Diabetic retinopathy is a complication of both type 1 and type 2 diabetes, and it can lead to blindness. Now the results of a three-year study show that people with diabetic retinopathy may get some help from a drug used to treat macular degeneration.
What is diabetic retinopathy?
Diabetic retinopathy involves damage to the blood vessels in the retina, which is the part of the eye responsible for healthy vision. According to the National Eye Institute, 40 to 45 percent of people with diabetes have some level of diabetic retinopathy, which is the most common eye disease that affects diabetics.
To help prevent diabetic retinopathy, individuals need to control their blood sugar, blood pressure, and cholesterol. However, if vision deteriorates, laser surgery may become necessary to save eyesight. Frequently, more than one laser session is necessary to complete treatment.
Potential new treatment for diabetic retinopathy
In a study conducted by Michael Ip, MD, of the University of Wisconsin and his colleagues, the macular degeneration drug called ranibizumab (Lucentis) was shown to slow the progression of diabetic retinopathy and improve visual acuity when compared with sham injections. The study was presented at the recent American Academy of Ophthalmology meeting in Chicago.
More than 700 patients participated in the study, which involved receiving an injection once a month: 257 received a sham injection, 250 were given 0.3 mg ranibizumab, and 252 were given 0.5 mg ranibizumab. After two years, patients in the sham group were switched to 0.5 mg ranibizumab for the third year of the study.
Here's what the researchers found:
- At the end of two years, ranibizumab not only helped prevent progression of diabetic retinopathy but even caused most patients to improve.
- Visual acuity improved among patients who were originally in the sham treatment group at the end of the third year
- Significantly more patients who switched from the sham to active treatment experienced progression to diabetic retinopathy than did patients in either of the original active treatment groups
Overall, the results of the study suggested the following, according to Ip:
- There is "strong evidence that ranibizumab is effective in reducing the severity of diabetic retinopathy"
- Delaying treatment with ranibizumab reduces the ability of the drug to improve the severity of diabetic retinopathy
In July 2012, a Food and Drug Administration (FDA) advisory panel recommended the agency approve Lucentis for another diabetic eye disease called diabetic macular edema. In fact, diabetic macular edema develops from diabetic retinopathy when the damaged blood vessels leak into the macula (central part of the eye containing nerve cells responsible for sensing light). The FDA approved Lucentis for diabetic macular edema in August 2012.
The bottom line
Although the results of this study strongly suggest ranibizumab can reduce the severity of diabetic retinopathy, more research is needed. In addition, researchers would like to find a way to reduce the need for monthly injections while still maintaining the same level of efficacy.
Dr. Ip has suggested clinicians think about using ranibizumab alone or along with laser treatment to help patients who have diabetic retinopathy. If future studies go well, this macular degeneration drug could be approved for patients with diabetic retinopathy.
Ip MS et al. Effects of intravitreal ranibizumab on diabetic retinopathy severity: 36-month data from RISE and RIDE trials. AAO 2012; abstract PA054
National Eye Institute