CCL2 and diabetic macular edema: Yoshimura et al collected vitreous specimens from 345 eyes with several retinal diseases such as diabetic retinopathy (DR), central retinal vein occlusion (CRVO), rhegmatogenous retinal detachment, and diabetic macular edema; they did not observe an elevated concentration of TNF-α in any of these disorders as compared to the control group (patients with idiopathic macular hole or macular pucker)20, but they did detect elevated concentrations of IL-6, IL-8 and monocyte chemoattractant protein-1 (MCP-1).