Laser retinopathy surgery uses laser burns to stop blood vessels bleeding into and growing over the retina, the part of the eye that responds to light. A common indication for laser retinopathy surgery is a condition known as proliferative retinopathy, which develops in people with diabetes. In proliferative retinopathy, fragile, leaky blood vessels grow inside the eye and across the retina, with a risk of sight loss. Laser retinopathy surgery may also be indicated to treat another condition associated with diabetes, known as macular edema. In macular edema, fluid leaks from abnormal blood vessels in the eye and causes swelling in the macula, the part of the retina responsible for sharp vision.
Diabetes is a disease in which blood sugar levels become abnormally high, with effects throughout the body. In the eyes, diabetic retinopathy can occur, where blood vessels in the retina become swollen, leading to bursting and leaking. This is the first stage of the condition, known as mild nonproliferative retinopathy. It is followed by a moderate stage, in which some blood vessels become blocked, and a severe stage, where so many vessels are blocked that the retina's blood supply becomes inadequate. The retina begins to grow new blood vessels in the final stage, known as proliferative retinopathy, and it is this stage which requires laser retinopathy surgery.
There may not be any symptoms at any stage of retinopathy, or there may be visual changes, with dark patches appearing in the field of view. Eye examinations are required to detect the condition and monitor its progress. If proliferative retinopathy develops, the type of laser retinopathy surgery used to treat it is known as scatter laser treatment. During this kind of laser eye surgery, thousands of tiny burns are made in the retina. This helps to discourage the growth of new blood vessels and also scars existing fragile vessels, preventing them from bleeding.
Macular edema can develop at any of the stages of diabetic retinopathy. It may not cause any symptoms, but can cause loss of vision if left untreated. The type of laser retinopathy surgery used to treat macular edema is known as focal laser treatment. Hundreds of laser burns are made in areas of the retina where fluid is leaking. This helps to stop the leakage and reduce swelling.
Both types of laser retinopathy surgery may require more than one session before treatment is successful. Although eye surgery cannot restore sight which has been lost, it can prevent vision deteriorating in most cases. Having regular eye examinations gives the best chance that diabetic retinopathy and macular edema can be diagnosed and treated as soon as possible, before sight loss occurs.