Retinal eye disease

DR. ANGANA SHAH

Learn more about retinal eye diseases

Diabetic Eye Disease >

Age-Related Macular Degeneration >

Written by: Dr. Angana Shah, board-certified eye physician and fellowship-trained retinal surgeon

Diabetic Eye Disease

What is Diabetic Eye Disease?

Diabetes is a disease that affects children and adults. It occurs when the pancreas does not secrete enough insulin, or the body is unable to process it properly. Insulin is the hormone that regulates the level of sugar (glucose) in the blood.

When you have diabetes, your body doesn't use sugar (glucose) properly. If your blood sugar level is too high or too low, your eye’s natural lens may swell intermittently- which can result in blurry vision. Too much sugar in your blood also damages the tiny blood vessels in your body (capillaries) and in the retina over time. This leads to diabetic retinopathy, or damage to the retina. Diabetic retinopathy makes the blood vessels leaky and causes retinal bleeding and swelling leading to decreased vision. In advanced stages, poor blood flow and lack of oxygen signal the growth of abnormal new blood vessels in the retina. The body is trying desperately to get oxygen to the retina, but these vessels are weak. This progresses to scarring and retinal detachment. Finally, this can result in blindness.

Signs of diabetic retinopathy

Some of the common signs and symptoms of diabetic retinopathy include blurred vision (due to swelling), floaters (due to bleeding and hemorrhages inside the eye), and a gradual or sudden loss of vision. Diabetics also tend to develop cataracts earlier. Cataracts can further lead to a decrease in vision by creating cloudiness within the natural lens of the eye. There may also be a greater risk of glaucoma (increased eye pressure and damage to the optic nerve within the eye) in patients with diabetes.

Who's at risk?

All people with diabetes-both type 1 and type 2. It's essential that every diabetic patient get a thorough, comprehensive, dilated eye exam annually because a person can have significant retinopathy, requiring treatment, with no symptoms at all. Approximately half of all diabetics have some form of retinopathy. The risks greatly increase the longer you have the disease with almost 90% of patients having signs of eye disease after 10 years of living with diabetes.

Treatment options

Treatment for diabetic retinopathy will depend on its severity. Typically, laser treatment of the retina has shown good success in treating the abnormal growth and leakage of blood vessels. Surgery to remove blood and scar tissue from bleeding vessels can also help in severe cases. Newer medications, which are injected directly into the eye can help control bleeding vessels. An ophthalmologist or a retinal specialist, who specializes in retinal laser treatment and surgery for diabetics, can guide you through the best and most effective treatment for your eyes after a careful examination.

The best treatment, of course, is prevention. Well-controlled blood sugar and annual eye exams to screen for any early signs of the disease are important.

Well-controlled blood pressure is also important, since the combination of poor blood sugar and blood pressure control can be devastating to the eye. Most diabetic patients are frequently examined by an internist or endocrinologist who, in turn, should work closely with an ophthalmologist to manage the eye disease.

Age-Related Macular Degeneration

Age-related macular degeneration (ARMD or AMD) is an eye disease that affects central vision. It specifically targets the macula, which is the central portion of the retina. If you think of your eye like a camera, the retina is like the film. It receives light and then sends a message through your optic nerve to the brain, where it interprets these signals into the images you see.

There are two forms of AMD, dry and wet. In dry AMD there is damage and thinning of the layer just under the retina. These areas cannot absorb light, which creates blind spots. Dry AMD usually progresses slowly over time.

In wet AMD, blood vessels grow through these weak areas like weeds through cracks in the sidewalk. These abnormal blood vessels then bleed and cause swelling, which distorts the retina and, in turn, your vision. Unfortunately, this change can occur overnight. About 10% of those with AMD have the wet form.

Who’s at risk?

AMD affects over 13 million people in the United States. As the name implies, the older a person, is the higher their risk of AMD. Other risk factors include family history, light colored eyes, Caucasian race, female gender, smoking, heart disease, and obesity. Sun exposure and low nutritional diet have also been indicated as risks.

What are the signs of AMD?

In AMD, deterioration of retinal cells leads to blind spots or distortion of the central vision. This makes it difficult to read or recognize faces in late stages. In its early stages there may be little or no symptoms, which is why it’s important to have regular dilated eye exams every year after the age of 50. Check your eyes daily by covering one at a time to make sure there is no vision loss. You should see an eye doctor immediately if you are seeing things that as angled or crooked.

AMD treatments

At this time there is no cure for AMD, but there are treatments that can help slow it down. A large study by the National Eye Institute called the Age-Related Eye Disease Study (AREDS) proved that antioxidant vitamins can slow the progression of dry AMD and decrease the risk of developing the wet form. The study recommends Vit A 28,640 IU, Vit C 452mg, Vit E 400 IU, Zinc 69.6 mg and Copper 1.6 mg. Only individuals considered to be high risk by their eye doctor should be on this regimen, since these dosages are much higher than the normal daily recommended amounts. Most doctors also recommend a healthy diet including plenty of green vegetables, oily fish like salmon, and certain nuts.

Many patients with wet AMD have positive results through special infections in the eye(s). These injections block one of the hormones called vasoendothelial growth factor (VEGF) which helps the abnormal blood vessels grow and leak fluid. The injections are performed by an ophthalmologist or retinal specialist. the injections are typically repeated every 4 to 6 weeks, until the swelling and bleeding stops. In a majority of patients, vision improves if treated promptly.

Another treatment option for wet AMD is with hot or cold lasers. Usually, laser treatments are combined with anti-VEGF injections or used if injections fail.

There is a lot of research being done on AMD. Hopefully, advanced medical options like gene therapy can be used prevent the deterioration of the macula. As the general population of the world ages, this research and new treatment options will become more and more important to helping preserve sight in those affected.