Gradual Loss of Vision
Persons with diabetes who experience any change in vision must see an eye doctor right away. Diabetes patients can help protect their sight by having an eye exam at least once each year. Diabetic patients who are pregnant should have their eyes examined once each trimester.
You Can Protect Your Eyesight
The amount of damage suffered by the retina from diabetic retinopathy depends on how long the patient has suffered from diabetes. Severe retinopathy and blindness are seen in patients with long-standing disease. Retinal damage usually occurs from a lack of oxygen delivered to the tissues when the tiny blood vessels in the area break down as a result of diabetes. Diabetic patients who have high blood pressure, increased fat in the blood, or who smoke are at higher risk for eye and blood vessel disease and are more likely to develop retinopathy.
Stages and Symptoms: Diabetic retinopathy is a painless condition, and it can progress without the patient knowing it unless eye examinations are performed annually. Diabetic retinopathy begins when chronic diabetes causes damage to the tiny blood vessels in the retina. This is a slow process, and there are usually no symptoms during this early stage. When the damaged blood vessels begin to bleed and leak fluid and fat into the macula (part of the retina that controls detailed vision), some patients may notice blurry vision. Although the blood and fluid may be absorbed by the retina, scar tissue can form and affect vision. As the damage to the retina progresses, new blood vessels are formed on the surface of the retina and even in the vitreous humor, a jelly-like material in the back of the eye. However, these new vessels are fragile, can easily break and bleed, and can lead to the detachment of the retina. Retinal detachment is a medical emergency, and requires immediate attention to avoid a complete and permanent loss of vision. Retinal detachment is a painless condition with symptoms of blurred vision, flashing lights, floaters, or a shadow over part of the visual field.
Diagnosis: Patients diagnosed with diabetes, whether they are taking insulin or oral medications, should have their eyes examined when they are first diagnosed and then each year thereafter. Early retinopathy can be diagnosed during an examination by an ophthalmologist using an ophthalmoscope. The bright light of this instrument, shining through a dilated eye, allows the examining physician to see any changes in the retina, such as dilated blood vessels or tiny areas of bleeding. A dye may be injected into a vein in the arm to detect blood vessels in the retina that are leaking. Using a series of photographs during this angiography procedure, the physician can focus on areas in the retina that have bled or are likely to bleed.
Treatment: Laser photocoagulation helps to protect vision by treating the damage that has already occurred so it will not result in further damage. It does not cure retinopathy. Laser photocoagulation can be limited to certain areas (known as “spot treatment”) or across the entire retina (known as “pan retinal treatment”). In more serious cases of retinopathy, laser treatment may include full retinal treatment as well as spot treatments near the macula. If retinopathy has progressed to the formation of new, fragile blood vessels that have bled into the vitreous, vitrectomy surgery is used to help save vision. This surgery removes the cloudy vitreous humor and replaces the fluid with a salt solution, through which vision is clear again. Laser photocoagulation is performed under local anesthesia in the doctor’s office; vitrectomy may require an overnight hospital stay. Your pharmacist can help plan a blood sugar control program to prevent potential retinal damage.