What is Diabetic Retinopathy?
Diabetes is a disease in which patients have abnormal blood sugar levels. This abnormal blood sugar level then affects blood vessels through out their body. In Diabetic Retinopathy (DR), the retinal blood vessels are damaged. Diabetic retinopathy can occur in patients with Type I or Type II diabetes.
Patient with diabetes lose vision from diabetic retinopathy for multiple reasons: diabetic macular edema, proliferative diabetic retinopathy and poor perfusion of the retina due to lack of blood flow (ischemia).
Diabetic Macula Edema (DME):
When blood vessels are damaged in diabetic retinopathy it may result in abnormal leakage of fluid and blood into the retina; this leakage can cause the retina to swell. When this leakage occurs in the macula, the area of the retina responsible for our central vision, it is called Diabetic Macular Edema (DME). This then leads to a decrease in vision and is also the most common cause of visual loss in patients with diabetes.
Proliferative Diabetic Retinopathy (PDR):
Diabetic retinopathy is graded based on the degree of abnormal blood vessels that are created by the eye in response to a lack of normal blood flow. In Non-Proliferative Diabetic Retinopathy (NPDR) or Background Diabetic Retinopathy (BDR), your doctor will see the initial stages of diabetic retinopathy but no abnormal blood vessel growth. Proliferative Diabetic Retinopathy (PDR) occurs when abnormal blood vessels grow within and on top of the retina. These abnormal blood vessels are called "neo-vascularization" and they are fragile and can bleed into the eye causing a Vitreous Hemorrhage. If this occurs you may notice a sudden onset of many dark floaters or it may cause immediate dramatic loss of vision. In advanced cases the blood vessels can lead to scar tissue pulling and contracting on the retinal surface and lead to a Tractional Retinal Detachment, where the retina is pulled away from the back of the eye leading to loss of vision.
What is the treatment for Diabetic Retinopathy?
Prevention is always the most important treatment in patients with diabetes. It is crucially important to follow up with your medical doctor and maintain tight blood sugar control.
Once diabetic retinopathy has been diagnosed it may be medically treated with the use of injections of medicine into the eye (Intravitreal Injections) or laser treatment, or a combination of both depending on your doctors findings. Recent science has shown that diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) are controlled by a distress signal sent from the damaged retina called Vascular Endothelial Growth Factor (VEGF). Thus when, one of several VEGF blocking drugs (including Avastin, Lucentis, and Eylea) or other medications (steroids and steroid implants) are injected into the eye, they can cause DME and PDR to regress. These treatments typically, however, only provide temporary relief and need to be given repeatedly over a prolonged period of time.
In some instances laser treatment may be recommended for people with DME, PDR, or severe NPDR. The goal of treatment is to prevent further loss of vision. The laser is applied to the damaged or distressed retina to decrease the abnormal blood vessels and prevent them from growing. Often times multiple laser treatments are necessary. This also is not a curative procedure and does not always prevent further loss of vision.
In advanced cases of diabetic retinopathy surgical treatment is needed. Vitrectomy (surgical removal of the vitreous) may be recommended if bleeding from the abnormal blood vessels caused by the diabetic retinopathy fills the eye cavity. This is called a Vitreous hemorrhage and is associated sudden and typically dramatic loss of vision. In other severe cases, surgery may be needed to repair a tractional retinal detachment
It is very important to understand that good blood sugar control and early diagnosis and treatment can significantly reduce the progression and risk of severe visual loss. Diabetes is a disease which requires close cooperation between the primary care physician, eye doctor and patient. It has been shown in large studies that tight blood sugar, blood pressure, cholesterol and weight control can reduce the long-term risk of vision loss from diabetic retinopathy. Your primary care physician plays a key role in the medical management and coordination of your care. Early detection of diabetic retinopathy allows the best chance for maintaining good vision throughout your life.