title: Bariatric surgery is associated with less progression of diabetic retinopathy: A systematic review and meta-analysis.
abstract: 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.
  
  
  METHODS
  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.
authors.affiliation: Department of Ophthalmology, Soonchunhyang University College of Medicine, Soonchunhyang University Seoul Hospital, Seoul, South Korea; Graduate School of Medical Science and Engineering, KAIST, Daejeon, South Korea.
authors.forename: Yong Joon
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Division of Biological Warfare Preparedness and Response, Armed Forces Medical Research Institute, Daejeon, South Korea.
authors.forename: Byoung Hyuck
authors.initials: BH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, South Korea.
authors.forename: Bo Mi
authors.initials: BM
authors.lastname: Choi
authors.affiliation: Department of Ophthalmology, Soonchunhyang University College of Medicine, Soonchunhyang University Seoul Hospital, Seoul, South Korea.
authors.forename: Hae Jung
authors.initials: HJ
authors.lastname: Sun
authors.affiliation: Department of Ophthalmology, Soonchunhyang University College of Medicine, Soonchunhyang University Seoul Hospital, Seoul, South Korea.
authors.forename: Sung Jin
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Soonchunhyang University College of Medicine, Soonchunhyang University Seoul Hospital, Seoul, South Korea. Electronic address: ckseek@naver.com.
authors.forename: Kyung Seek
authors.initials: KS
authors.lastname: Choi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D050110:Bariatric Surgery; D003924:Diabetes Mellitus, Type 2 / Q000517:prevention & control* / Q000601:surgery; D003930:Diabetic Retinopathy / Q000517:prevention & control* / Q000601:surgery; D018450:Disease Progression; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult
keywords: Bariatric surgery; Diabetic retinopathy; Meta-analysis