Dr Amy Cohn Ophthalmic Surgeon

A Central Retinal Vein Occlusion (CRVO) occurs when the main vein that drains blood away from the retina becomes blocked. The severity varies but usually results in retinal haemorrhages, macular oedema, macular ischaemia and occasionally new blood vessel growth on the iris at the front of the eye.

Patients usually present with loss of vision in the affected eye. Occasionally the presentation is with a painful type of glaucoma called neo-vascular glaucoma.

CRVOs are commonly associated with diabetes, and possibly high blood pressure, high cholesterol and glaucoma.

Your Ophthalmologist can diagnose a CRVO by examining the back of the eye. Occasionally a fluorescein angiogram is performed. This is where dye is injected into a vein in your arm and photographs are taken over a 10 minute period to identify new vessels and the areas of blockage. In addition, an OCT may be performed to check for macular oedema.

Laser therapy is thought not to be helpful in treating macular oedema from CRVOs.

Newer treatments include intra-vitreal injections. This is where drugs such as Avastin®, Lucentis® (ranibizumab), Eylea® (aflibercept) or a steroid is injected into the back of the eye. This is usually done in the doctor’s rooms and is generally well tolerated.

Often multiple injections are required to stabilise the vision as the duration of action of the drug is only 4-6 weeks.

There is no treatment for macular ischaemia.

If new vessels are seen on the iris urgent pan-retinal laser is required to prevent a painful type of glaucoma called neo-vascular glaucoma. Patients with new vessels usually do not know they have them. Like with focal laser the eye is anaesthetised with drops and a contact lens is placed on the eye to view the retina. Multiple laser spots are put onto the retina to cause regression of the new vessels.