Diabetic Retinopathy

What is Diabetic Retinopathy?
Doctors usually separate diabetic retinopathy into two categories, background and proliferative.  Background diabetic retinopathy includes bleeding and leakage from abnormal blood vessels and ischemia (lack of oxygen) due to blood vessel shut-down.  In response to ischemia, abnormal blood vessels can develop and the retinopathy is then called proliferative diabetic retinopathy.


Who is affected by Diabetic Retinopathy?
Diabetic retinopathy is a major cause of blindness throughout the world, and the leading cause of blindness in the United States in people between the ages of 20 and 60.  In juvenile, or Type I, diabetes, retinopathy usually does not present until 10 years following the initial diabetes diagnosis.  However, by 25 years duration of diabetes, approximately 95% of all people with diabetes will have some type of retinopathy.  In Type II, or adult-onset diabetes, retinopathy can be present at the time of the initial diagnosis.  Those with Type II diabetes should have a dilated, thorough exam after the diagnosis is established.


How does Diabetic Retinopathy affect the eye?
Background diabetic retinopathy affects the vision by either allowing leakage of fluid into, or by closing the blood supply of the center of vision. The former is called macular edema and the latter is called macular ischemia. When proliferative disease is present, the abnormal vessels can break and bleed into the center of the eye causing a vitreous hemorrhage. If left untreated, proliferative disease can also lead to retinal detachments and blindness.


How is Diabetic Retinopathy treated?
Evaluation of diabetic retinopathy involves careful retinal examination and a fluorescein angiogram.  Based on the findings, if there is evidence of diabetic macular edema (DME), the doctor may advise laser treatment.  The laser is used to seal the abnormal, leaking blood vessels, which helps the retina absorb the fluid and reduce the swelling.

If the swelling persists despite laser treatment, there are several treatment options. Some patients receive a steroid or Avastin injections either next to or into the eye. Though such injections may sound painful, there are ways to make both procedures almost painless. Some patients benefit from removal of the gel-like fluid in the eye, known as the vitreous, by a surgical procedure called a vitrectomy.

When proliferative diabetic retinopathy is present, a laser treatment call pan-retinal photocoagulation can stabilize more than half of all cases of proliferative diabetic retinopathy. In cases of proliferative diabetic retinopathy in which there is persistent diabetic vitreous hemorrhage and/or retinal detachment, surgery may be required.

If surgery is indicated, the retinal specialist performs a pars plana vitrectomy to remove the hemorrhage and/or fibrous scar tissue.  The surgery is done under local anesthesia in a hospital or ambulatory surgery center.  Tiny instruments, smaller than the tip of a pencil, remove the vitreous fluid, hemorrhage, and any fibrous tissue around the retina.  Surgery may also involve laser to treat the retina and, occasionally, a gas bubble to help hold the retina in place during the healing phase.  Eventually, the gas bubble dissolves and clear fluid replaces it naturally.


For more information about Diabetic Retinopathy, you may wish to visit/contact:

National Eye Institute (NEI)
Diabetic Retinopathy: What you should know