About Diabetic Retinopathy

Diabetic Retinopathy is the eye disease that is a complication of systemic Diabetic Mellitus. While many patients with diabetes believe that the principle problem is an inability to effectively use glucose, the effects of diabetes are more extensive and really effect many organs and tissues throughout the body. Diabetes is actually characterized as a disease that damages the blood vessels throughout the body and impairs the normal circulation of blood in the body. It is quite common for patients with diabetes to experience difficulty with the circulation in their legs, kidneys, heart, brain and eyes-especially the very small blood vessels of the eye found in the retina. When diabetes causes damage to the small blood vessels in the retina, it is called Diabetic Retinopathy.

Normally, the blood vessels in the retina are well lined and do not leak. One of the earliest effects of diabetes is to cause the blood vessels to begin to leak by weakening the inner lining of the blood vessels so that they become porous. Leakage from the retinal blood vessels causes the center of the retina to actually swell, a condition called diabetic macular edema.  As this swelling usually occurs in the macula, or the area responsible for central vision, macular edema results in vision loss of varying degrees. The most effective way to observe and make a proper diagnosis of macular edema is perform and Intravenous Fluorescein Angiogram ( IVF ).The Intravenous Fluorescein Angiogram is performed in the office at D’Ambrosio Eye Care by first injecting a special fluorescent dye into a vein in the patients’ arm and then taking a series of photographs of the retina as the dye circulates throughout its blood vessels. In this way it is possible to accurately and directly observe the circulation and the integrity of the blood vessels in the retina. This diagnostic test allows the eye physician to assess the severity and location of “leaky” blood vessels. It is important that leaking blood vessels be found as early as possible so that they can be most effectively sealed with a laser treatment. In most cases, early laser treatment will reduce the swelling and prevent further vision loss. In some cases, patients can have macular edema but still maintain normal vision. However, any diagnosis of macular edema is an indication that breakdown of the retinal blood vessels from diabetes is starting to occur and requires careful monitoring.

Diabetic Retinopathy is a progressive process. As diabetic retinopathy begins to progress, the retinal blood vessels continue to weaken and begin to narrow and close. As the blood vessels close, they can no longer carry oxygen to the retinal tissue. This results in a condition called Retinal Ischemia. Retinal ischemia is characterized by the retina being deprived of sufficient oxygen and nutrients to maintain normal health and functioning. Typically, the retina responds to ischemia by attempting to compensate for the reduced circulation by growing new, but abnormal blood vessels-a process called neovascularization. The condition whereby retinal neovascularization exists is called proliferative diabetic retinopathy.

While new blood vessel growth or neovascularization might seem like a beneficial event, these new blood vessels are extremely fragile and tend to break easy and hemorrhage. If left untreated, proliferative diabetic retinopathy will in fact result in hemorrhage that leads to scarring and ultimately to retinal detachment with profound vision loss. Proliferative diabetic retinopathy is treated with either laser treatment or laser treatment in conjunction with a surgical procedure called a vitrectomy. The retinal surgeon will perform a vitrectomy in order to remove the vitreous that has become filled with blood or scar tissue. Sometimes it may be possible for patients to have proliferative diabetic retinopathy and neovascularization and yet still have good vision. It is critical that in order to maintain that good vision the neovascularization be treated as quickly as possible even if it does appear to be causing any vision loss.

Patients with diabetes must be diligent and attentive to their eye care throughout their lives. To preserve vision and attempt to avoid the complications of diabetic retinopathy, it is important for diabetic patients to have a comprehensive eye exam at least once a year to detect bllod vessel leakage and the presence of diabetic retinopathy in its earliest stages. While “screening photographs”, even through a dilated pupil may be of some use, it is not a substitute for a comprehensive diabetic eye examination by an eye doctor. Diabetic patients may also be more prone to other significant eye problems such as glaucoma and cataracts and thus a comprehensive eye examination is a necessity. Depending on the severity and progression of diabetic retinopathy, it might be necessary to have an Intravenous Fluorescein Angiogram (IVF) on a regular basis in order to observe and record any changes to the retinal circulation. In general, most insurance carriers endorse and pay for regular annual diabetic eye exams with Intravenous Fluorescein Angiography as often as needed in order to help patients preserve vision. High quality diabetic eye care is an important event for all diabetic patients.

The American Diabetic Association (ADA) recommends yearly eye examinations for all diabetic patients. Further, current research indicates that even patients who are glucose intolerant, but do not have a definitive diagnosis of diabetes are at risk of developing diabetic retinopathy and thus should have annual eye exams. It is likely that in the future we will see the ADA recommendations modified to take this research into account.

Today, we know that all diabetics need to have regular eye exams because with  the early and aggressive treatment of diabetic retinopathy it is possible to maintain vision and prevent severe vision loss form many patients. The National Institutes of Health and the National Eye Institute have funded large scale, multi-center, controlled studies, such as the Early Treatment of Diabetic Retinopathy Study (ETDRS) that have produced treatment guidelines indicating which patients may benefit from laser treatments to preserve vision and delay progression of vision loss. These studies demonstrated that with early treatment it is possible for patients with diabetic retinopathy to have only half the likelihood of losing vision as compared to those patients who failed to receive early treatment.

Diabetes and General Health

Maintaining good health is quite important for diabetic patients. In particular controlling blood sugar levels helps to protect the circulation in the heart, kidneys and eyes. Any and all risk factors for vascular disease should be carefully managed. These include controlling high blood pressure, not smoking, exercising regularly, reducing dietary fat intake and lowering cholesterol and triglycerides. Be sure to fully comply with all of your physicians’ directions and advice. If you have been diagnosed with diabetes or even if you glucose intolerant, you should have a thorough diabetic eye examination at D’Ambrosio Eye Care. Our eye doctors will provide a thorough eye examination, consultation and answer all of your questions about diabetic eye problems.