Cattle track appearance on fundoscopy is seen in -
Ans. is 'a' i.e., CRAO Central Retinal Artery Occlusion (CRAP)o The circulation to the retina enters the eye through the central retinal artery. Therefore, its blockade causes severe ischemia to retina. Patient notices sudden painless loss of vision, within a few minutes the eye may become totally blind. Patients's with a patent cilioretinal artery may retain central vision as the macula is sparedo Of all retinal artery occlusions 60% involve central retinal artery, 35% involve branch retinal artery and 5% involve cilioretinal artery. Emboli are the most common cause of retinal artery occlusion. Source of emboli may be i) atheroma in carotid artery; or ii) Mural thrombi secondary to MI or AF; or iii) Mitral valve prolase. Other causes are giant cell arteritis, SLE, wegener's granulomatosis, scleroderma, and occasionally raised IOP.o Complete obstruction of the central retinal artery presents a characteristic ophthalmological picture a few hours after the attack. The larger retinal arteries are constricted and look like thin threads while the smaller vessels are scarcely visible. The fundus appears milky white because of retinal edema. There is cherry-red spot at the macula. Hemorrhages are not seen in CRAO unless the vein is also occluded. Blood column within the retinal veins is segmented (Cattle-tracking). After a few weeks, the retinal swelling subsides and the retina regains its transparency but the disc becomes pale because of atrophy. The retinal arterioles remain narrow.
CRAO
BRVO
Central serous Retinopathy
Cystoid macular edema
Vascular Disorders