Which of the following is best to differentiate CRVO from carotid artery occlusion. (AIPG 2009)
|A||Dilated retinal vein|
|B||Retinal artery pressure|
|C||Tortuous retinal vein|
1. Ophthalmodynamometry represents an attempt to measure the blood pressure of the ophthalmic artery.
2. Diagnostic tool in carotid artery insufficiency states where these is
3. Decreased ophthalmic artery pressure resulting from carotid insufficiency.
4. The diagnosis of CRVO can usually be made based on characteristic ophthalmoscopic findings including retinal hemorrhage in all quadrants, dilated and tortuous veins, and cotton-wool spots. Two significant vision-threatening complications are persistent macular edema and neovascular glaucoma.
Pathophysiology of CRVO
1. Thrombosis at the level of the lamina cribrosa.
2. Compression of the central vein in this region may increase turbulence and slow blood flow, leading to endothelial damage and thrombus formation.
3. In the region of the lamina cribrosa (unlike other areas of the optic nerve), the central artery and vein share a common tunic of connective tissue, rendering the thin-walled vein vulnerable to compression by an artery thickened and hardened by arteriosclerosis and hypertension.
4. Venous occlusion causes slowing of blood flow with resultant hypoxia, endothelial cell damage, and disruption of the blood-retina barrier.