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What is "Cattle truck" appearance on fundoscopy and explain in detail?
Ans. c (Central retinal artery occlusion (Ref: Parson's 20lh/302, A K Khurana 2nd/26, 253)CENTRAL RETINAL ARTERY OCCLUSION (CRAO)# Etiology/pathogenesis- There is usually an embolus or thrombus.- A yellow cholesterol embolus (Hollenhorst plaque) on the head of the optic nerve or in a branch of retinal artery confirms the diagnosis.- The most important causes of emboli are atherosclerotic plaques of the carotid arteries, arterial hypertension, and cardiac valve lesions.# Epidemiology- The prevalence of CRAO is 0.85 per 100,000 population in one year.- It is a disease of adulthood (in the sixth decade of life on average).- More common in males than in females. Involvement is bilateral in 1-2%, with the exception of temporal arteritis and other systemic vasculitides.# Clinical features- Patients present with sudden painless loss of vision.- Usually unilateral.- Direct pupillary light reflex is absent.- Retinal arteries are markedly narrowed.- Central part of mascular area shows 'cherry-red' spot due to vascular choroid shining through thin retina.- Segmented blood column within retinal veins ('cattle- track' appearance) is pathognomonic of central retinal artery occlusion.- The arteries are thin and the segmented blood flow in the retinal arteries can be observed in acute stages of the disease.# Diagnosis- Diagnosis is made clinically.- The diagnosis can be confirmed by fluorescence angiography.# Differential diagnosis- Differentiation between arteritic (Horton disease) and nonarteritic CRAO is very important because in Horton disease the fellow eye can become involved within a few days without appropriate treatment.# Treatment- There is no consensus currently about the efficacy of different forms of treatment.- Conservative treatment: globe massage, anterior chamber paracentesis, infusion treatment with pentoxifylline, hyperbaric oxygen, intravenous rTPA, or corticosteroid injection.- Invasive treatment: selective catheterization of the ophthalmic artery with administration of fibrinolytic drugs.# Prognosis.- The visual acuity on first presentation generally decides the prognosis.- Spontaneous improvements are observed in up to 15%.Various fundoscopic appearance Appearance on FundoscopyDiagnosis1Pinkish with central area of pallorNormal disc2HyperemiaPapilledema, papillitis3Pale discPartial optic atrophy4'Chalky white' discPrimary optic atrophy5'Yellow waxy' discConsecutive optic atroph6'Shot-silk' fundusPseudopapilitis7'Champagne pale cork'fundusChronic papilledema8Pale waxy disc with 'bone corpuscles' like pigmentary changesRetinitis pigmentosa9'Cattle truck' appearance (of retinal veins)CRAO10'Ink-blot/ Enlarging dot' pattern/ 'Smoke stake' patternCentral serous retinopathy11'Flower petal' appearanceCystoid macular edema12'Cotton wool'spotsMost common abnormality in AIDS13'Tomato sauce and cheese' OR 'Crumbled cheese and Ketchup' OR 'Brush-fire' OR 'Pizza pie' appearanceCMV retinitis14.Angioid streaks# Pseudoxanthoma elasticum# Pagets disease of bone,# Ehler Danlos disease# Sickle cell disease.15.Bull's eye maculopathyChloroquine16.Severe retinal telangiectesiaCoat's disease17.'Salt and pepper' fundus# Congenital rubella, syphilis, HSV, Varicella, mumps# Leber's amaurosis# Mayous-Batten disease# Thioridazine toxicity# Cancer associated retinopathy# Carriers of Choroideremia, albinism, Retininitis Pigmentosa.18."Sea Fan" RetinaSickle cell disease19.'Candle wax'appearanceSarcoid retinopathy20.Cherry Red spots(Mnemonic: Pick My QT Bags)# Niemann-Pick's disease# Multiple sulfatase deficiency# Quinine amblyopia# TaySachs disease# Berlin's edema (Commontio retinae) due to blunt trauma# CRAO# Gaucher's disease# Sandhoff disease# Sialidosis type 1 and 221.Cherry red spotsNOT seen in CRVOIn CRVO, Rubeosis iridis develops in about 50% of eyes, usually in 3 months (100-day glaucoma), and there is a high risk of neovascular glaucoma.