Diabetes Mellitus is a disease in which the ability of the body to produce and/or use insulin is abnormal resulting in high levels of blood sugar (serum glucose). This causes damage throughout the body including the eyes. High blood sugar damages blood vessels in the retina which is the nerve layer in the back of the eye which is responsible for sensing light and transmitting images to the brain. Damage to the retinal vessels is called diabetic retinopathy (DR).

​

There are two types of diabetic retinopathy:  nonproliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR).  Nonproliferative diabetic retinopathy is an earlier stage of diabetic retinopathy.  The damaged blood vessels leak blood or fluid into the retina.  The vision can be affected when the retina swells (macular edema) or there is loss of blood supply to the retina (macular ischemia).

Proliferative Diabetic Retinopathy occurs when abnormal blood vessels begin to form due to a poor blood supply to the retina.  These are not normal vessels and can lead to vision loss through vitreous hemorrhage or retinal detachment.  Sometimes, glaucoma can result from abnormal blood vessel growth in the front of the eye.  

The best treatment for diabetic retinopathy is prevention through good control of blood sugar.  High blood pressure and kidney disease should also be controlled.  If diabetic retinopathy does develop and requires treatment, injections, laser, or surgery can be performed to help preserve vision.  

It is important that patients with diabetes mellitus see an ophthalmologist regularly.  Patients with type 1 diabetes should be examined within five years of their diagnosis and then yearly.  Patients with type 2 diabetes should have an examination at the time of diagnosis and then yearly.  Pregnant women with diabetes should be seen within the first trimester because retinopathy can progress rapidly during pregnancy.  

It is important to know that early detection of diabetic retinopathy is the best protection against vision loss.  You can lower your risk of vision loss by maintaining strict control of your blood sugar and blood pressure and seeing your ophthalmologist regularly.