VEGFA and diabetic retinopathy: A previous study measured the concentrations of VEGF and IL-6 in aqueous humor in patients with nonproliferative diabetic retinopathy by enzyme linked immunosorbent assay (ELISA) during cataract surgery [13] and demonstrated that high VEGF levels in the aqueous humor predict a significant risk of postoperative exacerbation of macular edema [13].