This 69YO male presented with a few months of blurred vision in his left eye. Vision was 20/40 in his normal right eye and 20/100 in his left eye.
Scattered deep retinal hemorrhages are noted temporally. Fluorescein angiography shows temporal midperipheral microaneurysms, more distal ischemia with vascular leakage, and moderate cystoid macular leakage.
Since our patient had a history of a complete left internal carotid artery blockage, no further testing was ordered. He is currently monitored regularly by a vascular surgeon.
Learning Points:
The retinal hemorrhages in the ocular ischemic syndrome (OIS) are unique. Retinal vascular disorders like diabetic retinopathy, retinal vein occlusions, and hypertensive retinopathy usually have flame- and dot-shaped inner retinal hemorrhages concentrated around the posterior pole.
Our patient’s findings are classic for OIS, with hemorrhages in the deeper peripheral retina. The retinal periphery is literally the end of the line for the retinal arterial circulation. In an eye receiving less blood supply due to carotid occlusive disease, the more proximal retina has first dibs on the available oxygen.
There are penetrating capillaries that dive radially from the nerve fiber and ganglion cell layers into the deeper retina. The deep vascular complex that supplies the inner and outer plexiform layers is thus furthest downstream, and these endothelial cells are likely damaged in OIS. Blood cells leaking into this space accumulate, causing the large outer blot to hemorrhage.
These patients need to have carotid Doppler and ultrasound and referred for medical or surgical intervention if they have a critical stenosis. They may also develop anterior or posterior segment neovascularization requiring photocoagulation and/or anti-VEGF injections.
