What is Diabetic Retinopathy?
Diabetic retinopathy (DR) is a leading cause of severe and permanent blindness in people with diabetes which arise as a complication of diabetes. As DR is can be asymptomatic until very advanced stages, you may not notice any change in your vision until it has become quite severe.
Risk factors & Complications
Having diabetes for many years and poor diabetic control are both important risk factor for developing diabetic retinopathy. It is important to control blood sugar levels well by maintaining a healthy diet with regular exercise. This is even more crucial if you have had diabetes for a long time.
Pregnancy may also cause more difficulty sugar control in diabetics or even precipitate gestational diabetes. This can cause diabetic retinopathy to develop or worsen pre-existing diabetic retinopathy.
During the earlier stages, small blood spots appear in the retina which your eye doctor will be able to see on dilated eye examination. As DR worsens over time, fragile abnormal blood vessels start to grow in the eye. In the retina, these vessels can break easily and leak blood into the vitreous gel of the eye, obscuring vision. In the front of the eye, these abnormal vessels grow into the drainage angles of the eye and can cause a secondary glaucoma and a painful blind eye.
Another common cause of vision loss in diabetics is macula edema or swelling. This is a process when fluid leaks out of leaky vessels at the macula and accumulate there, causing blurring of the central vision. If untreated, this results in irreversible loss of vision.
One other serious complication of untreated DR, is the formation of scar tissue on the retina. This can cause traction on the retina, causing severe retinal detachments.
Prevention is better than cure. Therefore, annual eye screening for diabetic retinopathy in diabetics with good sugar control is crucial in picking up any developing DR early, before blinding complications develop. Screening should be done more frequently in newly diagnosed diabetics, in patients whose blood sugar control is not optimal, or in pregnant women with diabetes.
Good sugar control is the most crucial step in treating diabetic retinopathy. This can be achieved by having regular meals, a healthy diet, and regular exercise. Controlling other chronic medical conditions like high blood pressure and high cholesterol is important as well.
Diabetic retinopathy itself is usually treated with argon laser to the retina known as panretinal photocoagulation. This helps prevent the growth of the abnormal fragile vessels. Nowadays, we can also perform injections of anti-VEGF agents into the back cavity of the eye, known as intravitreal injections.
Macular edema, on the other hand, is primarily treated with intravitreal anti-VEGF therapy. We may sometimes also do argon laser as an adjunctive therapy and in certain patients, intravitreal injections of steroids can also be used to treat the swelling.