Stages of Diabetic Retinopathy
Stages of Diabetic Retinopathy
Diabetic Retinopathy tends to appear and progress in Stages (http://www.nei.nih.gov/health/diabetic/retinopathy.asp) beginning with Mild Nonproliferative, progressing to Moderate Nonproliferative Retinopathy, further advancing to Severe Nonproliferative Retinopathy and without proper attention developing into the most severe stage, Proliferative Retinopathy.
Mild Nonproliferative Retinopathy
Mild Nonproliferative Retinopathy is the earliest stage of Diabetic Retinopathy. It is characterized by the presence of “dot” and “blot” hemorrhages and “microaneurysms” in the Retina during your eye examination. Microaneurysms are areas of balloon like swelling of the tiny blood vessels in the Retina caused by the weakening of their structure. Mild Nonproliferative Retinopathy can be present without any change in your vision. Mild Nonproliferative Retinopathy usually does not require treatment unless it progresses or if is accompanied by Diabetic Macular Edema. If you have Mild Nonproliferative Retinopathy, Dr. Whitaker will make specific recommendations about how often you will need to be reexamined and whether any additional testing might be required.
Moderate Nonproliferative Retinopathy
Moderate Nonproliferative Retinopathy is the second and slightly more severe stage of Diabetic Retinopathy. During this stage, some of the small blood vessels in the Retina may actually become blocked. The blockage of these tiny blood vessels causes a decrease in the supply of nutrients and oxygen to certain areas of the Retina.
In order for Dr. Whitaker to properly diagnose blockage of the small blood vessels in the Retina it may be necessary to have a diagnostic test called a Fluorescein Angiogram (FA) or Intravenous Fluorescein Angiogram (IVFA). Dr. Whitaker performs Fluorescein Angiography right in our office at Riverside Eye Center in Norway, Maine.
Prior to starting your Intravenous Fluorescein Angiogram drops will be placed in your eyes to dilate your pupils. Next, Dr. Whitaker will inject a fluorescent dye, called Sodium Fluorescein into a vein in your arm. After approximately 15 seconds the dye will begin to circulate throughout the retinal blood vessels. Using a specialized retinal camera, a series of photographs of the Retina are taken to study the circulation of blood through the retinal blood vessels. Using the IVFA, it is possible for Dr. Whitaker to observe the circulation and the integrity of the blood vessels in the Retina so that he can identify any blood vessels that might be blocked.
Severe Nonproliferative Retinopathy
Severe Nonproliferative Retinopathy is the next stage of Diabetic Retinopathy. Severe Nonproliferative Retinopathy is characterized by a significant number of small blood vessels in the Retina actually becoming blocked. As more blood vessels become blocked, it results in areas of the Retina being deprived of nourishment and oxygen. A lack of sufficient oxygen supply to the Retina results in a condition called “Retinal Ischemia”. To attempt to compensate for “Retinal Ischemia”, these areas of the Retina then send signals to the body to stimulate the growth of new blood vessels in order to try and reestablish the supply of oxygen.
Proliferative Retinopathy
Proliferative Retinopathy is the most sever stage of Diabetic Retinopathy and carries a significant risk of vision loss. The Retina responds to a lack of oxygen, or “Retinal Ischemia”, by attempting to compensate for the reduced circulation by growing new, but abnormal blood vessels-a process called “neovascularization”. When Retinal Neovascularization is present, you have progressed into the stage of Diabetic Retinopathy called Proliferative Retinopathy. It might seem that new blood vessel growth or neovascularization is a desirable event as it will provide the Retina with greater blood flow and thus more oxygen and nutrients. However this is not the case at all. Retinal Neovascularization is formed from new blood vessels that are extremely fragile and tend to break easily and hemorrhage into the Vitreous. If left untreated, Proliferative Retinopathy may lead to bleeding into the Vitreous and Retinal Detachment with profound vision loss.
Proliferative Retinopathy is treated with either Retinal Laser Photocoagulation Treatment alone or Retinal Laser Photocoagulation Treatment in conjunction with a surgical procedure called a Vitrectomy. During a Vitrectomy, the surgeon will remove the Vitreous that has been filled with blood or scar tissue.
It may be possible for patients to have Proliferative Retinopathy and Retinal Neovascularization and yet still have good vision. Even if Proliferative Retinopathy and Retinal Neovascularization do not appear to be causing any vision loss, it is critical that they be treated as quickly as possible in order to stop the progression and preserve good vision.