Localized changes in retinal vessel caliber after focal/grid laser treatment in patients with diabetic macular edema: a measure of treatment response?

PURPOSE

To compare retinal vessel caliber changes at the macula region and surrounding the optic disk after focal/grid laser treatment for diabetic macular edema.

METHODS

The study included 69 eyes from 46 patients treated with focal/grid laser for diabetic macular edema. Retinal photographs were taken <6 months before and 2 months and 12 months after focal/grid photocoagulation treatment. The diameters of retinal vessels around macula and the optic disk were measured separately before and after treatment. Optic disk and macular diameters were summarized into central retinal arteriolar and venular equivalent and macular retinal arteriolar and venular equivalent.

RESULTS

Median age and duration of diabetes was 60 years and 13 years. There was a statistically significant decrease in diameter of the macular arterioles (macular retinal arteriolar equivalent 73.5 vs. 72.0 μm, P = 0.04) and venules (macular retinal venular equivalent 63.5 vs. 62.4 μm, P = 0.02) after treatment but no difference in central retinal arteriolar equivalent or central retinal venular equivalent before and after treatment. Retinal vascular calibers in control eyes did not change throughout the study.

CONCLUSION

The diameters of macular vessels decreased after focal/grid laser treatment in most eyes. In contrast, vessel calibers at the optic disk did not change. Quantitative measurement of macular vessels may allow physicians to monitor the progress and success of diabetic macular edema treatment.