Diabetics are at increased risk of developing eye disease, including diabetic retinopathy, cataracts and glaucoma. The most common of these is diabetic retinopathy, the leading cause of new cases of blindness among working-age people in the United States. If you have diabetes, you are likely to get cataracts at a younger age and your chances of developing glaucoma are doubled.
Diabetic retinopathy is a potentially vision threatening condition in which the blood vessels inside the retina become damaged from the high blood sugar levels associated with diabetes. In some people with diabetic retinopathy, blood vessels may swell and leak fluid. In other people, abnormal new blood vessels grow on the surface of the retina. The longer you have diabetes, the greater your chance of developing diabetic retinopathy. The risk increases if blood sugar levels and blood pressure are poorly controlled.
Once diagnosed with diabetes, schedule a comprehensive dilated eye evaluation at least once a year. Your eye doctor will recommend more frequent examinations if abnormalities are detected. Diabetic eye disease is most successfully treated if it is diagnosed early, before vision is significantly affected. Because there are often no symptoms in the early stages of diabetic retinopathy, your vision may not be affected until the disease becomes severe.
You should also see your ophthalmologist promptly if you experience:
- Blurred vision that last more than a few days
- Blurred vision that is not associated with a change in blood sugar
Women with diabetes should also be examined if considering pregnancy, early in the first trimester and every 1 to 3 months during pregnancy because diabetic retinopathy can progress much more rapidly during pregnancy.
An effective partnership between you, your primary care physician and your Eye M.D. is essential to assure proper eye care and treatment.
The current primary treatment option for diabetic retinopathy is an office treatment called laser photocoagulation. With the “pan retinal” laser, the ophthalmologist makes tiny burns on the retina surface removing damaged retinal tissue. This helps to stop or prevent growth of abnormal blood vessels that cause vitreous hemorrhage and retinal detachment. The “focal” laser helps to close leaking blood vessels, which lead to macular edema. When performed promptly, laser photocoagulation helps reduce the risk of severe vision loss by up to 90 percent.
Recent studies show that intensive control of diabetes with self-monitoring of blood sugar levels can significantly slow the development of diabetic retinopathy and other complications from diabetes. As always, early diagnosis of diabetes and the effective control of blood sugar levels and hypertension through diet, exercise, and medication can help control eye diseases associated with diabetes.
Dry AMD occurs when the light-sensitive cells in the macula slowly break down, gradually blurring central vision in the affected eye. As dry AMD gets worse, you may see a blurred spot in the center of your vision. Over time, as less of the macula functions, central vision is gradually lost in the affected eye. The most common symptom of dry AMD is slightly blurred central vision. You may have difficulty recognizing faces. You may need more light for reading and other tasks. Dry AMD generally affects both eyes, but vision loss may be more severe in one eye than the other.
During your comprehensive dilated eye exam, your ophthalmologist examines the macula for signs of AMD. In mild cases this may be seen as a mild disturbance in the normal pigment layer which is underneath the macula. In some cases, drusen develop. Drusen are yellow deposits under the retina. They often are found in people over age 60. Drusen alone do not usually cause vision loss. In fact, scientists are unclear about the connection between drusen and AMD. They do know that an increase in the size or number of drusen raises a person’s risk of developing either advanced dry AMD or wet AMD. These changes can cause serious vision loss. Dry AMD has three stages, all of which may occur in one or both eyes:
- Early AMD. People with early AMD have either several small drusen or a few medium-sized drusen. At this stage, there are no symptoms and no vision loss.
- Intermediate AMD. People with intermediate AMD have either many medium-sized drusen or one or more large drusen. Some people see a blurred spot in the center of their vision. More light may be needed for reading and other tasks.
- Advanced Dry AMD. In addition to drusen, people with advanced dry AMD have a breakdown of light-sensitive cells and supporting tissue in the central retinal area. This breakdown can cause a blurred spot in the center of your vision. Over time, the blurred spot may get bigger and darker, taking more of your central vision. You may have difficulty reading or recognizing faces until they are very close to you.
If you have vision loss from dry AMD in one eye only, you may not notice any changes in your overall vision. With the other eye seeing clearly, you still can drive, read, and see fine details. You may notice changes in your vision only if AMD affects both eyes. Ninety percent of all people with AMD have dry AMD. The Cause is not known
Wet AMD is the more rapidly progressing form of AMD. Generally it occurs in people with prior signs of dry AMD. In wet AMD abnormal blood vessels form behind the retina and start to grow under the macula. These new blood vessels tend to be very fragile and often leak blood and fluid. The blood and fluid separate the macula from its normal position in the back of the eye. With wet AMD, loss of central vision can occur quickly. Wet AMD is less common than dry AMD, but more commonly leads to severe central vision loss. An early symptom of wet AMD is that straight lines appear wavy. If you notice this condition or other changes to your vision, contact your eye care professional immediately.
Risk factors for AMD include age. Although AMD may occur during middle age, studies show that people over age 60 are clearly at greater risk than other age groups. Other risk factors include:
- Smoking. Smoking may increase the risk of AMD.
- Obesity. Research studies suggest a link between obesity and the progression of early and intermediate stage AMD to advanced AMD.
- Race. Whites are much more likely to lose vision from AMD than African Americans.
- Family history. Those with immediate family members who have AMD are at a higher risk of developing the disease.
- Gender. Women appear to be at greater risk than men.
Treatment for wet AMD includes laser surgery, photodynamic therapy, and injections into the eye. None of these treatments is a cure for wet AMD. The disease and loss of vision may progress despite treatment.
Wet AMD can now be treated with new drugs that are injected into the eye (anti-VEGF therapy). Abnormally high levels of a growth factor called VEGF occur in eyes with wet AMD and promote the growth of abnormal new blood vessels. This drug treatment blocks the effects of the growth factor. You will need multiple injections that may be given as often as monthly. The eye is numbed before each injection. After the injection, you will remain in the doctor’s office for a while and your eye will be monitored. This drug treatment can help slow down vision loss from AMD and in some cases improve sight. Medications include Macugen, Avastin, and Lucentis.
There is no treatment for advanced dry AMD. However, treatment can delay and possibly prevent intermediate AMD from progressing to the advanced stage, in which vision loss occurs. However, the National Eye Institute’s Age-related Eye Disease (AREDS) study found that taking a specific high-dose formulation of antioxidants and zinc significantly reduces the risk of advanced AMD and its associated vision loss. Slowing AMD’s progression from the intermediate stage to the advanced stage will save the vision of many people. People who are at high risk for developing advanced AMD should consider taking the formulation. You are at high risk for developing advanced AMD if you have either:
-Intermediate AMD in one or both eyes.
-Advanced AMD (dry or wet) in one eye but not the other eye.
Your ophthalmologist can tell you if you have AMD, its stage, and your risk for developing the advanced form.
The AREDS formulation is not a cure for AMD. It will not restore vision already lost from the disease. However, it may delay the onset of advanced AMD. It may help people who are at high risk for developing advanced AMD keep their vision.
If you are already taking daily multivitamins and your doctor suggests you take the high-dose AREDS formulation, be sure to review all your vitamin supplements with your doctor before you begin. Because multivitamins contain many important vitamins not found in the AREDS formulation, you may want to take a multivitamin along with the AREDS formulation.
If you have dry AMD, you should have a comprehensive dilated eye exam at least once a year. Your ophthalmologist can monitor your condition and check for other eye diseases. Also, if you have intermediate AMD in one or both eyes, or advanced AMD in one eye only, your doctor may suggest that you take the AREDS formulation containing the high levels of antioxidants and zinc.
Because dry AMD can turn into wet AMD at any time, you should get an Amsler grid from your ophthalmologist. Use the grid every day to evaluate your vision for signs of wet AMD. This quick test works best for people who still have good central vision. Check each eye separately. Cover one eye and look at the grid. Then cover your other eye and look at the grid. If you detect any changes in the appearance of this grid or in your everyday vision while reading the newspaper or watching television, get a comprehensive dilated eye exam.
If you have wet AMD and your doctor advises treatment, do not wait. After any treatment, you will need frequent eye exams to detect any recurrence of leaking blood vessels. Studies show that people who smoke have a greater risk of recurrence than those who don’t. In addition, check your vision at home with the Amsler grid. If you detect any changes, schedule an eye exam immediately.