Efficiency and safety of laser photocoagulation with or without intravitreal ranibizumab for treatment of diabetic macular edema: a systematic review and Meta-analysis

AIM: To compare the therapeutic effect and safety of laser photocoagulation along with intravitreal ranibizumab(IVR) versus laser therapy in treatment of diabetic macular edema(DME).METHODS: Pertinent publications were identified through comprehensive searches of Pub Med, EMBASE, Web of Science, Cochrane Library, and Clinical Trials.gov to identify randomized clinical trials(RCTs) comparing IVR+laser to laser monotherapy in patients with DME. Therapeutic effect estimates were determined by weighted mean differences(WMD) of change from baseline in best corrected visual acuity(BCVA) and central retinal thickness(CRT) at 6, 12, or 24 mo after initial treatment, and the risk ratios(RR) for the proportions of patients with at least 10 letters of improvement or reduction at 12 mo. Data regarding major ocular and nonocular adverse events(AEs) were collected and analyzed. The Review Manager 5.3.5 was used.RESULTS: Six RCTs involving 2069 patients with DME were selected for this Meta-analysis. The results showed that IVR+laser significantly improved BCVA compared with laser at 6mo(WMD: 6.57; 95% CI: 4.37-8.77; P<0.00001), 12mo(WMD: 5.46; 95% CI: 4.35-6.58; P<0.00001), and 24mo(WMD: 3.42; 95% CI: 0.84-5.99; P=0.009) in patients with DME. IVR+laser was superior to laser in reducing CRT at 12 mo from baseline with statistical significance(WMD:-63.46; 95% CI:-101.19 to-25.73; P=0.001). The pooled RR results showed that the proportions of patients with at least 10 letters of improvement or reduction were in favor of IVR+laser arms compared with laser(RR: 2.13; 95% CI: 1.77-2.57; P<0.00001 and RR: 0.37; 95% CI: 0.22-0.62; P=0.0002, respectively). As for AEs, the pooled results showed that a significantly higher proportion ofpatients suffering from conjunctival hemorrhage(study eye) and diabetic retinal edema(fellow eye) in IVR+laser group compared to laser group(RR: 3.29; 95% CI: 1.53-7.09; P=0.002 and RR: 3.02; 95% CI: 1.24-7.32; P=0.01, respectively). The incidence of other ocular and nonocular AEs considered in this Meta-analysis had no statistical difference between IVR+laser and laser alone.CONCLUSION: The results of our analysis show that IVR+laser has better availability in functional(improving BCVA) and anatomic(reducing CRT) outcomes than laser monotherapy for the treatment of DME. However, the patients who received the treatment of IVR+laser may get a higher risk of suffering from conjunctival hemorrhage(study eye) and diabetic retinal edema(fellow eye).