Diabetic retinopathy is the name given to the collection of problems of the retina (nerve layer) of the eye which are directly caused by damage from diabetes. This condition can affect patients with any form of diabetes mellitus. Over time, chronic damage of the small blood vessels of the retina can cause diabetic retinopathy to form, which is of two main types.
Non-proliferative diabetic retinopathy (NPDR) is the earlier stage of diabetic retinopathy, and in this stage, the small blood vessels of the retina leak blood and fluid – when this fluid enters the center of a patient’s retina, the macula, macular edema is said to be present. Because macular edema swells the retina at its most important spot for vision, a patient’s vision will be affected when it develops. A much more severe complication of diabetic retinopathy can occur later – the capillaries (small blood vessels) of the retina may close off due to the degree of damage sustained from diabetes. Unfortunately, this change is a permanent one and their closure results in a loss of blood supply to the retina and these affected areas of the retina then die – when this occurs in the center of vision, this is known as macular ischemia.
Proliferative diabetic retinopathy (PDR) occurs when regions of the retina become damaged by the closing off of capillaries. In response, the eye will start to grow new blood vessels in an attempt to provide blood flow to the damaged areas of the retina. Unfortunately, these blood vessels are of a very poor quality and bring with them fibrous tissue. These new blood vessels, or neovascularizations, are prone to frequent and sometimes profound bleeding, which can obscure the vision through clouds of actual blood which can be large enough to block almost all vision in the affected eye. Even worse, if permitted to grow unchecked, these new blood vessel clusters can produce an intense scarring and cause a type of retinal detachment to occur (one which is often difficult to treat), which will lead to vision loss.
Regular screening eye examinations are very important for all diabetic patients to ensure that they are not suffering from diabetic retinopathy. Earlier stages of the disease process may produce little to no symptoms and will not be detected without an eye exam. The best form of protection against this condition is early detection, so yearly review is recommended. As important as maintaining regular follow-up with all involved health care providers, is the maintenance of good control of blood sugar. More severe forms of diabetic retinopathy and/or complications which arise from this condition do require a more stringent follow-up schedule to ensure the best possible outcomes for vision.
Treatment options for patients with diabetic retinopathy range from observation, to macular laser photocoagulation (office-based laser surgery), to subthreshold laser photocoagulation (office-based Micropulse laser surgery), to intravitreal injections with anti-VEGF agents or steroids (injection with liquid medication into the eye), to panretinal photocoagulation (office-based laser surgery).