Diabetes has damaging effects on blood vessels throughout the body. When the blood vessels in the retina become damaged, they may leak fluid, bleed or lead to the growth of scar tissue. All of these changes can cause blurring, distortion, loss of detail vision, floaters and blindness.
Diabetic retinopathy is the leading cause of new blindness in adults in the United States. However, with early diagnosis and treatment only a small percentage of people who develop diabetic retinopathy will go on to develop severe vision loss.
What are the different types of diabetic retinopathy?
This is an early form of the disease, and it is also the most common. Elevated blood sugars damage the blood vessels within the retina causing them to bleed or leak fluid into the retina, causing swelling. The blood vessels also leak cholesterol-like material, called exudates, into the surrounding retina. When the swelling occurs in the macula, the center part of the retina, this can cause changes in the central vision. This is called macular edema.
This is a severe and vision-threatening form of the disease. Vessels damaged by high blood sugars result in poor blood flow and can not supply oxygen to the retina. In response, the retina grows new blood vessels to replace the damaged ones. This process is called neovascularization. Unfortunately, these new blood vessels grow abnormally. They can break and bleed easily (vitreous hemorrhage) or they can form scar tissue which can distort the retina and may even cause the retina to detach. A retinal detachment is a serious complication, and often requires surgery. Sometimes, the abnormal blood vessels can grow in the front of the eye which can lead to a dangerous rise in the pressure within the eye, which is a known as neovascular glaucoma.
How is diabetic retinopathy diagnosed?
Retinopathy, particularly at its earliest stages may not produce any visual symptoms. Early detection is the best way to prevent vision loss. Therefore, it is crucial for all patients with diabetes to undergo a complete eye exam by an ophthalmologist, with careful evaluation of the retina at least once a year and more frequently once diabetic retinopathy is detected.
How is diabetic retinopathy treated?
Treatment depends primarily upon the type and severity of the retinopathy. The most important aspect of treatment, however, is prevention. By regularly monitoring blood sugar, and maintaining a healthy program of diet and exercise, you can significantly reduce your chances of developing retinopathy.
Laser is performed by directing a beam of light into the eye to treat the damaged parts of the retina. In cases of background diabetic retinopathy with macular edema, the laser is used to seal off leaking blood vessels and to stimulate the eye to reabsorb the fluid. When abnormal blood vessel growth is present, as in proliferative diabetic retinopathy, laser is used to decrease and prevent blood vessel growth. Laser surgery is often performed in the office and usually only requires topical or local anesthesia. Multiple laser treatments are often necessary.
Bleeding into the vitreous cavity can occur in severe cases of proliferative diabetic retinopathy. If the vitreous is filled with blood, surgery may be recommended to remove the blood from the center of the eye and the abnormal vessels causing the bleeding. Even though the blood may be severely impairing your vision, your doctor may advise waiting to see if the blood clears on its own before recommending surgery. Vitrectomy surgery is also performed to repair retinal detachments caused by excessive scar tissue that develops in proliferative retinopathy.