Retinal vein occlusion occurs when the circulation of a retinal vein becomes obstructed by an adjacent blood vessel, causing haemorrhages in the retina. Swelling and ischaemia (lack of oxygen) of the retina as well as glaucoma are fairly common complications.
The visual symptoms can vary in severity from one person to the next, and are dependent on whether the central retinal vein or a branch retinal vein is involved. Patients who experience a branch vein occlusion often notice a gradual improvement in their vision as the haemorrhage resolves. Recovery from a central vein occlusion is much less likely since it affects the macula.
This problem appears equally in males and females and is more common after the age of 60.
|Normal Retina.||Retinal Vein Occulsion.|
Signs and Symptoms
- Sudden onset
- Blurred ormissing area of vision (if a branch vein is involved)
- Severe loss ofcentral vision (if a central vein is involved)
Detection and Diagnosis
Vein occlusion is diagnosed by examining the retina with an ophthalmoscope. Fluorescein angiography may be performed in some cases to study the circulation of the retina and to determine the extent of macular oedema or swelling.
Following a vein occlusion, the primary concern is to treat the secondary complications.If areas of the retina are oxygen-deprived, LASER may be used to prevent growth of delicate vessels that could break, bleed or cause glaucoma.
The following are common risk factors for vein occlusion:
- Cardiovascular disease
Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.