Makindo Medical Notes

⚠️ Central Retinal Vein Occlusion (CRVO) is an ophthalmic emergency. 👁️ Patients must be urgently reviewed by ophthalmology to exclude other acute causes of visual loss and to guide management. Visual prognosis depends on the degree of ischaemia and complications such as macular oedema and neovascularisation.

About

• Venous outflow obstruction of the central retinal vein → retinal ischaemia & oedema.
• May occur due to thrombophilia or compression by adjacent arteriosclerotic artery.
• Common cause of painless monocular visual loss in older adults.

Aetiology

• Compression of vein by arteriosclerotic central retinal artery (shared adventitia at lamina cribrosa).
• Thrombus formation → stagnation of blood flow, venous congestion, ischaemia.
• Visual loss due to macular oedema or retinal neovascularisation.

Risk Factors (Arteriosclerotic & Haematological)

• 🩸 Hypertension, diabetes, hyperlipidaemia.
• 🚬 Smoking.
• 👁️ Glaucoma (raised intraocular pressure).
• 🧪 Hyperviscosity states: polycythaemia, multiple myeloma, Waldenström’s macroglobulinaemia, leukaemia.
• 💉 Thrombophilia, esp. in patients <50 yrs.
• Inflammatory eye disease (rare).

Clinical Presentation

• ⚡ Painless monocular loss of vision (may be sudden or progressive).
• Fundus findings:
  • “Blood and thunder” appearance → widespread flame-shaped haemorrhages.
  • Cotton wool spots, dilated & tortuous veins.
  • Macular oedema, swollen optic disc.
• History: ask about vascular risk factors, malignancy, personal/family history of DVT/PE.

Florid Haemorrhages and Dilated Veins

Differential Diagnosis

• Central retinal artery occlusion (CRAO).
• Retinal detachment.
• Migrainous aura with transient visual loss.
• Optic neuritis (esp. if painful visual loss).

Investigations

• 🧪 Bloods: FBC, ESR, U&E, glucose, lipid profile.
• ECG ± echocardiogram if cardiac risk factors.
• Thrombophilia screen if age <50 or no risk factors.
• OCT (optical coherence tomography) to assess macular oedema.
• Fluorescein angiography (ophthalmology) to grade ischaemic vs non-ischaemic CRVO.

Management

• 📉 Risk factor optimisation: treat hypertension, diabetes, lipids; smoking cessation.
• 💊 Consider low-dose Aspirin (75 mg OD) for vascular risk reduction.
• 👁️ Ophthalmology-directed:
  • Intravitreal anti-VEGF (e.g. ranibizumab, aflibercept) for macular oedema.
  • Intravitreal corticosteroids (e.g. dexamethasone implant) if VEGF unsuitable.
  • Laser photocoagulation if neovascularisation develops (to reduce risk of neovascular glaucoma).
• 🔎 Monitor for complications: rubeotic/neovascular glaucoma, vitreous haemorrhage, retinal detachment.

References

• RCOphth Guidelines – Retinal Vein Occlusion
• BNF Guidance