part of the conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy can be examined by retracting the eyelid with the fingers.
• Lower palpebral conjunctiva Palpebral Conjunctiva Blepharitis: Pull down the lower eyelid while the subject looks upward.
• Upper palpebral conjunctiva Palpebral Conjunctiva Blepharitis: Retract the upper eyelid gently with the fingers.

Clinical relevance:

• Discoloration:
  • Primary acquired melanosis Melanosis Disorders of increased melanin pigmentation that develop without preceding inflammatory disease. Primary Biliary Cholangitis: Unilateral, painless, brown macule Macule Nonpalpable lesion < 1 cm in diameter Generalized and Localized Rashes can transform to malignant melanoma Melanoma Melanoma is a malignant tumor arising from melanocytes, the melanin-producing cells of the epidermis. These tumors are most common in fair-skinned individuals with a history of excessive sun exposure and sunburns. Melanoma.
  • Pale conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy: seen with anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types
  • Bright red patches Patches Vitiligo: indicative of subconjunctival hemorrhage
• Congestion:
  • Superficial: conjunctivitis Conjunctivitis Conjunctivitis is a common inflammation of the bulbar and/or palpebral conjunctiva. It can be classified into infectious (mostly viral) and noninfectious conjunctivitis, which includes allergic causes. Patients commonly present with red eyes, increased tearing, burning, foreign body sensation, and photophobia. Conjunctivitis
  • Deep: iridocyclitis Iridocyclitis Acute or chronic inflammation of the iris and ciliary body characterized by exudates into the anterior chamber, discoloration of the iris, and constricted, sluggish pupil. Symptoms include radiating pain, photophobia, lacrimation, and interference with vision. Relapsing Fever or keratitis Keratitis Inflammation of the cornea. Herpes Simplex Virus 1 and 2
  • Mixed: glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma
• Edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema:
  • Inflammatory conditions
  • Infection
  • Allergic reactions Allergic Reactions Type I hypersensitivity reaction against plasma proteins in donor blood Transfusion Reactions
• Follicles:
  • Grayish-white raised areas ( aggregation Aggregation The attachment of platelets to one another. This clumping together can be induced by a number of agents (e.g., thrombin; collagen) and is part of the mechanism leading to the formation of a thrombus. Coagulation Studies of lymphocytes Lymphocytes Lymphocytes are heterogeneous WBCs involved in immune response. Lymphocytes develop from the bone marrow, starting from hematopoietic stem cells (HSCs) and progressing to common lymphoid progenitors (CLPs). B and T lymphocytes and natural killer (NK) cells arise from the lineage. Lymphocytes: Histology) seen in:
    • Trachoma Trachoma A chronic infection of the conjunctiva and cornea caused by Chlamydia trachomatis. Chlamydial Infections
    • Acute follicular conjunctivitis Acute Follicular Conjunctivitis Conjunctivitis
• Papillae Papillae Lips and Tongue: Anatomy (see photo):
  • Red, raised areas with flat tops
  • Seen in:
    • Trachoma Trachoma A chronic infection of the conjunctiva and cornea caused by Chlamydia trachomatis. Chlamydial Infections
    • Allergic conjunctivitis Allergic Conjunctivitis Conjunctivitis
    • Giant papillary conjunctivitis Conjunctivitis Conjunctivitis is a common inflammation of the bulbar and/or palpebral conjunctiva. It can be classified into infectious (mostly viral) and noninfectious conjunctivitis, which includes allergic causes. Patients commonly present with red eyes, increased tearing, burning, foreign body sensation, and photophobia. Conjunctivitis (GPC)
• Concretions:
  • Yellowish-white raised areas varying in size
  • Represent thickened mucous and dead epithelial cells in the glands of Henle
  • Seen in:
    • Trachoma Trachoma A chronic infection of the conjunctiva and cornea caused by Chlamydia trachomatis. Chlamydial Infections
    • Conjunctival degeneration
    • Can be idiopathic Idiopathic Dermatomyositis
• Pinguecula:
  • Yellowish, triangular, avascular Avascular Corneal Abrasions, Erosion, and Ulcers nodule Nodule Chalazion resembling a fat drop
  • Fatty/proteinaceous deposits on the conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy (does not involve the cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy)
  • Develops on the bulbar conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy in response to:
    • UV light UV light That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-uv or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-uv or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants. Bullous Pemphigoid and Pemphigus Vulgaris exposure
    • Wind irritation
    • Dust irritation
  • May progress to pterygium
  • May or may not obscure field of vision
• Pterygium (see photo):
  • Yellowish, triangular, vascular nodule Nodule Chalazion resembling a fat drop
  • Fatty/proteinaceous deposits on the conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy (involves the cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy)
  • Develops on the bulbar conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy in response to:
    • UV light UV light That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-uv or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-uv or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants. Bullous Pemphigoid and Pemphigus Vulgaris exposure
    • Wind irritation
    • Dust irritation
  • May be preceded by pinguecula
  • Generally affects the field of vision
• Cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change: seen on the conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy
• Malignancies of the conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy:
  • Dermoids
  • Papillomas
  • Squamous cell carcinoma Squamous cell carcinoma Cutaneous squamous cell carcinoma (cSCC) is caused by malignant proliferation of atypical keratinocytes. This condition is the 2nd most common skin malignancy and usually affects sun-exposed areas of fair-skinned patients. The cancer presents as a firm, erythematous, keratotic plaque or papule. Squamous Cell Carcinoma (SCC)

Sclera Sclera The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. Eye: Anatomy

• Examined at the same time as the conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy
• Clinical relevance:
  • Yellow sclera Sclera The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. Eye: Anatomy: jaundice Jaundice Jaundice is the abnormal yellowing of the skin and/or sclera caused by the accumulation of bilirubin. Hyperbilirubinemia is caused by either an increase in bilirubin production or a decrease in the hepatic uptake, conjugation, or excretion of bilirubin. Jaundice due to liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy disease
  • Bluish discoloration: osteitis deformans Osteitis deformans Paget’s disease of bone (PDB), also known historically as osteitis deformans, is a focal disorder of bone metabolism that affects about 2%–9% of people. Commonly affected areas include the skull, spine, pelvis, and long bones of the lower extremity. The 2 main clinical manifestations of Paget’s disease are bone pain and the consequences of bone deformities. Paget’s Disease of Bone, Marfan’s syndrome
  • Inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation: A pink or purple circumscribed flat nodule Nodule Chalazion is seen with scleritis Scleritis Refers to any inflammation of the sclera including episcleritis, a benign condition affecting only the episclera, which is generally short-lived and easily treated. Classic scleritis, on the other hand, affects deeper tissue and is characterized by higher rates of visual acuity loss and even mortality, particularly in necrotizing form. Crohn’s Disease.
  • Episcleritis: deep, dusky patch Patch Nonpalpable lesion > 1 cm in diameter Generalized and Localized Rashes associated with marked inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation and ciliary congestion
  • Traumatic perforations can be seen in conditions of trauma.
  • Perforating trauma may communicate with the anterior chamber Anterior chamber The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. Eye: Anatomy.

Iris

• The “colored part” of the eye, examined in regular Regular Insulin light
• Anterior coloboma Coloboma Congenital anomaly in which some of the structures of the eye are absent due to incomplete fusion of the fetal intraocular fissure during gestation. Esophageal Atresia and Tracheoesophageal Fistula: a fissure Fissure A crack or split that extends into the dermis Generalized and Localized Rashes or cleft of the iris:
  • Uveal coloboma Coloboma Congenital anomaly in which some of the structures of the eye are absent due to incomplete fusion of the fetal intraocular fissure during gestation. Esophageal Atresia and Tracheoesophageal Fistula lends a “keyhole” or “cat-eye” appearance to the iris:
    • May be benign Benign Fibroadenoma
    • May be associated with serious lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy and optic nerve Optic nerve The 2nd cranial nerve which conveys visual information from the retina to the brain. The nerve carries the axons of the retinal ganglion cells which sort at the optic chiasm and continue via the optic tracts to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the superior colliculi and the suprachiasmatic nuclei. Though known as the second cranial nerve, it is considered part of the central nervous system. The 12 Cranial Nerves: Overview and Functions defects
• Synechiae Synechiae Scar tissue from prior surgery. Infertility: adhesions between the iris and other pupillary structures
  • Anterior synechiae Synechiae Scar tissue from prior surgery. Infertility are seen in:
    • Adherent leucoma
    • Leprosy Leprosy Leprosy, also known as Hansen’s disease, is a chronic bacterial infection caused by Mycobacterium leprae complex bacteria. Symptoms primarily affect the skin and peripheral nerves, resulting in cutaneous manifestations (e.g., hypopigmented macules) and neurologic manifestations (e.g., loss of sensation). Leprosy
    • Perforating corneal injury
  • Posterior synechiae Synechiae Scar tissue from prior surgery. Infertility: seen with iridocyclitis Iridocyclitis Acute or chronic inflammation of the iris and ciliary body characterized by exudates into the anterior chamber, discoloration of the iris, and constricted, sluggish pupil. Symptoms include radiating pain, photophobia, lacrimation, and interference with vision. Relapsing Fever
• Congenital Congenital Chorioretinitis heterochromia iridis (different colored irides in the same individual) may warrant further evaluation for:
  • Waardenburg syndrome Waardenburg syndrome Rare, autosomal dominant disease with variable penetrance and several known clinical types. Characteristics may include depigmentation of the hair and skin, congenital deafness, heterochromia iridis, medial eyebrow hyperplasia, hypertrophy of the nasal root, and especially dystopia canthorum. The underlying cause may be defective development of the neural crest (neurocristopathy). Waardenburg’s syndrome may be closely related to piebaldism. Klein-waardenburg syndrome refers to a disorder that also includes upper limb abnormalities. Hirschsprung Disease
  • Sturge-Weber syndrome Sturge-Weber Syndrome Sturge-Weber syndrome (SWS) is a congenital neurocutaneous disorder presenting with a facial birthmark called a port-wine stain (PWS), neurological abnormalities such as seizures, and eye abnormalities such as glaucoma. Sturge-Weber Syndrome (SWS)
  • Horner’s syndrome
• Iritis Iritis Inflammation of the iris characterized by circumcorneal injection, aqueous flare, keratotic precipitates, and constricted and sluggish pupil along with discoloration of the iris. Leprosy: leukocytes Leukocytes White blood cells. These include granular leukocytes (basophils; eosinophils; and neutrophils) as well as non-granular leukocytes (lymphocytes and monocytes). White Myeloid Cells: Histology in the anterior chamber Anterior chamber The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. Eye: Anatomy of the eye
• Anterior uveitis Uveitis Uveitis is the inflammation of the uvea, the pigmented middle layer of the eye, which comprises the iris, ciliary body, and choroid. The condition is categorized based on the site of disease; anterior uveitis is the most common. Diseases of the Uvea: inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of the iris and anterior ciliary body Ciliary body A ring of tissue extending from the scleral spur to the ora serrata of the retina. It consists of the uveal portion and the epithelial portion. The ciliary muscle is in the uveal portion and the ciliary processes are in the epithelial portion. Eye: Anatomy
• Iridocyclitis Iridocyclitis Acute or chronic inflammation of the iris and ciliary body characterized by exudates into the anterior chamber, discoloration of the iris, and constricted, sluggish pupil. Symptoms include radiating pain, photophobia, lacrimation, and interference with vision. Relapsing Fever: inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of iris and adjacent ciliary body Ciliary body A ring of tissue extending from the scleral spur to the ora serrata of the retina. It consists of the uveal portion and the epithelial portion. The ciliary muscle is in the uveal portion and the ciliary processes are in the epithelial portion. Eye: Anatomy
  • Most common type of uveitis Uveitis Uveitis is the inflammation of the uvea, the pigmented middle layer of the eye, which comprises the iris, ciliary body, and choroid. The condition is categorized based on the site of disease; anterior uveitis is the most common. Diseases of the Uvea
  • May be limited to the eye or may signify systemic disease
  • Associated with rheumatological conditions:
    • HLA-B27-related ankylosing spondylitis Ankylosing spondylitis Ankylosing spondylitis (also known as Bechterew’s disease or Marie-Strümpell disease) is a seronegative spondyloarthropathy characterized by chronic and indolent inflammation of the axial skeleton. Severe disease can lead to fusion and rigidity of the spine. Ankylosing Spondylitis
    • Psoriatic arthritis Psoriatic Arthritis A type of inflammatory arthritis associated with psoriasis, often involving the axial joints and the peripheral terminal interphalangeal joints. It is characterized by the presence of hla-b27-associated spondyloarthropathy, and the absence of rheumatoid factor. Psoriasis
    • Systemic lupus erythematosus Systemic lupus erythematosus Systemic lupus erythematosus (SLE) is a chronic autoimmune, inflammatory condition that causes immune-complex deposition in organs, resulting in systemic manifestations. Women, particularly those of African American descent, are more commonly affected. Systemic Lupus Erythematosus
  • Associated with infectious diseases:
    • Herpes zoster Herpes Zoster Varicella-zoster virus (VZV) is a linear, double-stranded DNA virus in the Herpesviridae family. Shingles (also known as herpes zoster) is more common in adults and occurs due to the reactivation of VZV. Varicella-Zoster Virus/Chickenpox
    • Cytomegalovirus Cytomegalovirus CMV is a ubiquitous double-stranded DNA virus belonging to the Herpesviridae family. CMV infections can be transmitted in bodily fluids, such as blood, saliva, urine, semen, and breast milk. The initial infection is usually asymptomatic in the immunocompetent host, or it can present with symptoms of mononucleosis. Cytomegalovirus
    • Toxoplasmosis Toxoplasmosis Toxoplasmosis is an infectious disease caused by Toxoplasma gondii, an obligate intracellular protozoan parasite. Felines are the definitive host, but transmission to humans can occur through contact with cat feces or the consumption of contaminated foods. The clinical presentation and complications depend on the host’s immune status. Toxoplasma/Toxoplasmosis
    • Syphilis Syphilis Syphilis is a bacterial infection caused by the spirochete Treponema pallidum pallidum (T. p. pallidum), which is usually spread through sexual contact. Syphilis has 4 clinical stages: primary, secondary, latent, and tertiary. Syphilis
    • TB TB Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis complex bacteria. The bacteria usually attack the lungs but can also damage other parts of the body. Approximately 30% of people around the world are infected with this pathogen, with the majority harboring a latent infection. Tuberculosis spreads through the air when a person with active pulmonary infection coughs or sneezes. Tuberculosis
  • Leukemia or lymphoma Lymphoma A general term for various neoplastic diseases of the lymphoid tissue. Imaging of the Mediastinum: may produce a leukocyte response that can be mistaken for inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation

Pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities

• Both eyes Both Eyes Refractive Errors should have round, symmetric pupils.
• Examine in dim light or in the dark with a flashlight to inspect:
  • Size
  • Shape
  • Color
  • Reactions
• Size:
  • Normal: 3–4 mm
  • Unequal size of pupils: anisocoria Anisocoria Unequal pupil size, which may represent a benign physiologic variant or a manifestation of disease. Pathologic anisocoria reflects an abnormality in the musculature of the iris (iris diseases) or in the parasympathetic or sympathetic pathways that innervate the pupil. Physiologic anisocoria refers to an asymmetry of pupil diameter, usually less than 2mm, that is not associated with disease. Pupil: Physiology and Abnormalities
    • May be a benign Benign Fibroadenoma physiologic condition that is longstanding (simple anisocoria Anisocoria Unequal pupil size, which may represent a benign physiologic variant or a manifestation of disease. Pathologic anisocoria reflects an abnormality in the musculature of the iris (iris diseases) or in the parasympathetic or sympathetic pathways that innervate the pupil. Physiologic anisocoria refers to an asymmetry of pupil diameter, usually less than 2mm, that is not associated with disease. Pupil: Physiology and Abnormalities)
    • May indicate an efferent Efferent Neurons which send impulses peripherally to activate muscles or secretory cells. Nervous System: Histology pupillary defect seen in:
      • Cranial nerve III palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies
      • Pharmacologic mydriasis Pharmacologic Mydriasis Pupil: Physiology and Abnormalities
      • Disorders of the iris
      • Horner syndrome Horner syndrome Horner syndrome is a condition resulting from an interruption of the sympathetic innervation of the eyes. The syndrome is usually idiopathic but can be directly caused by head and neck trauma, cerebrovascular disease, or a tumor of the CNS. Horner Syndrome/disturbance in the sympathetic pathway
  • Decreased size of the pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities ( miosis Miosis Pupil: Physiology and Abnormalities) seen with:
    • Effect of local miotic drugs
    • Iridocyclitis Iridocyclitis Acute or chronic inflammation of the iris and ciliary body characterized by exudates into the anterior chamber, discoloration of the iris, and constricted, sluggish pupil. Symptoms include radiating pain, photophobia, lacrimation, and interference with vision. Relapsing Fever
    • Horner’s syndrome Horner’S Syndrome Pupil: Physiology and Abnormalities
    • Head injury
    • Opioid Opioid Compounds with activity like opiate alkaloids, acting at opioid receptors. Properties include induction of analgesia or narcosis. Constipation use
  • Increased size of the pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities ( mydriasis Mydriasis Dilation of pupils to greater than 6 mm combined with failure of the pupils to constrict when stimulated with light. This condition may occur due to injury of the pupillary fibers in the oculomotor nerve, in acute angle-closure glaucoma, and in adie syndrome. Glaucoma) seen with:
    • Effect of local mydriatic drugs
    • Acute congestive glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma
    • Optic atrophy Atrophy Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes. Cellular Adaptation
    • Retinal detachment Retinal detachment Retinal detachment is the separation of the neurosensory retina from the retinal pigmented epithelium and choroid. Rhegmatogenous retinal detachment, the most common type, stems from a break in the retina, allowing fluid to accumulate in the subretinal space. Retinal Detachment
    • Cocaine Cocaine An alkaloid ester extracted from the leaves of plants including coca. It is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. It also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. Cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake. Local Anesthetics and stimulant use
• Shape (abnormal shape usually indicates prior surgery)
• Color (depends on the structures located behind the pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities):
  • Jet black in aphakia
  • Grayish white in immature senile cortical cataract Cortical Cataract Cataracts in Adults
  • Pearly white in mature cortical cataract Cortical Cataract Cataracts in Adults
  • Leukocoria Leukocoria Cataracts in Children (white reflex in pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities (see photo)) seen in:
    • Congenital Congenital Chorioretinitis cataract Cataract Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). Neurofibromatosis Type 2
    • Retinoblastoma Retinoblastoma Retinoblastoma is a rare tumor but the most common primary intraocular malignancy of childhood. It is believed that the condition arises from a neuronal progenitor cell. Retinoblastoma can be heritable or non-heritable. Retinoblastoma
    • Retrolental fibroplasia Fibroplasia Fibromuscular Dysplasia
  • Dirty white exudates are seen in iridocyclitis Iridocyclitis Acute or chronic inflammation of the iris and ciliary body characterized by exudates into the anterior chamber, discoloration of the iris, and constricted, sluggish pupil. Symptoms include radiating pain, photophobia, lacrimation, and interference with vision. Relapsing Fever.
• Pupillary exam for reactions:
  • Direct light reflex:
    • To elicit this reflex, the subject is seated in a dark room and a flashlight is used to elicit constriction. Repeat in the other eye.
    • A normal pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities reacts to light by constricting briskly.
  • Consensual light reflex:
    • A pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities is exposed to light and the response is noted in the other eye. The procedure is repeated for the other eye.
    • Normally, the contralateral pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities will constrict when bright light is directed at the ipsilateral pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities.
  • Swinging flashlight test:
    • To evaluate for an afferent Afferent Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology pathway defect
    • Shine a flashlight on 1 pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities and note the constriction. The flashlight is then moved to the other eye and the pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities response is noted.
    • The to-and-fro swinging motion is repeated several times while observing the response of the pupils.
    • Normal response: Both pupils constrict equally. In an afferent Afferent Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology pathway defect, the affected pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities will dilate when the flashlight is moved from the normal eye to the abnormal eye.
    • Known as Marcus Gunn pupil Marcus Gunn Pupil Pupil: Physiology and Abnormalities (relative afferent Afferent Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology pupillary defect)
  • Near reflex:
    • The subject is asked to focus on a distant object and then instructed to suddenly focus on an object held at about 15 cm from their eye.
    • Normal response: Constriction of the pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities is observed when the subject tries to focus on the nearby object.

Cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy

The cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy is examined with a slit lamp or after corneal staining.

• To examine for a corneal abrasion Abrasion Soft Tissue Abscess:
  • A drop of fluorescein Fluorescein A phthalic indicator dye that appears yellow-green in normal tear film and bright green in a more alkaline medium such as the aqueous humor. Pseudomonas dye is applied to the conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy at the inside corner of the eye.
  • Corneal abrasions Abrasions Corneal Abrasions, Erosion, and Ulcers or ulcers stain bright green with fluorescein Fluorescein A phthalic indicator dye that appears yellow-green in normal tear film and bright green in a more alkaline medium such as the aqueous humor. Pseudomonas when viewed under UV light UV light That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-uv or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-uv or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants. Bullous Pemphigoid and Pemphigus Vulgaris.
• Clinical relevance
  • Size (abnormalities diagnosed in infants):
    • Microcornea Microcornea Anomalies of the Cornea: horizontal diameter < 10 mm
    • Megalocornea Megalocornea Anomalies of the Cornea: horizontal diameter > 13 mm
  • Shape:
    • Normally, the cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy is a watch glass-like structure with a uniform posterior surface.
    • Keratometry and corneal topography tests are performed to analyze the curvature of the cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy.
    • Keratoconus Keratoconus A noninflammatory, usually bilateral protrusion of the cornea, the apex being displaced downward and nasally. It occurs most commonly in females at about puberty. The cause is unknown but hereditary factors may play a role. The -conus refers to the cone shape of the corneal protrusion. . Anomalies of the Cornea: conical shaping of the cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy
    • Cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy plana: Flattening of the cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy may occur in individuals as a congenital Congenital Chorioretinitis anomaly.
    • Astigmatism Astigmatism Unequal curvature of the refractive surfaces of the eye. Thus a point source of light cannot be brought to a point focus on the retina but is spread over a more or less diffuse area. This results from the radius of curvature in one plane being longer or shorter than the radius at right angles to it. . Refractive Errors:
      • Refractive condition
      • Warped corneal surface causes uneven focusing of light rays.
  • Sheen:
    • Normal cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy has a sheen.
    • Lost with “dry eye” conditions such as Sjögren syndrome Sjögren Syndrome Rheumatoid Arthritis
  • Sensation:
    • Blink reflex:
      • Examiner touches the corneal surface with a cotton wick.
      • Normal response is to blink.
      • May be impaired with neurologic conditions
    • Sensitivity of cornea Cornea The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous corneal epithelium; bowman membrane; corneal stroma; descemet membrane; and mesenchymal corneal endothelium. It serves as the first refracting medium of the eye. Eye: Anatomy is diminished in:
      • Herpetic keratitis Keratitis Inflammation of the cornea. Herpes Simplex Virus 1 and 2
      • Neuroparalytic keratitis Keratitis Inflammation of the cornea. Herpes Simplex Virus 1 and 2
      • Leprosy Leprosy Leprosy, also known as Hansen’s disease, is a chronic bacterial infection caused by Mycobacterium leprae complex bacteria. Symptoms primarily affect the skin and peripheral nerves, resulting in cutaneous manifestations (e.g., hypopigmented macules) and neurologic manifestations (e.g., loss of sensation). Leprosy
      • Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus mellitus
      • End-stage glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma
      • After trigeminal block for postherpetic neuralgia Postherpetic neuralgia Pain in nerves, frequently involving facial skin, resulting from the activation the latent varicella-zoster virus. The two forms of the condition preceding the pain are herpes zoster oticus; and herpes zoster ophthalmicus. Following the healing of the rashes and blisters, the pain sometimes persists. Herpes Zoster (Shingles)

Anterior chamber Anterior chamber The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. Eye: Anatomy

• Depth:
  • Measured using a slit lamp
  • Normal depth is 2.5 mm.
  • Shallow anterior chamber Anterior chamber The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. Eye: Anatomy is seen with:
    • Primary narrow-angle glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma
    • Anterior subluxation Subluxation Radial Head Subluxation (Nursemaid’s Elbow) of the lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy
  • Deep anterior chamber Anterior chamber The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. Eye: Anatomy is seen with:
    • Congenital Congenital Chorioretinitis aphakia (lack of lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy)
    • Myopia Myopia Refractive Errors
    • Keratoglobus Keratoglobus Anomalies of the Cornea
    • Keratoconus Keratoconus A noninflammatory, usually bilateral protrusion of the cornea, the apex being displaced downward and nasally. It occurs most commonly in females at about puberty. The cause is unknown but hereditary factors may play a role. The -conus refers to the cone shape of the corneal protrusion. . Anomalies of the Cornea
• Clinical relevance:
  • Hyphema Hyphema Bleeding in the anterior chamber of the eye. Corneal Abrasions, Erosion, and Ulcers (blood in the anterior chamber Anterior chamber The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. Eye: Anatomy) seen in:
    • Ocular trauma Ocular Trauma Cataracts in Children
    • Ocular surgery
    • Iridocyclitis Iridocyclitis Acute or chronic inflammation of the iris and ciliary body characterized by exudates into the anterior chamber, discoloration of the iris, and constricted, sluggish pupil. Symptoms include radiating pain, photophobia, lacrimation, and interference with vision. Relapsing Fever
  • Hypopyon Hypopyon Diseases of the Uvea (pus in the anterior chamber Anterior chamber The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. Eye: Anatomy) seen in:
    • Corneal ulcer Corneal ulcer Corneal ulcers are classified as corneal epithelial defects. These defects are differentiated from other corneal lesions according to their depth: ulcers extend into the underlying stroma. Corneal Abrasions, Erosion, and Ulcers
    • Iridocyclitis Iridocyclitis Acute or chronic inflammation of the iris and ciliary body characterized by exudates into the anterior chamber, discoloration of the iris, and constricted, sluggish pupil. Symptoms include radiating pain, photophobia, lacrimation, and interference with vision. Relapsing Fever
    • Endophthalmitis Endophthalmitis Endophthalmitis is an inflammatory process of the inner layers of the eye, which may be either infectious or sterile. Infectious endophthalmitis can lead to irreversible vision loss if not treated quickly. Based on the entry mode of the infectious source, endophthalmitis is divided into endogenous and exogenous types. Endophthalmitis
  • Aqueous flare (inflammatory cells in the anterior chamber Anterior chamber The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. Eye: Anatomy): seen as fine moving particles in cases of iridocyclitis Iridocyclitis Acute or chronic inflammation of the iris and ciliary body characterized by exudates into the anterior chamber, discoloration of the iris, and constricted, sluggish pupil. Symptoms include radiating pain, photophobia, lacrimation, and interference with vision. Relapsing Fever
  • Foreign bodies may be found after traumatic injury (e.g., wood, iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements, glass particles, stone particles, eyelashes).

Lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy

Examination of the lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy is done using a slit lamp after fully dilating the pupils.

• Position:
  • Dislocation:
    • Anteriorly into the anterior chamber Anterior chamber The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. Eye: Anatomy
    • Posteriorly into the vitreous chamber Vitreous chamber Eye: Anatomy
  • Subluxation Subluxation Radial Head Subluxation (Nursemaid’s Elbow):
    • Partial displacement Displacement The process by which an emotional or behavioral response that is appropriate for one situation appears in another situation for which it is inappropriate. Defense Mechanisms of the lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy from its position
    • Observed as a shining golden crescent Crescent Rapidly Progressive Glomerulonephritis on focal illumination
    • Observed as a dark line on distant direct ophthalmoscopy
  • Clinical relevance: may have dislocation or subluxation Subluxation Radial Head Subluxation (Nursemaid’s Elbow) with trauma
• Transparency:
  • Opacity Opacity Imaging of the Lungs and Pleura is indicative of a cataract Cataract Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). Neurofibromatosis Type 2.
  • Grayish or yellowish white
  • Clinical relevance of cataracts seen on ophthalmoscopy:
    • Congenital Congenital Chorioretinitis
    • Develop with aging and sun exposure
    • Side effect of corticosteroids Corticosteroids Chorioretinitis
    • Diabetic cataract Cataract Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). Neurofibromatosis Type 2: “snowflake opacities”
    • Wilson disease Wilson disease Wilson disease (hepatolenticular degeneration) is an autosomal recessive disorder caused by various mutations in the ATP7B gene, which regulates copper transport within hepatocytes. Dysfunction of this transport mechanism leads to abnormal copper accumulations in the liver, brain, eyes, and other organs, with consequent major and variably expressed hepatic, neurologic, and psychiatric disturbances. Wilson Disease: “ sunflower cataract Sunflower Cataract Cataracts in Adults”
    • Concussion injury of the lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy: “rosette-shaped cataracts”

Testing the intraocular pressure

• Normal intraocular pressure: 10–21 mm Hg
• Equipment used in screening Screening Preoperative Care for glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma:
  • Indentation tonometer (Schiotz tonometer)
  • Applanation tonometer (Goldman tonometer)
• Clinical relevance
  • Ocular hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension:
    • Increased intraocular pressure Increased intraocular pressure An ocular disease, occurring in many forms, having as its primary characteristics an unstable or a sustained increase in the intraocular pressure which the eye cannot withstand without damage to its structure or impairment of its function. The consequences of the increased pressure may be manifested in a variety of symptoms, depending upon type and severity, such as excavation of the optic disk, hardness of the eyeball, corneal anesthesia, reduced visual acuity, seeing of colored halos around lights, disturbed dark adaptation, visual field defects, and headaches. Osmotic Diuretics
    • No damage to optic structures and normal visual fields
    • Risk factor for glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma
  • Glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma:
    • Elevated intraocular pressure with optic nerve Optic nerve The 2nd cranial nerve which conveys visual information from the retina to the brain. The nerve carries the axons of the retinal ganglion cells which sort at the optic chiasm and continue via the optic tracts to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the superior colliculi and the suprachiasmatic nuclei. Though known as the second cranial nerve, it is considered part of the central nervous system. The 12 Cranial Nerves: Overview and Functions damage
    • Symptoms:
      • Blurred vision Blurred Vision Retinal Detachment
      • Blindness Blindness The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of eye diseases; optic nerve diseases; optic chiasm diseases; or brain diseases affecting the visual pathways or occipital lobe. Retinopathy of Prematurity
      • Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways in the eye
    • Requires immediate treatment to prevent vision loss

Examination of the Fundus

Examination of the fundus Fundus The superior portion of the body of the stomach above the level of the cardiac notch. Stomach: Anatomy is important to diagnose disorders of the vitreous humor Humor Defense Mechanisms, optic nerve Optic nerve The 2nd cranial nerve which conveys visual information from the retina to the brain. The nerve carries the axons of the retinal ganglion cells which sort at the optic chiasm and continue via the optic tracts to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the superior colliculi and the suprachiasmatic nuclei. Though known as the second cranial nerve, it is considered part of the central nervous system. The 12 Cranial Nerves: Overview and Functions, choroid Choroid The thin, highly vascular membrane covering most of the posterior of the eye between the retina and sclera. Eye: Anatomy, and retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy.

• Dilate the pupil Pupil The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil’s size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. Pupil: Physiology and Abnormalities with a mydriatic agent:
  • Phenylephrine Phenylephrine An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent. Sympathomimetic Drugs
  • Atropine Atropine An alkaloid, originally from atropa belladonna, but found in other plants, mainly solanaceae. Hyoscyamine is the 3(s)-endo isomer of atropine. Anticholinergic Drugs
  • Tropicamide Tropicamide One of the muscarinic antagonists with pharmacologic action similar to atropine and used mainly as an ophthalmic parasympatholytic or mydriatic. Anticholinergic Drugs
  • Cyclopentolate Cyclopentolate A parasympatholytic anticholinergic used solely to obtain mydriasis or cycloplegia. Anticholinergic Drugs
• Fundus Fundus The superior portion of the body of the stomach above the level of the cardiac notch. Stomach: Anatomy can be examined using an ophthalmoscope:
  • Ocular media should be transparent.
  • Opacification can be seen with:
    • Corneal opacity Opacity Imaging of the Lungs and Pleura (e.g., keratitis Keratitis Inflammation of the cornea. Herpes Simplex Virus 1 and 2)
    • Lenticular opacity Opacity Imaging of the Lungs and Pleura (e.g., cataract Cataract Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). Neurofibromatosis Type 2)
    • Vitreous opacities (e.g., hemorrhage)
• Clinical relevance:
  • Examination of retinal blood vessels and abnormal findings:
    • Arterioles Arterioles The smallest divisions of the arteries located between the muscular arteries and the capillaries. Arteries: Histology appear bright red and venules Venules The minute vessels that collect blood from the capillary plexuses and join together to form veins. Veins: Histology appear purplish.
    • Narrowing of arterioles Arterioles The smallest divisions of the arteries located between the muscular arteries and the capillaries. Arteries: Histology may be seen in:
      • Hypertensive retinopathy Retinopathy Degenerative changes to the retina due to hypertension. Alport Syndrome
      • Arteriosclerosis
      • Central retinal artery occlusion Retinal Artery Occlusion Retinal Vessel Occlusion
    • Tortuosity of veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology may be seen in:
      • Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus mellitus
      • Central retinal vein occlusion Retinal Vein Occlusion Retinal Vessel Occlusion
      • Blood dyscrasias
    • Drusen Drusen Colloid or hyaline bodies lying beneath the retinal pigment epithelium. They may occur either secondary to changes in the choroid that affect the pigment epithelium or as an autosomal dominant disorder of the retinal pigment epithelium. Nephritic Syndrome (yellow lipid deposits under the retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy) seen in:
      • Normal with advancing age
      • Early sign of macular degeneration Macular degeneration Age-related macular degeneration (AMD) is visual impairment due to changes in the macula, the area responsible for high-acuity vision. It is marked by central vision loss with peripheral vision relatively spared. Risk factors include advanced age, smoking, family history, and cardiovascular disease. Macular Degeneration
  • Optic disc Optic disc The portion of the optic nerve seen in the fundus with the ophthalmoscope. It is formed by the meeting of all the retinal ganglion cell axons as they enter the optic nerve. Eye: Anatomy exam and abnormal findings:
    • Connection of the optic nerve Optic nerve The 2nd cranial nerve which conveys visual information from the retina to the brain. The nerve carries the axons of the retinal ganglion cells which sort at the optic chiasm and continue via the optic tracts to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the superior colliculi and the suprachiasmatic nuclei. Though known as the second cranial nerve, it is considered part of the central nervous system. The 12 Cranial Nerves: Overview and Functions to the retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy
    • Pinkish white, 1.5-mm circular structure with a central “cup”
    • Hyperemia of the disk seen in:
      • Papilledema Papilledema Swelling of the optic disk, usually in association with increased intracranial pressure, characterized by hyperemia, blurring of the disk margins, microhemorrhages, blind spot enlargement, and engorgement of retinal veins. Chronic papilledema may cause optic atrophy and visual loss. Idiopathic Intracranial Hypertension
      • Papillitis
    • Pallor of the disc: sign of optic atrophy Atrophy Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes. Cellular Adaptation
    • The normal cup to disk ratio is 0.3 and may be increased in glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma.
    • Neovascularization of the disk may occur in:
      • Diabetic retinopathy Diabetic retinopathy Disease of the retina as a complication of diabetes mellitus. It is characterized by the progressive microvascular complications, such as aneurysm, intraretinal edema, and intraocular pathologic neovascularization. Chronic Diabetic Complications
      • Sickle cell retinopathy Retinopathy Degenerative changes to the retina due to hypertension. Alport Syndrome
  • Macular exam and abnormal findings (usually requires a slit-lamp exam):
    • Normal macula Macula An oval area in the retina, 3 to 5 mm in diameter, usually located temporal to the posterior pole of the eye and slightly below the level of the optic disk. It is characterized by the presence of a yellow pigment diffusely permeating the inner layers, contains the fovea centralis in its center, and provides the best phototropic visual acuity. It is devoid of retinal blood vessels, except in its periphery, and receives nourishment from the choriocapillaris of the choroid. Eye: Anatomy is slightly darker than the surrounding retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy.
    • Center imparts a bright reflex (foveal reflex).
    • Macular hole: a round, full-thickness defect of retinal tissue in the foveal retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy leading to the loss of central vision
    • Cherry-red spot seen in:
      • Central retinal artery occlusion Retinal Artery Occlusion Retinal Vessel Occlusion
      • Tay-Sachs disease Tay-Sachs disease Tay-Sachs disease is an autosomal recessive lysosomal storage disorder caused by genetic mutations in the hexosaminidase A (HEXA) gene, leading to progressive neurodegeneration. Classic symptoms in infants include rapid degeneration of cognitive and neuromuscular abilities, progressive blindness, and a macular cherry-red spot on physical examination. Tay-Sachs Disease
      • Niemann-Pick disease Niemann-Pick disease Niemann-Pick disease (NPD) is a rare, inherited, lysosomal storage disorder. The disease is classified on the basis of the genetic mutation. Type A and type B result from mutations in the SMPD-1 gene, resulting in acid sphingomyelinase enzyme deficiency. Type C results from NPC1 or NPC2 gene mutations, which are needed for intracellular transport of lipids. Niemann-Pick Disease
      • Gaucher’s disease
    • Macular edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema seen in:
      • Trauma
      • Intraocular operations
      • Uveitis Uveitis Uveitis is the inflammation of the uvea, the pigmented middle layer of the eye, which comprises the iris, ciliary body, and choroid. The condition is categorized based on the site of disease; anterior uveitis is the most common. Diseases of the Uvea
      • Diabetic maculopathy
    • Hard exudates seen in:
      • Diabetic retinopathy Diabetic retinopathy Disease of the retina as a complication of diabetes mellitus. It is characterized by the progressive microvascular complications, such as aneurysm, intraretinal edema, and intraocular pathologic neovascularization. Chronic Diabetic Complications
      • Hypertensive retinopathy Retinopathy Degenerative changes to the retina due to hypertension. Alport Syndrome
    • Pale macula Macula An oval area in the retina, 3 to 5 mm in diameter, usually located temporal to the posterior pole of the eye and slightly below the level of the optic disk. It is characterized by the presence of a yellow pigment diffusely permeating the inner layers, contains the fovea centralis in its center, and provides the best phototropic visual acuity. It is devoid of retinal blood vessels, except in its periphery, and receives nourishment from the choriocapillaris of the choroid. Eye: Anatomy: seen with macular degeneration Macular degeneration Age-related macular degeneration (AMD) is visual impairment due to changes in the macula, the area responsible for high-acuity vision. It is marked by central vision loss with peripheral vision relatively spared. Risk factors include advanced age, smoking, family history, and cardiovascular disease. Macular Degeneration in elderly individuals