AIM: To analyze the clinical effect of 577nm subthreshold micropulse laser(SML)photocoagulation combined with intravitreal injection of Conbercept in the treatment of diabetic macular edema(DME)after vitrectomy in patients with proliferative diabetic retinopathy(PDR).

METHODS:A retrospective analysis was performed on 29 cases(30 eyes)of PDR patients who had DME after vitrectomy in our hospital from January 2019 to June 2021. They were divided into two groups according to different treatment methods: 14 cases(14 eyes)in the single injection group received intravitreal injection of Conbercept, and 15 cases(16 eyes)in the combined treatment group received 577nm SML photocoagulation in the macular area combined with intravitreal injection of Conbercept. The changes in best corrected visual acuity(BCVA)and central macular thickness(CMT)before and at 6 and 12mo after treatment, as well as the changes of multifocal electroretinogram(mfERG)before and at 12mo after treatment were compared between the two groups.

RESULTS: The BCVA(LogMAR)of patients in both groups improved and CMT decreased after treatment for 6 and 12mo(all P<0.001). There were no significant differences in BCVA(LogMAR)and CMT before treatment and 6mo, 12mo after treatment between single injection group and combined treatment group(all P>0.05). Compared with the combined treatment group, the amplitude was slightly lower(23.02±3.13 vs. 26.50±3.33 μV/deg²)and the latency time was prolonged(38.75±1.62 vs. 34.21±3.06ms)in single injection group at 12mo(all P≤0.001). The average injection times in single injection group was 8.14±1.46, and 5.05±1.51 in combined treatment group at 12mo after treatment(P<0.05).

CONCLUSION: 577nm SML photocoagulation combined with intravitreal injection of conbercept can effectively relieve macular edema, improve BCVA and visual function of macular area and reduce the injection times of conbercept for DME patients.