JAN 05, 2011
Although modified grid laser photocoagulation (MGP) has become the primary U.S. Food and Drug Administration-approved treatment for diffuse diabetic macular edema (DDME), studies have shown a high rate of recurrence or persistence in treated eyes. Intravitreal bevacizumab (IVB) has been reported to be effective in reducing DDME and improving BCVA. Because IVB and MGP work via different pathways, a combination therapy may yield more favorable results than either therapy alone. In this study, researchers evaluated the efficacy of using IVB followed by MGP as a primary treatment of DDME in comparison to MGP or IVB alone. To the authors' knowledge this is the first peer review study evaluating the efficacy of combined IVB and MGP for treatment of DDME.
They randomized 48 patients (62 eyes) to IVB followed by MGP three weeks later, IVB alone, or MGP alone. The combined group showed significant improvement in central macular thickness through all six months of follow up and significant improvement in BCVA through three months. However, no significant improvement in BCVA occurred six months after treatment. The IVB group showed significant improvement only through the first month, and the MGP group showed no significant improvement at any point.
Although the authors conclude that combination IVB and sequential MGP could be used as an initial treatment of DDME, they note that a larger number of patients and a longer follow-up period are needed to verify and confirm the results of the present study. More study is also necessary to select the correct timing for MGP after IVB, and to establish patient selection parameters. The authors plan to compare in a future study the long-term safety and efficacy of this combined therapy versus the use of repeated IVB injections in eyes with DDME.