Retinal sensitivity following subthreshold diode laser micropulse photocoagulation for diabetic macular edema

Abstract To report the retinal sensitivity after subthreshold diode laser micropulse photocoagulation(SDM) to evaluate its safety. Eight eyes of 8 diabetic patients with clinically significant macular edema were treated with SDM. SDM was applied with a 15% duty cycle, 0.2 to 0.3 sec, 200 microm, at 700 to 800 mW. Postoperative retinal sensitivity (1-2 weeks) was compared to preoperative retinal sensitivity measured by microperimeter-1 (MP-1, Nidek technologies, Padova, Italy) using a 1 x 1 mm square test grid with 49 stimulus locations. The retinal sensitivity improved (more than 2 dB) in 3 eyes and remained stable (within 2 dB) in 5 eyes. The median retinal sensitivity increased significantly in 5 eyes and decreased significantly in 3 eyes. The average retinal sensitivity of 8 eyes was 12.04 +/- 3.69 dB before laser treatment, and 13.20 3.47 dB after laser treatment and there was no statistically significant change in retinal sensitivity at 2 weeks (p = 0.09). Short duration SDM for diabetic macular edema has no significant effect on retinal sensitivity.