What is a Retinal Vein Occlusion?
Retinal Vein Occlusions in older patients are usually the result of high blood pressure, high cholesterol, diabetes and smoking. These conditions are the same ones that increase the risks of a stroke or a heart attack. In younger patients, they may be due to the same risk factors as above, but we would also consider investigating for causes of thickening of the blood, which may contribute to the blockage. When the blood flow along a retinal vein is blocked, the pressure builds up in the smaller blood vessels behind, and they bleed into the retina. Vein occlusions can occur all over the retina, known as Central Retinal Vein Occlusions, or CRVO, or just in one or two segments, known as Branch Retinal Vein Occlusion.
Questions I usually ask
· Are you having difficulty seeing the TV screen clearly or reading subtitles?
· Are you struggling to recognize bus numbers or people’s faces until they are really close?
· Is it difficult reading small print unless the lighting is really bright?
· Do you feel that your glasses aren’t giving you clear vision, and your optician has said that
they can’t improve with a new prescription?
· Do you have hazy vision?
· Is it difficult to see clearly when you are driving?
· Do you have glare with night driving or in bright lights (such as supermarket lighting)?
· Are you having difficulty reading music?
· Is your vision affecting your work?
· Do have a particular hobby or interest that your vision is affecting?
If you are a driver and your vision does not meet the DVLA standards for driving (read a number plate from 20m, see Driving Eyesight Rules) I will usually recommend cataract surgery if you wish to continue driving. In milder cases you can see your optician first because a change in glasses or contact lenses may improve the vision to legal driving standards for a year or two, but you will need to keep checking to be sure you are legal for driving. You need to be able to read a number plate made after 2001 at 20m in daylight with your glasses or contact lenses if you use them. Your visual acuity must be 6/12 or better and you need an adequate field of vision.