CCL2 and non-proliferative diabetic retinopathy: To explore the effect of calcium dobesilate combined with hypoglycemic drugs in the treatment of cataract complicated with non-proliferative diabetic retinopathy (NPDR) and its effects on fundus microcirculation, intercellular adhesion molecule 1 (ICAM-1), mono - cyte chemoattractant protein 1 (MCP-1), and macrophage migration inhibitory factor (MIF).