If you have diabetes, your body does not use and store sugar properly. High blood sugar levels can damage blood vessels in the retina, the nerve layer at the back of the eye that senses light and helps to send images to the brain. This damage to the blood vessels is referred to as diabetic retinopathy.
There are two types of diabetic retinopathy: Nonproliferative Diabetic Retinopathy (NPDR) and Proliferative Diabetic Retinopathy (PDR).
NPDR is an early stage of diabetic retinopathy. Tiny blood vessels within the retina leak blood and fluid and this can cause the retina to swell or form deposits called exudates. If the macular area of the retina is affected, macular edema and/ or macular ischemia can result.
- Macular Edema is swelling or thickening of the macula, a small area in the center of the retina that allows us to see fine details. Vision loss may be mild to severe
- Macular Ischemia occurs when small blood vessels close. Vision blurs because the macula no longer receives adequate blood supply
PDR is present when abnormal, new vessels (neovascularization) begin growing on the surface of the retina or optic nerve. Widespread closure of blood vessels cause this pathology. The retina responds by growing new, abnormal blood vessels but these vessels do not supply the retina with normal blood flow. Scar tissue that may cause wrinkling of the retina or retinal detachment can occur.
- Vitreous Hemorrhage occurs when the fragile, new, abnormal blood vessels bleed into the vitreous; this may cause partial or complete loss of vision. It may take days, months, or years for this blood to reabsorb. A surgical procedure to remove the blood may be needed.
- Traction retinal detachment may also occur as a result of scarring
- Neovascular glaucoma may also occur as the abnormal, new blood vessels grow on the iris (the colored part of the eye) and block the normal flow of fluids out of the eye
Treatment of NPDR and PDR:
Laser Surgery - Laser surgery is often recommended for people with macular edema, PDR, and neovascular glaucoma. The main goal of this treatment is to prevent further loss of vision. The laser treatments are highly individualized and planned according to the patient's specific pathology. Multiple laser treatments may be necessary. This is not a cure but a means to preserve vision.
Vitrectomy - In advanced PDR, a vitrectomy may be recommended. The procedure will clear the vitreous space of any blood and hopefully preserve the vision. Often, vitrectomy prevents further bleeding.
In Summary: Vision loss if you have diabetes is often preventable. With today's improved methods of diagnosis and treatment early evaluation is important in preserving vision in diabetics.
People who have diabetes should be evaluated at least once yearly by an Ophthalmologist. Any visual changes should be evaluated by an Ophthalmologist as soon as possible in a diabetic. Diabetics must maintain a stable blood glucose as well as have regular Ophthalmologic care to preserve their vision.