Louis Clearkin
Tel: 0044 151 604 7047 L.Clearkin@liverpool.ac.uk

Retinal Vein Occlusion

Retinal vein occlusion is the blockage by thrombosis of the large central vein or a smaller branch vein.

This causes back-up pressure in the capillaries which, in the eye, leads to haemorrhage and fluid exudation into the retina. The extent or distribution of the haemorrhage depends on the occlusion site, ranging from a small branch vein causing a quadranic occlusion affecting a quarter of the retina, to a hemispheric (hemi-retinal) occlusion involving one half of the retina, to an occlusion of the central retinal vein, which involves the entire retina - a central retinal vein occlusion.

A severe large vein occlusion can lead to neovascular glaucoma, which untreated can lead to a severely painful blind eye in less than 12 weeks (see www.patient.co.uk/doctor/Central-Retinal-Vein-Occlusion.htm for more details). Timely anti-VEGF injections combined with laser photocoagulation of the retina reliably prevents this. Because of the potential severity of the condition, it requires urgent assessment with Optical Coherence Tomography (OCT), Fundus Fluorescein Angiography (FFA) and sometimes electro-diagnostic tests (see www.eyesurgery.com.au/index.php?id=visual for more details).

In some milder cases no treatment is needed except to address risk factors such as co-existing glaucoma, diabetes, a lipid problem or high blood pressure.

Where vision is compromised, Anti-VEGF injections (similar to the treatment of some types of AMD), possibly followed by laser photocoagulation will stabilise the condition - and in the current state of knowledge this is the best chance for improving vision. Both treatments are done on an outpatient basis.

Other treatments somtimes suggested include aspirin, surgery and infusion of thrombolytics but the evidence that any of these is effective is very doubtful, and to avoid any risks of side-effects, I rarely advise such treatments (see webeye.ophth.uiowa.edu/dept/crvo/09b.htm for more details).

To read the Royal College of Ophthalmologists guidelines on retinal vein occlusion, click here (download 99kb PDF).