How Diabetes Affects Your Vision
Diabetes is a disease in which the body's ability to regulate blood sugar becomes impaired. When blood sugar is out of control, your lens swells, causing nearsightedness. Changing your eyeglass prescription during periods of poor glucose control is generally not recommended because this condition is usually temporary.
Diabetes also increases your risk of developing serious vision problems including cataracts, glaucoma, diabetic retinopathy, and double vision.
Diabetic Retinopathy results from damage to the blood vessels that supply the retina. It is the leading cause of visual loss in adults age 20 to 64 years of age, and afflicts approximately 90 percent of patients who have had diabetes for 15 years or more. Juvenile diabetics are especially prone to the disease at an early age. The condition may be aggravated by pregnancy or high blood pressure. Fortunately, most visual loss can be prevented with regular eye examinations and early treatment.
Types of Diabetic Retinopathy
Background retinopathy, an early stage of the condition (Fig. 1) involves changes in the blood vessels within the retina. Some shrink, others grow, to form balloon-like sacs which may leak or hemorrhage. In the majority of cases, sight is not seriously affected. However, this is a warning sign that a sight-endangering condition could occur in the future, so more frequent eye exams are required to monitor for further deterioration.
Diabetic macular edema (Fig. 2 & 3) is a more serious form of diabetic retinopathy. Fluid accumulates in the macula, the center portion of the retina which may cause distortion and even loss of central vision.
Proliferative diabetic retinopathy (fig. 4) is the most severe stage and the most threatening to sight. It is caused by a lack of oxygen to the eye, which stimulates abnormal blood vessel growth. These vessels are fragile and may rupture. Scar tissue from the ruptured blood vessels may tighten and pull on the retina, detaching it from the inner wall. There is no symptom of pain, and severe loss of sight, even blindness, may result.
Examination & Diagnosis
The best way to prevent visual loss is through regular dilated eye examinations. Yearly eye exams are recommended for diabetics over the age of thirty. If you are pregnant, you should see your eye doctor at least once during the first 3 months of pregnancy. If you are younger than thirty years old, you should have an annual exam starting five years after diabetes is diagnosed. If there is evidence of damage to your eye, however, more frequent exams may be necessary.
Specialized equipment can be used to examine your eye. If there is evidence of diabetic retinopathy, a fluorescein angiography may be required. During this test, fluorescent dye is injected into the bloodstream and photographs of the blood vessel system in the retina are taken. These are used to evaluate the condition of the blood vessels and serve as a "road map" for laser treatment.
When diabetic retinopathy is detected early, in-office laser treatment is typically used to arrest the damage. Lasers are used to seal and reduce leaking blood vessels in patients with diabetic macular edema (Fig. 2 & 3). Laser treatment also is used for patients with proliferative diabetic retinopathy to halt abnormal blood vessel growth (Fig. 4).
In severe cases of proliferative diabetic retinopathy, bleeding occurs in the vitreous--the gel-like substance in the center of the eye. In some instances it clears naturally and no further treatment is necessary. However, if it does not clear, a vitrectomy--surgical removal of the cloudy material --may be advised.
The best way to prevent the development of diabetic retinopathy is to keep your blood sugar and blood pressure under control. Regular check ups with your medical doctor, a dietician, and a diabetic consultant are the best way to control your diabetes.
Successful treatment of diabetic eye conditions depends greatly on your willingness to participate fully in your care. Regular eye exams are critical in maintaining vision. It is much easier to prevent visual loss from diabetes, than restore sight after it is lost. If you notice any reduction in vision, or a large number of new floaters, schedule an evaluation with Madison Eye Associates immediately.