Foromar

When the central retinal vein, the main vein that drains blood away from the retina, becomes occluded, the vision usually becomes blurred but does not black out completely. The vein occlusion affects the circulation to the retina, although many people who have central retinal vein occlusions may already have somewhat compromised circulation because of hardening of the arteries in the neck or closer to the eye. The typical appearance of the retina in this situation has been called one of “blood and thunder.” Severe hemorrhaging and leakage from the blood vessels are seen throughout the retina, and the veins appear dark and swollen. In contrast to this picture is a less severe type of central retinal vein occlusion called venous stasis retinopathy. In this form, there is much less hemorrhaging, the vision may remain fairly good, the circulation to the retina is fairly good, and the prognosis over all is much better. Occlusions of branches of the central retinal vein also occur. Sometimes the indentation of the veins by the arteries that cross over them may play a role.