Diabetic retinopathy is damage to the retina (the tissue responsible for providing vision) due to complications of diabetes. If left untreated and ignored, this condition can lead to blindness. The longer a person has had diabetes, the more likely they are to have diabetic retinopathy, and often patients aren’t aware that the problem exists until damage has already been done. Diabetic retinopathy affects up to 80 percent of people with diabetes who have had the condition for more than 10 years. At this time, diabetic retinopathy is the leading cause of blindness in persons between 20 and 64 years of age! With proper treatment of diabetes, and monitoring of the eyes, 90% of these cases can be reduced.
In the first stage of diabetic retinopathy, there are generally no symptoms. Patients can have perfectly normal 20/20 vision, and not be aware that anything is going wrong. This first stage is called non-proliferative diabetic retinopathy (NPDR), and the only way to detect NPDR is by having regular eye exams from an eye care professional such as an optometrist or ophthalmologist. During this exam, the doctor can detect if there is any bleeding or swelling in the back of the eye. The American Diabetes Association recommends for this reason that any patient who has a diagnosis of diabetes should have a dilated eye exam at least once a year. During the second stage of diabetic retinopathy, abnormal new blood vessels grow (neovascularisation) around the areas where there was bleeding from NPDR. This second stage is called proliferative diabetic retinopathy (PDR). The new blood vessels are very fragile and they can burst and bleed, causing floaters and blurred vision. If the condition is still not treated, there can be a greater leakage of blood which interferes with eyesight. In final stages, the retina can become detached, or permenantly damaged which leads to blindness.
Macular edema is a condition which may occur at any stage of the disease. Macular edema is swelling in the central part of the retina and vision. It can cause blurring, darkening or distorted images in one or both eyes.
Individual Risk Factors Both patients who have Type I and Type II diabetes can develop diabetic retinopathy. The risk of retinopathy and the severity of the retinopathy tends to be worse when a patient has had diabetes for a longer period of time. Because Type I diabetes often is diagnosed at a younger age, patients with Type I diabetes often have more severe retinopathy at a younger age. Diabetic retinopathy can become significantly worse during pregnancy. For that reason, all pregnant diabetic women should have a dilated eye examination each trimester to ensure their vision remains healthy.
Treatment: There are four main treatment options which are effective in reducing vision loss from this disease. Even people with advanced retinopathy have a 90 percent chance of keeping their vision when they get treatment before the retina is severely damaged. The only way that a doctor can detect if you have retinopathy and give you the appropriate treatment is if you have the recommended yearly eye examination.
Treatment 1 – Laser Treatment This can be used to either treat macular edema or for early stages of proliferative retinopathy. During the procedure, an ophthalmologist will dilate the pupil and applies numbing drops to the eye. The patient sits in front of the laser machine while the doctor holds a special lens on the eye. During the procedure, the patient will see flashes of light, which can create an uncomfortable stinging sensation. The vision will most likely remain blurry for a few hours afterwards, however there should not be much pain in the eye itself—other than a mild to moderate headache like pain which may last for hours afterwards.
Patients lose some of their peripheral vision, color vision, and night vision after this surgery, though it may barely be noticeable by the patient. The goal of the procedure does is to save the center of the patient’s sight. There is a possibility that multiple treatments may be necessary to preserve a patient’s vision.
Treatment 2 – Intravitreal Triamcinolone Injection Triamcinolone is a long acting steroid which can decrease the swelling cuased by diabetic maculopathy, which can result in improved vision. When injected in the vitreous cavity, it decreases the macular edema (thickening of the retina at the macula) caused due to diabetic maculopathy, which typically results in an increase in visual acuity. The effect is temporary and can last up to three months, and then the injection may need to be repeated. Because this steroid can result in early cataracts, the best results of injected Triamcinolone have been found in eyes that have already undergone cataract surgery. Other complications of intravitreal triamcinolone injection include steroid-induced glaucoma and endophthalmitis.
Treatment 3 – Intravitreal Anti-VEGF Injection Another class of medicines that can be used in a similar way to decrease swelling and control the development of new, fragile, and unneeded blood vessels are the Anti-VEGF medicines. These can be injected in the same way that Triamcinolone is injected, and have shown very good results. Your doctor will be the best person to determine which treatment option is best for you.
Treatment 4 – Vitrectomy Some patients require a surgical procedure called a vitrectomy to restore vision. A vitrectomy is typically performed when there blood in the vitreous which limits a person’s vision, or when there is so much damage to the retina that it requires immediate repair. It involves removing the clear central jelly in the eye and replacing it with a saline solution. Having a vitrectomy early in the course of retinal compromise is especially effective in people with insulin-dependent diabetes, and studies have shown that people who have a vitrectomy soon after a large internal bleed are the most likely to preserve their vision compared to someone who waits. During a surgical vitrectomy, a small incision is made in the sclera (the white of the eye) and a small instrument is placed into the eye to remove the vitreous gel, and replace it with saline solution. After the operation, the eye will be red and sensitive, and patients usually need to protect the eye with an eyepatch or shield. Antibiotic eye drops are also used to decrease inflammation and protect against infections.
Preventative Measures Controlling high blood pressure and avoiding tobacco use are very important measures to aid in managing diabetic retinopathy. One of the most important ways to prevent and control the complications of diabetic retinopathy is to keep the blood sugars under the best control possible.