Shuangdan Mingmu Capsule for Diabetic Retinopathy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE: To systematically evaluate the efficacy and safety of the Shuangdan Mingmu capsule in the treatment of diabetic retinopathy (DR). METHODS: Common Chinese and English databases, including PubMed, Medline, Embase, VIP, Wanfang, and the Chinese National Knowledge Infrastructure (CNKI), were searched from their inception to May 31, 2022. According to the Cochrane Handbook, two reviewers independently evaluated and collected data on the included studies. Meta-analysis was performed by RevMan software 5.4. RESULTS: Seven trials with a total of 835 patients were included. The clinical effectiveness rate was defined as the primary outcome, and the TCM symptom score, Chinese-Version Low Vision Quality of Life Questionnaire (CLVQOL) scores, macular thickness, hemorrhagic spot area, vascular endothelial growth factor levels, platelet-derived growth factor levels, and the incidence of adverse effects were the secondary outcome. The results of the meta-analysis showed that, compared with conventional medical treatment alone, the Shuangdan Mingmu capsule combined with conventional treatment could significantly improve the clinical effectiveness rate of treating DR (OR = 4.07, 95% CI (2.10, 7.89), p < 0.0001), and reduce the incidence of adverse reactions in DR patients (OR = 0.47, 95% CI (0.26, 0.86), p=0.01). In addition, other results showed that TCM symptom score(OR = −3.47, 95% CI (−3.84, −3.10), p < 0.00001); CLVQOL scores (OR = 23.93, 95% CI (21.37, 26.49), p < 0.00001); macular thickness (OR = −47.34, 95% CI (−50.67, 44.00), p < 0.00001); hemorrhagic spot area (OR = −0.91, 95% CI (−1.01, −0.81), p < 0.00001); vascular endothelial growth factor levels (OR = −45.76, 95% CI (−49.74, 41.79), p < 0.00001); platelet-derived growth factor levels (OR = −1.73, 95% CI (−2.15, −1.31), p < 0.00001). CONCLUSION: Compared with conventional treatment alone, the Shuangdan Mingmu capsule combined with conventional treatment is more effective and safer in the treatment of diabetic retinopathy. However, due to the limitations of the included studies, more high-quality studies are still needed to further assess the efficacy and safety of the Shuangdan Mingmu capsule in the treatment of diabetic retinopathy.