Abstract:AIM: To systematically evaluate the association between nailfold capillaroscopic findings and diabetic retinopathy (DR) and compare findings in diabetic patients with and without DR. METHODS: PubMed, Web of Science, and Embase databases were searched from inception to February 2024. The quality of the included studies was evaluated using a National Institutes of Health (NIH) Quality Assessment tool for Observational Cohort and Cross Sectional Studies. Meta-analysis was conducted to compare the findings of nailfold capillaroscopy between diabetic patients with or without DR. Subgroup analysis was employed to investigate the source of heterogeneity. RESULTS: Totally 12 studies with 1349 diabetic patients were included, of which 628 had DR. The overall quality of included studies was acceptable. Patients with DR had increased arteriolar diameters [mean difference (MD): 2.68, 95% confidence interval (CI): 0.64-4.72] and a higher risk of developing nailfold capillaroscopic abnormalities, including bushy capillaries [odds ratio (OR): 2.82, 95%CI: 1.65-4.80], neoformation (OR: 4.61, 95%CI: 3.15-6.76), megacapillaries (OR: 8.37, 95%CI: 5.07-13.80), tortuosity (OR: 7.29, 95%CI: 2.76-19.22), microhemorrhages (OR: 6.16, 95%CI: 2.48-15.26), meandering capillaries (OR: 4.68, 95%CI: 1.05-20.80) and avascular areas (OR: 7.92, 95%CI: 2.68-23.38). The presence of tortuous capillary was more common in DR in India than in Turkey, while avascular area in the nailfolds was linked to DR only in India (OR: 11.28, 95%CI: 3.91-32.60). Among the nailfold capillaroscopic abnormalities, tortuosity, microhemorrhage, and meandering capillary showed no significant correlation with the severity of DR, except for avascular area (P=0.04). CONCLUSION: There are significant associations between nailfold capillaroscopic findings and the presence of DR, supporting its potential as a non-invasive technique for monitoring microvascular changes in diabetic patients. However, further research is needed to validate its utility as an early screening tool for microvascular complications in diabetes.