Diabetic retinopathy is a potentially blinding complication of diabetes affecting over half of Americans diagnosed with the disease. Fluctuations in blood sugar levels in diabetic patients lead to an increased risk for diabetic retinopathy. As a result of the body’s inability to use and store sugars, the tiny blood vessels that nourish the retina are affected. Damage to the retina, the light-sensitive tissue lining the back portion of the eye that transmits visual images to the brain, can result in severe loss of vision and ultimately blindness.
Background (Non Proliferative) Diabetic Retinopathy
In the early stages, vessels in the retina swell and begin to leak blood and fluid into surrounding tissue. This condition is called “Background diabetic retinopathy” or “Non proliferative diabetic retinopathy”. Vision is rarely affected during this stage. Later on, blurry or fluctuating vision will be noticed. Sometimes, spots, which are small specks of blood, appear in the field of vision. As the leakage progresses, blind spots can occur and the vision becomes cloudy. If left untreated, diabetic retinopathy can cause blindness.
Individuals who have been diagnosed with diabetes, or have a family history of the disease, should have their eyes examined on a regular basis. Diabetic retinopathy can be detected during a comprehensive eye examination. The health of the retina is checked with a special instrument called an ophthalmoscope. If any signs of diabetic retinopathy are detected, additional tests might be needed to assess the stage of the disease and determine treatment. The most commonly used test is Fluorescein Angiography also known as the dye test. A special dye is injected into the vein and pictures are taken from the retina, in the back of the eye. This test is used to assess the amount of leakage from the blood vessels, monitor progression and determine treatment.
When diabetic retinopathy is present and significant, laser is used to stop abnormal retinal blood vessels from leaking fluid and blood into the retina, especially the macula. This form of treatment is called Focal laser photocoagulation. Vision does not usually improve after laser treatment, but laser can frequently stop or slow further loss of vision.
Proliferative Diabetic Retinopathy
In the more advanced stages, new blood vessels begin to grow on the retina. These abnormal blood vessels are called neovascularization. The development of neovascularization is the retina’s attempt to compensate for the obstruction of its own blood vessels and the loss of nourishment. These abnormal and thin blood vessels have a tendency to bleed, resulting in a vitreous hemorrhage and the formation of scar tissue which can lead to permanent vision loss.
Intraocular injections of special medications known as “Vascular Endothelial Growth Factor (VEGF) Inhibitor”. These injections aim at shrinking the abnormal blood vessels and clear the bleeding.
Laser is also the main treatment for Proliferative Diabetic Retinopathy. This type of laser surgery is called panretinal laser photocoagulation (PRP). The laser is placed at the periphery of the retina and not in the center. After the treatment, the retina is likely to stop developing new blood vessels, and those that are already present tend to become inactive or even disappear.