AIM: To explore the clinical effect of micro-pulse laser at 577nm threshold in treatment of diabetic macular edema(DME).

METHODS: The clinical data of 48 patients with DME(64 eyes)were retrospectively analyzed. The patients with micro-pulse laser at 577nm threshold were included in observation group(26 cases, 35 eyes), and the patients who underwent conventional grid-like laser were included in control group(22 cases, 29 eyes). The best corrected visual acuity(BCVA)(LogMAR visual acuity chart), central macular foveal thickness(CFT), mean tetinal sensitive(MS)and mean visual deviation(MD)were compared before surgery and at 1, 3 and 6mo after surgery. And duration of fundus hard exudate and the occurrence of complications after surgery were analyzed in the two groups.

RESULTS: At 1, 3 and 6mo after surgery, the LogMAR visual acuity test results and CFT levels in the two groups were significantly decreased compared with those before surgery, and the indexes in observation group were significantly lower than those in control group at the same time(0.30±0.09 vs 0.35±0.10, 0.19±0.07 vs 0.26±0.09, 0.13±0.04 vs 0.18±0.05; 349.26±21.80 μm vs 364.37±23.91μm, 314.46±20.49μm vs 335.07±22.68μm, 328.35±21.74μm vs 352.43±23.60μm)(all P<0.05). Compared with preoperative, the MS and MD levels in observation group were significantly increased, and significantly higher than that in control group at the same time(5.83±1.16dB vs 4.22±1.04dB, 6.38±1.29dB vs 4.49±1.17dB, 6.75±1.22dB vs 4.68±1.20dB, -5.53±1.41dB vs -7.66±1.52dB, -5.09±1.30dB vs -7.26±1.39dB, -4.68±1.14dB vs -7.05±1.26dB)(all P<0.05). The duration of fundus hard exudate in observation group was significantly lower than that in control group(3.39±0.80mo vs 4.25±1.14mo)(P<0.05). Within 6mo after surgery, the incidence rate of eyeball pain in observation group was significantly lower than that in control group \〖3%(1/35)vs 24%(7/29)\〗(P<0.05), but there were no statistically significant differences in the incidence rates of anterior chamber inflammatory response, visual field defect, intraocular hypertension and corneal edema.

CONCLUSION: Micro-pulse laser at 577nm threshold is safe and effective for DME.