Effects of intensive glycemic control in ocular complications in patients with type 2 diabetes: a meta-analysis of randomized clinical trials

Whether intensive glycemic control can reduce incidence of diabetic retinopathy or other diabetes-associated ocular complications remains undefined. In this meta-analysis, we assessed the effects of intensive versus conventional glycemic control in ocular complications in patients with type 2 diabetes. A systematic literature search of PubMed, Web of Knowledge, and Scopus (until December 12, 2013) was conducted. Randomized controlled trials which compared intensive glycemic control with conventional glycemic control in ocular events in patients with type 2 diabetes were included. Random-effects models were used to measure the pooled odds ratio (OR) with 95 % confidence interval (CI). Seven trials involving 32,523 patients were included. Intensive glycemic control reduced the risks of retinal photocoagulation or vitrectomy (OR 0.86; 95 % CI 0.75-0.98), macular edema (OR 0.65; 95 % CI 0.43-0.99), and progression of retinopathy (OR 0.69; 95 % CI 0.55-0.87). No significant risk reduction was shown in incidence of retinopathy (OR 0.67; 95 % CI 0.26-1.73), cataract surgery (OR 0.88; 95 % CI 0.76-1.03), or severe loss of vision or blindness (OR 0.99; 95 % CI 0.86-1.13). Intensive glycemic control reduces the risk of most retinopathy-related events. But no beneficial effect was shown in ocular endpoint as severe loss of vision or blindness.