Comparison of the efficacy and safety of anti-VEGF monotherapy versus anti-VEGF therapy combined with subthreshold micropulse laser therapy for diabetic macular edema

The purpose of this study is to compare the efficacy and safety of 577-nm subthreshold micropulse laser (SML) and intravitreal bevacizumab injection (IVB) combined therapy with IVB monotherapy in the treatment of diabetic macular edema (DME). This retrospective study included 80 eyes of 80 patients; 40 eyes were treated with IVB monotherapy, and 40 eyes were treated with SML-IVB combined therapy. The mean number of required IVB injections and changes of best corrected visual acuity (BCVA) and central macular thickness (CMT) values were compared between the groups. The mean age of the patients was 60.19±7.43 years. The baseline characteristics of the patients were similar between the groups. In the SML-IVB combined group, the mean number of required SML sessions was 2.1±0.81. The mean number of required IVB injections was 4.38±0.81 in the SML-IVB combined group and 5.65±1.51 in the IVB monotherapy group (p<0.05). The increase of the BCVA was significant in the SML-IVB combined group at the 3rd, 6th, 9th, and 12th months; however, in the IVB monotherapy group, it was only significant at the 3rd month (p<0.05). The mean CMT values of the 3rd, 9th, and 12th months were similar between the groups (p>0.05); only at the 6th month was it significantly lower in the SML-IVB combined group (p<0.05). When compared with baseline, the decrease of the CMT was statistically significant in both groups at the 3rd, 6th, 9th, and 12th months (p<0.05). In this study, a significant benefit of adding SML to IVB therapy was found with less IVB need, although a very significant increase in BCVA could not be achieved. The use of SML-IVB combined treatment may be an effective and safe alternative for DME.