00:00
Finally, Hypertensive Retinopathy. Relatively common because hypertension is a big deal or
very common pathology we see in the human condition. It's going to be due to elevated
systemic and then specifically elevated retinal artery pressures. So what's going on here?
There are different faces in the pathophysiology in the development of hypertensive
retinopathy. So, in the vasoconstrictive phase, so the eye wants to very carefully regulate
the blood pressure into the eye so if there is increased systemic pressure coming in through
the retinal artery, the artery responds by doing reflex of vasoconstriction that reduces the
flow and so you'll get generalized retinal artery narrowing. That keeps the pressure
appropriate into the eye, but that reflex vasoconstriction is also going to be a nidus, an area
where we will have a preferential development of atherosclerotic vessel segments. Now,
those vessels, with that kind of change, cannot have improved vascular flow when they need
it and so there is a relative now obstruction to flow that is reducing flow into the eye, but
also causing much higher flow retrograde. And that higher pressure retrograde is going to be
reflected in a number of manifestations. So, we are going to get ruptured vessels. These are
relatively thin-walled arterioles so we will get in the eye that we can see on fundoscopic
exam a flame-shaped hemorrhage, so-called flame shaped. Literally it kind of a rupture of the
blood vessel and so-called dot blot hemorrhages. Again, rupture, focal, discontinuities within
the arterioles. We will get microaneurysms as we get vascular outpouching as a result of the
increased retrograde pressure. We will get accumulation of lipid and protein because under
increased pressure we will get exudates that accumulate. So we will see hard exudates that
are associated with this. And now because of this area in the middle where we have
increased atherosclerotic damage, then we're going to get retinal ischemia and microinfarcts
and so we'll see cotton wool spots. That's what's going on with hypertensive retinopathy.
02:37
Here's a pretty gnarly looking 2 eyes associated. So the fundoscopic exam in a patient who
has such severe end-stage hypertensive retinopathy, the cotton wool spots that we're
seeing there identified or retinal ischemia microinfarcts. There will be hemorrhages again
because we have ruptured the blood vessels with all that proximal increase in blood
pressure. We'll have papilloedema. So this is due to ischemia of the optic nerve with swelling
and you see an increased pallor around the optic disc. There will be arteriovenous nicking.
03:15
So, when you look very carefully there, you see that that vein as it's going along suddenly
seems to have a discontinuity in that. Well that's because that there is a thickened arteriole
that's crossing that, compressing it, and narrowing that venule that gives you the apparent
nicking on the fundoscopic exam. And you'll see copper wiring. So normally an arteriole has a
kind of a central clear yellow area. This gets accentuated. The light reflex that allows us to
see artery versus vein on a fundoscopic exam is accentuated in the setting because of their
arteriosclerotic changes that are happening in the vessel with chronic hypertension. Now
most patients even with systemic hypertension, most hypertensive patients are
asymptomatic and that's true of the hypertensive retinopathy. They may not be aware at
all that there is anything going on until much further along distally in the disease near the
end. They may get headaches with papilloedema, that pressure on the optic nerve, you will
get headaches and can get nausea and vomiting as well in severe cases. Because of the
papilloedema, because of the excess water in the interstitial connective tissue, we're
going to see decreased or blurry vision and you can get vision loss but this usually occurs
as a secondary consequence of optic atrophy and/or retinal detachment. And with that, we
have covered kind of 3 major retinal diseases; diabetic retinopathy, retinopathy of
prematurity, and hypertensive retinopathy. Hope you enjoyed it.