Effect of Focal/Grid Photocoagulation on Visual Acuity and Retinal Thickening in Eyes With Non–center-Involved Diabetic Macular Edema

In Brief Purpose: To report visual acuity and anatomic changes from baseline to 12 months after modified Early Treatment Diabetic Retinopathy Study (ETDRS)-style (focal/grid) photocoagulation in eyes with non–center-involved (non-CI) clinically significant macular edema. Methods: Visual acuity, optical coherence tomography, fluorescein angiography, and fundus photography data were analyzed from eyes with non-CI clinically significant macular edema treated with modified ETDRS-style (focal/grid) photocoagulation in a Diabetic Retinopathy Clinical Research Network trial. Results: Among the 22 eyes (of 22 patients) with 12-month follow-up, median visual acuity letter score remained within 1 letter of baseline over 12 months. The median central subfield retinal thickness decreased by 10 μm, median total macular volume decreased by 0.2 mm3, and median fluorescein leakage area within the grid decreased by 0.7 disk areas. Conclusion: We are unaware of any other systematic evaluation of eyes with non-CI clinically significant macular edema since the ETDRS. Focal/grid laser in these non-CI eyes was associated with relatively stable visual acuity and retinal thickness measurements, and decreased fluorescein leakage area at 1 year. One-year visual acuity results are consistent with those published by the ETDRS, despite the intervening significant differences in the management of diabetes. Although this was a small study without a concurrent control group, the ETDRS recommendation to consider focal/grid laser in eyes with non-CI clinically significant macular edema still seems appropriate. To the authors’ knowledge, this is the first report since the ETDRS to evaluate focal/grid laser for non-center involved clinically significant macular edema. Laser was associated with stable acuity and retinal thickness, and decreased fluorescein leakage area at 1 year. Acuity results are consistent with those of the ETDRS, despite intervening differences in diabetes management.