Abstract
Purpose: :
To evaluate current standard–of–care modified ETDRS focal/grid photocoagulation (mETDRS) as compared with a novel, potentially milder but potentially more extensive mild macular grid (MMG) laser technique for treatment of diabetic macular edema (DME). The MMG technique places barely visible burns in the entire macula in both thickened and unthickened retina without the direct treatment of microaneurysms.
Methods: :
This initial clinical trial performed by the Diabetic Retinopathy Clinical Research Network (DRCR.net) comprised 79 sites in 30 states. The trial compared the effectiveness of mETDRS and MMG in patients with diabetes who were 18 years or older with vision acuity of 20/400 or better in at least one eye, previously untreated edema within 500 microns of the center of the macula and OCT retinal thickness > 250 microns in the central subfield and/or >300 microns in at least one of the four inner subfields. Visual acuity, fundus photographs and OCT measurements were obtained at baseline and follow–up at 3.5, 8, and 12 months. Treatment was repeated if DME persisted. 162 and 161 eyes were randomized to the mETDRS and MMG techniques, respectively. Twelve–month OCT data are 92% complete and will be finalized by January 2006. Final data will be presented.
Results: :
For the 92 and 96 eyes randomized to mETDRS and MMG respectively, with baseline center point thickness ≥ 225 microns and complete 12 month data, median baseline acuity was 74 letters (approximately 20/32) and median center point thickness was 342 microns. At the 12 month visit, median center point retinal thickness had decreased 55 microns in the mETDRS group versus 38 microns in the MMG group (p=0.09). Visual acuity change was also similar with mETDRS having a median gain of 1 letter versus MMG a median change of zero letters at the 12 month visit (p=0.22). No differences in adverse events were noted between the two treatment approaches.
Conclusions: :
Within the first 12 months of treatment, MMG is no more effective than the more extensively evaluated current standard mETDRS photocoagulation approach. Supported by NEI grants U10 EY14231, 5 U10 EY14269–03, 5 U10 EY14229.
Keywords: diabetic retinopathy • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • macula/fovea