A. Diabetes and vision Diabetes affects tiny blood vessels that nourish the retina, the eye’s internal projection screen. Over time, the retinal blood vessels become clogged or leak. When the retina?s blood vessels are unable to deliver enough nutrients to its light-sensitive cells, vision loss occurs. This disease is called diabetic retinopathy.
In the early stages, tiny blood vessels in the retina become blocked or damaged, cutting off the food supply to small patches of light-sensitive cells. Blood (hemorrhage) or fluid (exudate) leaks into retinal tissues, causing swelling. At first, sight is rarely affected. For that reason, this stage is called background retinopathy.
Over time, abnormal blood vessels grow into the retina and vitreous (jelly-like substance that fills the eye) in places where tiny blood vessels no longer function. These rogue vessels are fragile and rupture easily. When leaks occur, complications can cause severe vision loss if not promptly treated. This advanced stage of disease is called proliferative retinopathy.
When abnormal vessels burst, blood or fluid can collect in the retina’s central spot or macula. This spot is responsible for central vision. When it is swollen, central vision gets blurry. Fine details are lost. Reading, watching television and driving become difficult. If not treated promptly, macular edema may cause permanent vision loss.
As the body works to repair damage to the retina, scars form. Eventually, scar tissue can push the retina away from the back of the eye (retinal detachment). This detachment causes permanent loss of vision. If caught early, laser surgery may prevent or limit irreversible vision loss.
When abnormal vessels bleed into the vitreous, vision is blurred. Specks of blood may float through your field of vision. Large leaks into the vitreous can obscure sight, making it difficult to tell light from dark. The blood may clear away in a few days, months or even years. Large leaks (hemorrhages) often occur during sleep. If a lot of blood builds up in the vitreous, the eye doctor may recommend a vitrectomy. This operation replaces the cloudy vitreous with a clear solution.
Timely treatment of problems, macular edema, retinal detachment, abnormal blood vessel formation or blood- clouded vitreous, may prevent or limit permanent loss of vision in people with diabetes.