Diabetic retinopathy is the name given to changes in the retina of the eye that can occur over a period of years in some people who have diabetes. It is potentially very serious. In diabetic retinopathy, the small blood vessels that nourish the retina (the light-sensitive tissue at the back of the eye) may begin to bulge, leak fluid, bleed, grow or block off and drop out. The disease follows no predictable course, and not all people with diabetes develop retinal changes. However the likelihood of developing retinopathy increases with the length of time a person has diabetes. Current research shows that careful control of diabetes, blood pressure, cholesterol/Lipids and early treatment of retinopathy improves the potential for avoiding impaired sight. It is very important that an eye specialist see every person with diabetes from time to time even if there are no visual symptoms to cause concern.
Types of Diabetic Retinopathy
- Background Retinopathy: This is the commonest form of diabetic retinopathy. In the early stages the tiny blood vessels in the retina swell and sometimes bulge. They may leak fluid and may begin to bleed within the retina. As long as only the outer retina is damaged, vision is not significantly affected.
If the damage causes leakage of fluid in the area of the macula, which is the part of the retina that gives the finest detail and recognises colour, then vision can be affected.
- Proliferative Retinopathy: This is a more advanced form of diabetic retinopathy and usually occurs when there has been diabetic damage to other parts of the body as well.
In proliferative retinopathy, small blood vessels in the retina cease to work and new blood vessels begin to grow from the surface of the retina. These new vessels are not healthy blood vessels and they are very fragile. They can easily break and may bleed. Vision will become cloudy and scar tissue may also form between the vitreous jelly and the retina. This tissue may contract and detach the retina from the back of the eye causing severe vision loss and in some cases blindness.
Treatment of Diabetic Retinopathy A regular eye examination every two years or so is essential for all people with diabetes, as early diagnosis and treatment improves the potential for avoiding vision-threatening changes to the eye. Even serious retinopathy can be present without symptoms and can improve with treatment. The interior of the eye may be photographed to provide more information about the blood vessels in the eye. Sometimes a special photo called a Fluorescein Angiogram is taken. Additionally an OCT may be performed.
- LASER: laser photocoagulation, a powerful beam of light is used to seal leaking blood vessels, destroy abnormal ones, and to prevent further formation of abnormal blood vessels. In the commonest (background) retinopathy, laser treatment HALVES the normal deterioration rate.
- Injection of anit vascular growth factors into the eye eg Avastin or Lucentis. Very effective especially when there is florid macular odema (fluid collection) that cannot be adequately treated by laser.
- Vitrectomy is a surgical procedure, which can remove blood and scar tissue from the vitreous and replace it with a clear solution.
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Other Eye Conditions Associated With Diabetes
- Cataract: Diabetes increases the possibility of cataract, which is a clouding of the transparent lens of the eye. If retinopathy has not damaged the retina then surgical removal of a cataract, to be replaced by an intra-ocular implant (a plastic lens), usually results in improved vision. Cataract surgery is sometimes not quite as successful in diabetic patients as in non-diabetic patients.