Efficacy and safety of triamcinolone acetonide injection combined with laser photocoagulation in the treatment of diabetic macular edema: a systematic review and meta-analysis

Background: Diabetic macular edema (DME) is a type of retinopathy caused by diabetes, and the 2 main clinical treatment modalities are drug therapy intravitreal triamcinolone acetonide injection (IVTA) and laser photocoagulation. This meta-analysis investigated the efficacy of combining both the 2 treatment modalities. Methods: The Embase, Cochrane library, PubMed, and Ovid databases were searched for English literatures. The literatures were screened and assessed for the risk of bias, after that the Revman 5.4 software was used to conduct the meta-analysis. Results: A total of 8 articles, including 549 patients, were included in this study. Meta-analysis showed that the effect of (IVTA + laser) on early central macular thickness (CMT) was not significantly different with IVTA alone [mean difference (MD) =-5.13, 95% confidence interval (CI): -17.06 to 6.80, P=0.40], however, significantly different with laser alone (MD =-94.31, 95% CI: - 135.04 to - 53.58, P<0.00001). Similarly, the effect of (IVTA + laser) on early best corrected visual acuity (BCVA) was not significantly different with IVTA alone (MD =0.02, 95% CI: -0.03 to 0.07, Z=0.79, P=0.43). but different with laser alone [MD =-0.20, 95% CI: -0.24 to -0.16, Z=10.16, P<0.00001). The effect of (IVTA + laser) on long-term CMT was not significantly different with IVTA alone (MD =-66.90, 95% CI: -132.66 to -1.15, Z=1.99, P=0.05) nor with laser alone (MD =-15.86, 95% CI: -31.37 to -0.35, Z=2.00, P=0.05). Similarly, the effect of combined intervention (IVTA + laser) on long-term BCVA was not significantly different with IVTA alone ( MD =-0.18, 95% CI: -0.39 to 0.03, Z=1.71, P=0.09) nor with laser alone (MD =-0.11, 95% CI: -0.23 to 0.01, Z=1.74, P=0.08). Administration of IVTA before laser was superior to laser alone (MD =-0.19, 95% CI: -0.31 to -0.07, Z=3.09, P=0.002). Discussion: The effect of IVTA + laser therapy is similar to IVTA alone, but superior to laser alone for the early treatment of DME. However, the long-term effect is similar to IVTA alone or laser alone, a better therapeutic effect can be achieved if IVTA is administered before laser treatment.