Retinal Vein and Artery Occlusions
Retinal Vein Occlusions
A central retinal vein occlusion (CRVO) occurs when there is an obstruction of the outflow of blood from the eye back to the systemic circulation. This result in engorgement (dilation) of the retinal veins, and wide-spread intraretinal haemorrhages. CRVO usually results in sudden painless loss of vision in one eye. There is often associated swelling of the macula, the central part of the vision, known as macular oedema.
A branch retinal vein occlusion (BRVO) occurs when there is a blockage to the returning blood supply of only one main branch of the retina. Patients who present with features of a BRVO or CRVO need careful evaluation to determine the best management strategy. This consists of a complete dilated ophthalmic examination, as well as optical coherence tomography (OCT). Fundus fluorescein angiography (FFA) is needed to assess for retinal ischaemia.
Provided there is not significant macular ischaemia, macular oedema from a CRVO or BRVO can be treated with intravitreal injection therapy. Argon retinal laser may be required to treat areas of peripheral retinal ischaemia.
Retinal Artery Occlusions
A retinal artery occlusion can occur due to a blockage of the main artery supplying blood to the eye, known as a central retinal artery occlusion (CRAO). Alternatively there may be a blockage of only one major retinal division, known as a branch retinal artery occlusion (BRAO). Similar to a vein occlusion, retinal artery occlusions usually present as sudden painless loss of vision in one eye.
There are several techniques that can be attempted in patients with a CRAO to reduce the risk of severe vision loss, provided the patient presents within a short time-window after the onset of symptoms.
Several important underlying medical conditions need to be considered to identify the cause of the obstruction, and these treated as necessary. Our specialists will discuss this with you in detail if required, and answer any questions you may have. Laser treatment may be required to reduce the risk of neovascular glaucoma developing, resulting in a painful eye due to high intra-ocular pressure.