Diabetes Mellitus is a systemic disease in which the body either does not produce enough insulin or does not respond appropriately to the insulin that it does produce. As a result, the blood sugar (glucose) level becomes too high. When a person experiences high glucose levels for extended periods, changes in multiple organ systems in the body may occur. Among these are changes in the eyes.
Diabetes can affect virtually every aspect of the ocular structures. These changes can be acute and short-lived, or gradual and progressive. There are several categories of diabetic retinopathy:
Non-proliferative diabetic retinopathy typically has no symptoms. This stage of retinopathy is best detected on examination of the retina by an ophthalmologist. Typical findings include:
Swelling of the center of vision, macular edema, is caused by leakage from blood vessels. Symptoms may include blurred vision and distorted images.
microaneurysms (microscopic blood-filled bulges in the artery walls).
Proliferative retinopathy in which new blood vessels (neovascularisation) form in the back of the eye. These abnormal blood vessels can bleed (vitreous hemorrhage) and blur the vision due to their fragility. These vessels can also lead to traction retinal detachments.
Many of these manifestations can be treated with laser photocoagulation or the administration of medications into the eye that reduce abnormal blood vessel growth.