Diabetic retinopathy is a progressive and potentially blinding disease which results from damage to the small blood vessels that nourish your retina, the part of your eye that captures light and sends it to your brain to be turned into pictures. In the early stages, the eye’s blood vessels break and leak fluid and blood into the retina which causes swelling, also known as edema. Later, damage blocks blood flow to the retina and, because blood vessels carry oxygen to the eye, your retinal function and vision get worse. Eventually new, but weak, blood vessels grow but rupture, causing more damage in a phase called proliferative diabetic retinopathy. The new blood vessels can also bleed easily into the gel-filled, or vitreous, cavity of your eye. Furthermore, scar tissue tends to form along with the new blood vessels which can pull on and detach the retina.
Why am I at risk of retinopathy just because of my diabetes?
High glucose levels caused by diabetes weaken blood vessels throughout your body, including in your eyes.
Is there anything I can do to prevent getting this condition?
The best way to minimize diabetic retinopathy damage is to maintain good glucose control, as well as normal blood pressure and lipid levels.
What are the symptoms of diabetic retinopathy?
Early on, there may be none. But over time, moderate damage to the retina can cause several types of vision loss. The central spot in the retina, called the macula, is designed for accurate and detailed vision such as reading. It is very small—the diameter of the inside of a Cheerio cereal hole. Leaking blood vessels leads to swelling, called macular edema, which can cause blurred vision or small blind spots. Because gravity affects the swelling you may notice these symptoms more in the morning, after lying down all night. They may diminish when you have been up and around for a while. If the disease progresses to a stage called proliferative diabetic retinopathy, and your eye hemorrhages you may experience floaters, sheets or veils which interrupt your vision.
How will I know I have it?
In the early stages, you may not be aware, as there are no symptoms. It is important, therefore, for people with diabetes to see an ophthalmologist on a regular basis. If you experience any blurred vision or blind spots, see a doctor as soon as possible.
What are the best ways to manage diabetic retinopathy if I get it?
You must strive to control your glucose, lipid, and blood pressure numbers. This may slow the onset or progression of diabetic retinopathy, but there are effective, proven treatments, especially in the early stages. Laser photocoagulation can reduce swelling of your macula. Newer treatments also include injections of corticosteroids or anti-vascular endothelial growth factor (anti-VEGF) therapy. To reduce swelling, this drug neutralizes a retinal molecule that causes both blood vessel leakage and the formation of very weak new vessels. Proliferative diabetic retinopathy, when severe, requires extensive laser treatment known as pan retinal laser photocoagulation. To control formation of these new but weak blood vessels, the doctor targets the peripheral regions of the retina with a laser. If the retina detaches from the back of your eye, or blood clouds the vitreous, you may need a vitrectomy to clear the eye or repair scar tissue.
What else should I know about diabetes and my eyes?
The best way to prevent vision loss is to control your blood glucose, blood pressure and cholesterol, and to have regular eye exams by an ophthalmologist.
Dr. James T. Handa is a Professor in the Retina Division at the Wilmer Eye Institute of the Johns Hopkins University School of Medicine, Baltimore, Maryland. He specializes in medical and surgical management of Vitreoretinal diseases such as Age-related macular degeneration, Diabetic retinopathy, Retinal detachment, Retinopathy of Prematurity, and other pediatric retinal diseases. He also sees ocular oncology patients.