This systemic review and meta-analysis assessed prevalence of diabetic retinopathy including sight-threatening diabetic retinopathy after surgery. They included 14 studies with 110,300 surgical patients and 252,289 control subjects. They proposed that the risk of having any form of diabetic retinopathy was reduced by 83% by undergoing bariatric surgery compared to non-surgical patients. In addition, they found a 53% reduction in the prevalence of sight-threatening diabetic retinopathy when compared to non-surgical patients and, 71% less patients that had undergone surgery experienced diabetic retinopathy progression after a year. It is already known that rapid improvements of glycaemic control can worsen diabetic retinopathy. They found during this analysis that early progression of all diabetic retinopathy was not significantly different between the surgical and non-surgical group who had non-proliferative diabetic retinopathy at baseline. However, in those surgical patients with proliferative diabetic retinopathy, progression was significantly higher in the first 12 months than non-surgical patients. They therefore concluded that after 12 months, bariatric surgery was associated with significant long-term reduction in diabetic retinopathy progression. However, it was important to ensure screening preoperatively and during the first postoperative year, especially for those patients with proliferative diabetic retinopathy.