Bariatric surgery is associated with less progression of diabetic retinopathy: A systematic review and meta-analysis.

BACKGROUND: The impact of bariatric surgery on diabetic retinopathy (DR) remains underexplored, and conflicting results have been reported.

OBJECTIVE: To clarify the impact of bariatric surgery on DR.

SETTING: A systematic review and meta-analysis. University Hospital, Korea.

METHODS: A comprehensive database search was performed across PubMed, Embase, Web of Science, and the Cochrane Library from inception to August 2016. Eligible studies included retrospective or prospective studies reporting changes in DR severity as primary or secondary outcomes after bariatric surgery. A random-effects model was used to calculate pooled odds ratios (ORs) and 95% confidence intervals (CIs) for progression of DR.

RESULTS: Twelve studies composed of 876 patients who underwent bariatric surgery were selected for this systematic review. The pooled ORs showed less DR progression in patients with bariatric surgery than in those with medical treatment alone (OR, .47; 95% CI, .22-.99). The postoperative progression odds were not significantly different between patients with and without DR at baseline (OR, 1.04; 95% CI, .35-3.11). Another meta-analysis investigating the effects of surgery depending on pre-existing sight-threatening DR showed no significant difference (OR, 1.88; 95% CI, .29-12.25) with borderline heterogeneity (I2 = 48%). Remission of diabetes could not prevent the development or progression of DR after surgery.

CONCLUSIONS: Bariatric surgery has beneficial effects on DR progression compared with medical treatment alone, but there is currently insufficient evidence to assess the effects on DR regression. The progression odds were not significantly different between patients with and without DR preoperatively.