Efficacy of traditional Chinese medicine combined with Western drugs for the treatment of non-proliferative diabetic retinopathy: a meta-analysis

Objective This study aimed to evaluate the efficacy of combination therapy with Chinese and Western medicine for non-proliferative diabetic retinopathy (NPDR). Methods This systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) under registration number CRD420261357240. PubMed, China Knowledge Network, China Wanfang, and Embase databases were searched for literature on the combination of Chinese and Western medicines in the treatment of NPDR from the inception of each database. Two evaluators independently screened the literature, extracted data, and evaluated the risk of bias of the included studies, and the data were analyzed using the RevMan 5.3 software for statistical analysis. Results Six relevant studies (total n = 1,127) were included after rigorous screening. Risk of bias assessment revealed that all included studies had high or unclear risk in at least two domains. GRADE assessment indicated low to moderate quality of evidence across outcomes. Compared with Western medicine monotherapy, combination therapy showed superior effects on visual acuity (mean difference (MD) = 0.09, 95% confidence interval (CI): 0.07–0.11, I 2 = 0%, five studies), whole blood high-cut viscosity (MD = −0.55, 95% CI: −0.83 to −0.27, I 2 = 88%, four studies), whole blood low-cut viscosity (MD = −0.61, 95% CI: −1.12 to −0.11, I 2 = 89%, four studies), Traditional Chinese Medicine (TCM) symptom score (MD = −2.29, 95% CI: −4.26 to −0.32, I 2 = 85%, three studies), and TCM symptom efficacy (odds ratio (OR) = 4.07, 95% CI: 1.37–12.10, I 2 = 71%, three studies). Publication bias was not detected (Egger’s test p = 0.18). Clinical efficacy (OR = 2.96, 95% CI: 2.08–4.21, I 2 = 39%, six studies) was consistently favorable across studies. Conclusion The combination of Chinese and Western medicines in the treatment of NPDR can improve visual acuity, improve blood rheology, reduce the clinical symptoms of Traditional Chinese Medicine syndromes, increase the efficacy of TCM treatments, delay disease progression, alleviate the symptoms, and optimize patients’ quality of life, demonstrating remarkable effects and promising clinical application.