WHAT IS PROLIFERATIVE DIABETIC RETINOPATHY?
Proliferative diabetic retinopathy is an advanced form of diabetic eye damage and is caused by longstanding high blood sugars. The hallmark of this advanced form of diabetic retinopathy is the development of abnormal new retinal blood vessels, a process termed neovascularization. With diabetes, the smaller blood vessels tend to clot off over time, leading to the growth of new vessels that proliferate on the surface of the retina. Unfortunately, these new vessels are fragile and bleed easily. When we diagnose a patient with proliferative diabetic retinopathy, we are seeing these abnormally fragile vessels beginning to grow in irregular sheets across the back of the eye. These abnormal blood vessels often bleed and encourage the development of scar tissue.
HOW DO THESE ABNORMAL BLOOD VESSELS CAUSE EYE DAMAGE?
Neovascular vessels, the abnormal blood vessels that grow in proliferative diabetic retinopathy, can bleed abruptly into the middle of the eye, causing a vitreous hemorrhage. Additionally, neovascularization produces scar tissue, which can pull the retina off the interior wall of the eye, creating a situation known as a tractional retinal detachment. New blood vessels may grow on the iris, or the colored part of the front of the eye leading to a painful and blinding rise in eyepressure known as neovascular glaucoma.
HOW IS THE DIAGNOSIS OF PROLIFERATIVE DIABETIC RETINOPATHY MADE?
The first step is a careful eye exam where both pupils are dilated. If new blood vessel growth is suspected, you may need a special test called a fluorescein angiogram. This is a photographic study of the back of the eye performed after an orange-colored dye is injected in a vein in the hand or arm. The dye circulates through the body into the eye to highlight abnormal vessels, or where treatment is needed. If the eye is too filled with blood to examine, your doctor can perform a quick and painless evaluation of the eye’s internal structure with sound waves. This kind of "sonar" for the eye is called an ocular ultrasound.
HOW IS PROLIFERATIVE DIABETIC RETINOPATHY TREATED?
Laser photocoagulation is one of the most common treatments for diabetic retinopathy. In this kind of surgery, brief spots of bright light are scattered through the sides of the retina to reduce abnormal blood vessel growth and help seal the retina to the back of the eye. It is a proven way to prevent bleeding and retinal detachment. Laser surgery may need to be repeated several times. If you have very advanced proliferative diabetic retinopathy, a vitreous hemorrhage that will not clear on its own, or a retinal detachment, your doctor may recommend a surgery called a vitrectomy. During a vitrectomy, the surgeon removes the blood-filled vitreous and replaces it with clear salt water, clearing the way for additional laser treatment. A vitrectomy is performed in the hospital or outpatient surgery center with anesthesia. The surgeon will use a special microscope to look into your eye, and will perform the procedure using microsurgical instruments.