Diabetic Retinopathy
What It Is, Types, Diagnosis, and Treatment
If you have diabetes mellitus, your body does not use and store sugar properly. The sugars stay in your blood since it can’t be taken up as well by your body’s cells. The high blood sugars damage the blood vessels throughout your body, including your eyes. When the vessels in the retina are damaged, it is called ‘diabetic retinopathy’.
Types of Diabetic Retinopathy
Nonproliferative diabetic retinopathy (NPDR) is an early stage of diabetic retinopathy. In this stage, tiny blood vessels within the retina leak blood or fluid. The leakage causes the retina to swell or to form deposits called exudates.
In the early stages of mild diabetic retinopathy vision remains unaffected. As the retinopathy worsens vision can be affected by macular edema (swelling in the macula) affecting the center of the vision. As it continues to worsen, macular ischemia may occur as the vessels close. Vision blurs because the macula doesn’t receive adequate blood flow to work properly. This can cause permanent vision loss.
Proliferative diabetic retinopathy is present when more and more vessels in the retina close and prevent adequate blood flow. The eye responds by growing abnormal new vessels on the retina or optic nerve. Unfortunately the new abnormal vessels do not resupply the retina. Instead they can bleed inside of the eye (vitreous hemorrhage) which may take months to clear. Sometimes the bleeding is so significant and clears so slowly that surgery is required to remove the blood.
Scarring may occur with the abnormal vessels. This can cause the retina to wrinkle or detach (tractional retinal detachment).
Occasionally, the disease may affect the front of the eye by causing abnormal new vessels to grow on the iris. This causes the drainage angle to close and results in neovascular glaucoma. This is a severe type of glaucoma that causes damage to the optic nerve.
How Is Diabetic Retinopathy Diagnosed?
A dilated eye exam is the best way to detect changes in your eye. If macular edema or ischemia is suspected, an OCT may be done to determine the extent of the disease.
How Is Diabetic Retinopathy Treated?
The best treatment is to prevent the development of retinopathy by having strict control of your blood sugar. This significantly reduces the long term vision loss from diabetic retinopathy. Early on, regular yearly eye exams may be all that is required.
Once the disease progresses you may need to be seen more frequently. If macular edema starts to threaten your vision, intravitreal injections or laser may be done. Laser surgery is also used to treat proliferative diabetic retinopathy or neovascular glaucoma. A vitrectomy may be required for advanced proliferative diabetic retinopathy.