1.CPC Ophthalmology DR ABDUL MUNIM KHAN ASSOCIATE PROFESSOR AND HOD EYE DEPARTMENT MBBS-MC MIRPUR AJK

2. Patient History A 55 year old man Resident of Murree lower middle class socio-ecnomicaly Married Shopkeeper by profession Presented with a history of sudden loss of vision in his right eye 7 days 3. Patient was alright 5 days back when he suddenly developed loss of vision in right eye The loss of vision was sudden, painless and severe Not accompanied by any other symptoms no history of transient visual loss, no history of scalp tenderness, weight loss, jaw claudication, headache, polymyalgia rheumatic and fever 4. Patient consulted local health care provider who gave him some eye drops but the vision didnt improve so the health care provider advised him to go to some big hospital in Rawalpindi, patient went to Amanat Eye Hospital where he was investigated and now he is seeking a second opinion Past medical history Smoker one pack of cigarettes / day since his youth hypertensive on medication since last 7-8 years Past surgical history insignificant 5. GPE Anxious looking middle aged man pulse regular 90 beats / min BP 160/95 mm Hg, carotid and superficial temporal artery pulses palpable no carotid bruit Systemic examination otherwise unremarkable 6. Ocular examination Right eye vision PL+ Pupil very sluggish RAPD + early lens changes Fundoscopy: macular edema with cherry red spot Narrowed irregular arterioles and venules A whitish small mass on the disc (calcific embolus) Left vision 6/9 Not significant except early lens changes 7. D/D sudden loss of vision CRVO RD Vitreous hemorrhage ON AION CRAO 8. DD cherry red spot Metabolic Storage Diseases: Mucopolysaccharidosis Hurler's disease Tay-Sachs disease Lysosomal Storage Diseases Vascular: Central retinal artery occlusion Drugs: Quinine toxicity Dapsone toxicity Poisoning: Carbon monoxide Methanol 9. Diagnosis Central artery occlusion 10. CRAO is among the most dramatic problems encountered by an ophthalmologist Sudden Severe Permanent Life threatening implications 11. In 1859, Van Graefe first described central retinal artery occlusion (CRAO) in a patient with endocarditis due to embolic valvular vegetations in 1868, Mauthner suggested that spasmodic contractions could lead to retinal artery occlusion. In1881 Samelsohn advocated treatment with nitrate inhalation In 1888 Mules did AC paracenteses for CRAO 12. Incidence of CRAO 0.85/100,000 per year. Of these patients, 1-2% present with bilateral involvement. Mortality Life expectancy of patients with CRAO is 5.5 years compared to 15.4 years for an age-matched population without CRAO. 13. Sex Men are affected slightly more frequently than women. Age The mean age of presentation is in the early 60s, although a few cases have been reported in patients younger than 30 years 14. Retinal Survival Time Electrophysiologic and histopathologic examination showed that the retina of rhesus monkeys suffered no detectable damage with CRAO of 97 min But beyond that time, the longer the duration of CRAO, the more extensive the irreversible damage. The study suggested that CRAO lasting for about 240 min results in massive irreversible retinal damage. (Sohan Singh Hayreh et al 2004) 15. Causes Atheroma thrombosis related at the level of lamina cribrosa Carotid embolism (cholesterol, calcific, fibrinoplatelet) Cardiac embolism from the heart and its valves may consist of calcific material, vegetations in bacterial endocarditis and thrombus from the left side of the heart Giant cell arteritis (temporal) Periarteritis associated with dermatomyositis, systemic lupus erythematosus, polyarteritis nodosa, Wegener granulomatosis and Behet syndrome Sickling haemoglobinopathies. Retinal migraine may very rarely be responsible for retinal artery occlusion in young individuals. 16. Atherosclerosis-related thrombosis Atherosclerosis-related thrombosis at lamina cribrosa is by far the most common cause of CRAO (80% of cases). Atherosclerosis is characterized by focal intimal thickening (smooth muscle origin cells, connective tissue and lipid- containing foam cells) The incidence of atherosclerosis increases with age and is accelerated by hypertension, hyperlipidaemia, diabetes, oral contraceptives. Other risk factors include obesity, tobacco smoking and a sedentary lifestyle 17. Carotid embolism Embolus originates from atheromatous plaque at the carotid bifurcation, embolic material from the heart and carotid arteries has a direct route to the eye. types: 1 Cholesterol emboli (Hollenhorst plaques) appear as intermittent showers of minute, refractile, yellow-orange crystals, located at arteriolar bifurcations 2 Calcific emboli originate from atheromatous plaques or calcified heart valves. usually single, white, non-scintillating and on or close to the disc result in permanent occlusion 3 Fibrin-platelet emboli are dull grey, elongated particles which are usually multiple usually result in amaurosis fugax 18. Pathologic changes inner layer edema and pyknosis of the ganglion cell nuclei. Ischemic necrosis results, and the retina becomes opacified which is most dense in the posterior pole due to increased thickness of the nerve fiber layer and ganglion cells in this region. Foveola assumes a cherry-red spot appearance because of the foveolar retina is nourished by the choriocapillaris and RPE and choroid are intact The late stage shows a homogenous scar replacing the inner layer of the retina 19. Clinical Features It is characterized by a severe loss of vision associated with an afferent pupillary conduction defect. Some patients may give a history of amaurosis fugax involving transient loss of vision lasting seconds to minutes but which may last up to 2 hours. The vision usually returns to baseline after an episode of amaurosis fugax. 20. The retina appears whjte and edcmatous, especially at the posterior pole where the nerve fibre and ganglion cell layers are thickest. The foveola is devoid of these layers, which are relocated in the peri- foveolar retina, the orange reflex from the intact choroidal vessels beneath the foveola stands out in contrast to the surrounding opaque retina, giving rise to the 'cherry-red spot' appearance 21. marked narrowing of the retinal arterioles associated with irregularities in their calibre. Sludging and segmentation of the blood column may be 'seen in both arterioles and venules. if the occlusion persists, the retinal haze and the 'cherry-red spot' disappear after a few weeks arterioles, however, remain attenuated and eventually the optic disc becomes atrophic and pale Between 1% and 5% of eves with central retinal artery occlusion develop rubeosis iridis, which may be complicated by neovascular glaucoma 22. In about one in five cases, a portion of the papillomacular bundle is supplied by one or more cilioretinal arterioles from the ciliary circulation, and in these cases central vision may be preserved. 23. Systemic examination in a patient of CRAO should specially include Pulse particularly to detect atrial fibrillation. Blood pressure for hypertension Cardiac auscultation arrhythmias and murmurs Carotid examination. a Palpation of severe or complete stenosis is associated with a diminished or absent carotid pulse. b Auscultation over a partial stenosis gives rise to a bruit, best detected with the bell of the stethoscope. 24. Investigations to be carried out in patients of CRAO ECG to detect arrhythmia and other cardiac disease. Erythrocyte sedimentation rate and C-reactive protein to detect the remote possibility of GCA. Other blood tests include FBC, random glucose, lipids, urea and electrolytes. Carotid duplex scanning is a non-invasive screening test involving a combination of high-resolution real-time ultrasonography with Doppler flow analysis. If significant stenosis is present, surgical management may be considered 25. Treatment Usually occlusions are incomplete so it is recommended to treat patients who present with in 48 hours of occlusion 1 Adoption of a supine posture might improve ocular perfusion. 2 Ocular massage using a three-mirror contact lens (allows direct artery visualization) for approximately 10 seconds, aiming to achieve central retinal artery pulsation, followed by 5 seconds of release. The aim is to mechanically collapse the arterial lumen and cause changes in arterial flow. Self-massage through closed eyelids can be continued by the patient. 3 Anterior chamber paracentesis should be carried out in most cases. Instil povidone-iodine 5% and topical antibiotic prior to the procedure and a short course of antibiotic afterwards. 4 Topical timolol 0.5% and intravenous acetazolamide 500 mg to achieve a more sustained lowering of intraocular pressure. 26. 5 Sublingual isosorbide dinitrate to induce vasodilation. 6 Rebreathing into a paper bag in order to elevate blood carbon dioxide and respiratory acidosis, as this may promote vasodilation. 7 Breathing a high oxygen (95%) and carbon dioxide (5%) mixture,carbogen for a possible dual effect of retarding ischaemia and vasodilation. 8 Hyperosmotic agents. Mannitol or glycerol have been used for their possibly more rapid IOP-lowering 27. 9 Transluminal Nd:YAG laser embolysis when an occluding embolus is visible laser Embolectomy can be done The embolus is ejected into the vitreous via a hole in the arteriole. The main complication is vitreous haemorrhage. 10 Thrombolysis. Thrombolytic agents have been used for the treatment of CRAO route of admiration maybe local arterial (internal carotid and ophthalmic) or intravenous infusion. 28. Treatment of carotid disease In patients with a localized stenosis of the artery, endarterectomy significantly reduces the risk of subsequent stroke. In experienced hands this operation carries a mortality of less than 1%, although the incidence of morbidity is higher. If endarterectomy is contraindicated, medical treatment with drugs that reduce platelet stickiness (aspirin, dipyridamole) or anticoagulants may be used to reducing the frequency of transient ischaemic attacks and the risk of a major stroke. 29. Coming back to our patient Patient had presented 48 hours after occlusion and all ophthalmological investigations had been carried out.. He was informed of the poor visual prognosis. He was also informed about the possible life threatening complications and referred to a cardiologist 30. Take home message Do not treat if patient presents 48 hours after occlusion Treatment to salvage vision generally do not produce significant changes in the patient's vision dont take heroic measure These patients have a significantly reduced survival rate, and the main cause of mortality is cardiac. Therefore, prompt referral to a cardiologist is indicated. Central retinal artery occlusion may be caused by GCA; if undetected, the patient can develop severe, bilateral vision loss. Adoption of healthy life style may prevent CRAO 31. Words of wisdom from Prof Sohan Sing Hayreh CRAO..diagnosis is easy .. its management, however, remains highly uncertain and controversial 32. Thank you