Central Retinal Vein Occlusion (CRVO)

Features

•    Sudden, painless, unilateral vision loss

•    Fundoscopy: "blood and thunder" appearance

o    Dilated, tortuous veins

o    Retinal haemorrhages

o    Cotton wool spots

o    Optic disc oedema

Risk factors

•    Hypertension

•    Diabetes

•    Glaucoma

•    Hyperviscosity states (e.g., polycythaemia vera)

Management

•    Intravitreal anti-VEGF (e.g., ranibizumab)

•    Laser photocoagulation (if neovascularisation)

Central Retinal Artery Occlusion (CRAO)

Features

•    Sudden, profound, painless monocular vision loss

•    Fundoscopy: pale retina with cherry-red spot at fovea

Causes

•    Embolus (e.g., carotid plaque, cardiac source)

•    Giant cell arteritis (elderly)

Management

•    Emergency → poor prognosis

•    Ocular massage, acetazolamide to reduce IOP

•    Consider temporal artery biopsy & steroids if GCA suspected

Hypertensive Retinopathy

Grade    Findings

1            Arteriolar narrowing ("silver/copper wiring")

2            AV nicking

3            Cotton wool spots, haemorrhages, exudates

4            Papilloedema