AKT · Ophthalmology/Retina & vitreous

Central retinal vein occlusion

Thrombosis of the central retinal vein (hypertension, hyperviscosity, glaucoma)

Overview

Occlusion of the central retinal vein causing sudden, painless, variable monocular visual loss. The fundus shows widespread flame and dot-blot haemorrhages, dilated tortuous veins, cotton-wool spots and disc/macular oedema ('blood and thunder' / stormy-sunset fundus). Risk factors: hypertension, diabetes, hyperviscosity, glaucoma. Treated with anti-VEGF for macular oedema; watch for neovascular complications.

Recognise

Sudden painless blurring/loss of vision in one eye, usually less severe than CRAO and variable
Fundus: widespread retinal HAEMORRHAGES in all four quadrants, dilated tortuous veins, cotton-wool spots, optic-disc and macular oedema
Ischaemic CRVO (poor vision, RAPD, many cotton-wool spots) risks rubeosis → neovascular glaucoma

Red flags

Ischaemic CRVO → neovascularisation of the iris (rubeosis) and neovascular glaucoma at ~3 months ('100-day glaucoma') — needs panretinal photocoagulation
Bilateral CRVO/young patient → investigate hyperviscosity/thrombophilia

Differentials & how to tell them apart

Central retinal artery occlusionprofound sudden loss with a pale cherry-red-spot retina, not widespread haemorrhages

Branch retinal vein occlusionsectoral haemorrhages respecting the horizontal midline (at an AV crossing)

Diabetic retinopathybilateral, chronic, with microaneurysms/exudates rather than acute four-quadrant haemorrhage

Ocular ischaemic syndromecarotid disease, mid-peripheral haemorrhages with pain

CRVO — widespread 'blood and thunder' retinal haemorrhages
Werner JU, Böhm F, Lang GE / CC BY 4.0 — Wikimedia Commons

Investigations

Fundoscopy; OCT (macular oedema); fluorescein angiography (ischaemic vs non-ischaemic). BP, glucose/HbA1c, lipids, IOP; hyperviscosity screen if young/bilateral.

Management

Refer; anti-VEGF for macular oedema + treat vascular risk factors

1Refer to ophthalmology. Treat the macular oedema (intravitreal anti-VEGF first-line, or steroid implant) and manage vascular risk factors (BP, diabetes, lipids, IOP).Gate: Identify ISCHAEMIC CRVO (poor vision, RAPD, extensive non-perfusion) — it risks rubeosis and neovascular glaucoma, requiring monitoring ± panretinal photocoagulation
2Neovascular complications → panretinal photocoagulation; lifelong vascular risk management; investigate young/bilateral cases for thrombophilia/hyperviscosity.

Intravitreal anti-VEGF (e.g. ranibizumab/aflibercept) — first-line for macular oedema reducing vision

Intravitreal steroid (dexamethasone implant) — alternative for macular oedema

Treat vascular risk factors — BP, diabetes, lipids; manage raised IOP/glaucoma

Key points

Sudden painless monocular blur + 'blood and thunder' four-quadrant haemorrhages = CRVO. The danger downstream is neovascular glaucoma — distinguish ischaemic from non-ischaemic.

Monitor & prognosis

Serial OCT/visual acuity; monitor for neovascularisation.

Variable; non-ischaemic better than ischaemic.

Source: RCOphth Retinal vein occlusion guidelines