Calcium dobesilate for diabetic retinopathy: a systematic review and meta-analysis

Many randomized clinical controlled trials have confirmed the efficacy and safety of calcium dobesilate in treating diabetic retinopathy (DR). This systematic review critically evaluated the evidence that links calcium dobesilate to DR. In this fixed-effects meta-analysis, a total of 221 pertinent English-language articles published between January 1975 and October 2013 were identified. Systematic searches of PUBMED, Springer Link and the Cochrane Clinical Trials Database were conducted using the keywords "diabetic retinopathy" and "calcium dobesilate". The extracted information included the study design, inclusion and exclusion criteria, setting, sample size, participant mean age, treatment regime, mean change in best corrected visual acuity, laboratory parameters, capillary fragility, intraocular pressure and fundus manifestations based on the findings of fluorescent angiography. The summary statistics indicated that calcium dobesilate was significantly associated with improving retinal microaneurysms (RR: 0.62, 95%CI: 0.42-0.90, P=0.01), retinal hemorrhages (RR: 0.39, 95% CI: 0.17-0.88, P=0.02); exudates (RR: 0.31, 95% CI: 0.12-0.81, P=0.02), reduction of whole blood viscosity (MD: -0.57 CP, 95% CI: -0.75 to -0.38, P<0.001), plasma viscosity (MD: -0.36 CP, 95% CI: -0.63 to -0.09, P=0.01) and blood cholesterol (MD: -0.48 mg mL(-1), 95% CI: -0.64-0.33, P<0.00001). Intraocular pressure was also significantly reduced (MD: -5.59 mmHg, 95% CI: -6.69 to -4.50, P<0.00001). The results indicate that calcium dobesilate effectively treats DR at the systematic and local ocular levels.