Diffuse Diabetic Macular Edema – 18 Months Observation of the 577 nm Subthreshold Micropulse Laser Treatment Results

Purpose
To evaluate the efficacy of subthreshold micropulse laser treatment in diabetic macular edema at 18 months of follow-up.

Material and methods
112 eyes of 112 patients with diabetic macular edema were treated with subthreshold micropulse yellow laser and followed up every 3 months. If the edema was present, the treatment was repeated. The mean age of patients was 65.64±8.75 years. The mean duration of diabetes was 14.4±8.75 years. The glycated hemoglobin level was ≤ 7mg% only in 18 patients. The primary outcomes were the mean change in best-corrected distance and near visual acuity and central macular thickness. Secondary outcomes included variables correlation with glycated hemoglobin level.

Results
The mean baseline best-corrected distance visual acuity was 0.31±0.2 and improved finally to 0.47±0.2 (p=0.00). The mean baseline best-corrected near visual acuity was 1.08±0.8 and improved finally to 0.56±0.2 (p=0.00). The mean baseline central macular thickness was 449.16±162.5 µm and improved finally to 256.6±118.2 µm (p=0.01). The laser treatment was performed in 7 patients one time, in 16 - two times, in 73 - three times, and in 16 - four times. There was no significant correlation between glycated hemoglobin level and disease duration, baseline and final best-corrected distance and near visual acuity and central macular thickness. There was significant negative correlation between glycated hemoglobin level and patients’ age.

Conclusions
Subthreshold micropulse yellow laser showed long-term efficacy in diabetic macular edema treatment. The level of glycated hemoglobin was not important for initial distance and near best-corrected visual acuity and central macular thickness.