Venous stasis retinopathy (OIS) is caused by what underlying issue?

• A. Blockage in the carotid artery preventing adequate retinal blood flow
• B. Increased intraocular pressure
• C. Uveitis
• D. Cataract

Answer: (A)

Venous stasis retinopathy is a manifestation of ocular ischemic syndrome, caused by reduced blood flow to the retina due to carotid artery disease. When the carotid is blocked or severely narrowed, the ophthalmic artery receives less blood, lowering retinal arterial inflow and ocular perfusion pressure. This ischemic environment leads to retinal venous dilation and stagnation as the veins become congested, producing the venous stasis changes seen clinically.

The other options don’t fit as the underlying cause: higher intraocular pressure is linked to glaucoma and optic nerve damage rather than retinal venous congestion from ischemia; uveitis is inflammatory; cataract is a lens opacity. The carotid blockage best explains the retinal ischemia and resultant venous stasis pattern.