05/30/2025
CENTRAL RETINAL ARTERY OCCLUSION(CRAO) is an ophthalmologic emergency that occurs when the central retinal artery, the main blood vessel supplying the retina, becomes blocked. This results in sudden, painless vision loss in one eye.
🔍 ETIOLOGY (Causes)
★Embolism: Most common cause (from carotid artery or heart)
★Thrombosis
★Giant cell arteritis (in older adults)
★Hypercoagulable states
★Vasculitis (e.g., lupus)
★Trauma or iatrogenic causes (e.g., ocular surgery)
🧠 RISK FACTORS
★Atherosclerosis
★Hypertension
★Diabetes mellitus
★Carotid artery disease
★Cardiac disease (e.g., atrial fibrillation)
Smoking
★Hyperlipidemia
⚠️ CLINICAL FEATURES
★Sudden, painless monocular vision loss
★Afferent pupillary defect (Marcus Gunn pupil)
★Visual acuity often reduced to counting fingers or worse
🔬 FUNDOSCOPIC FINDINGS
★Retina appears pale and swollen
★Cherry-red spot at the fovea (due to preserved choroidal circulation)
★Boxcar segmentation of blood in arteries (sluggish flow)
★Attenuated arterioles
🧪 INVESTIGATIONS
★Ophthalmoscopy
★Fluorescein angiography
★ESR and CRP (to rule out giant cell arteritis)
★Carotid Doppler ultrasound
★Echocardiogram
★ECG
★Blood glucose, lipid profile, coagulation studies
🚑 MANAGEMENT (Emergency)
★Immediate action may help restore vision if done within 90–120 minutes, though prognosis is often poor.
★Ocular massage (to dislodge embolus)
★Anterior chamber paracentesis
Inhalation of carbogen (5% CO₂, 95% O₂)
★IOP-lowering agents: Acetazolamide, timolol, mannitol
★Hyperbaric oxygen (if available)
★Treat underlying systemic causes
🧾 Long-term Management
★Identify and treat underlying vascular or embolic sources
★Manage cardiovascular risk factors
★Antiplatelet or anticoagulation therapy as indicated
★Referral to cardiology and neurology
★Low vision rehabilitation if vision does not recover
📉 PROGNOSIS
★Poor in most cases
★Visual recovery depends on time to treatment and degree of collateral circulation
★Permanent vision loss is common if not treated promptly