Original Article
The Impact of Bariatric Surgery on Diabetic Retinopathy: A Systematic Review and Meta-Analysis

https://doi.org/10.1016/j.ajo.2020.12.033Get rights and content

Highlights

  • •

    Bariatric surgery results in fewer cases of diabetic retinopathy compared with medical management.

  • •

    Early worsening can occur, especially in patients with existing proliferative diabetic retinopathy.

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    Vigilant screening for sight-threatening diabetic retinopathy is needed before bariatric surgery.

Objective

While bariatric surgery induces remission of type 2 diabetes mellitus and reduces other microvascular complications, its impact on diabetic retinopathy (DR) is unclear. Some trials suggest early worsening of DR postsurgery because of rapid improvements in hyperglycemia. This meta-analysis sought to estimate the impact of bariatric surgery on DR for obese patients compared with medical treatment.

Design

Systematic review and meta-analysis.

Methods

The Medline, Embase, and PubMed Central databases were searched to March 2020. Primary studies comparing DR in patients undergoing bariatric surgery with those undergoing medical management were included. Results were meta-analyzed using a random-effects model. Primary outcomes included prevalence of all DR and sight-threatening DR after surgery. Secondary outcomes included worsening of DR within and beyond 12 months.

Results

Overall, 14 studies comprised of 110,300 surgical patients and 252,289 control subjects were included. Surgical patients had a statistically significantly lower postoperative prevalence of all DR (relative risk [RR] 0.17 [95% confidence interval {CI} 0.13-0.22]) and sight-threatening DR (RR 0.47 [95% CI 0.27-0.82]). Early worsening of DR and progression to sight-threatening DR had occurred more often in those with more severe DR initially. However, beyond 12 months, bariatric surgery resulted in significantly fewer patients with worsened DR (RR 0.29 [95% CI 0.16-0.54]). The overall risk of bias was low; estimates of relative effects had low to moderate certainty of evidence.

Conclusion

While bariatric surgery was associated with fewer cases of all and sight-threatening DR, early worsening was more severe in patients with existing sight-threatening DR. These findings argue for frequent monitoring during the first postoperative year.

Section snippets

Methods

We performed this study in accordance with The Cochrane Handbook for Systematic Reviews of Interventions32 and reported findings following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.33 The protocol was registered on PROSPERO under CRD42020201298.

Results

The initial search returned 3368 unique citations, and 117 full texts were reviewed. Of these, 15 records met our inclusion criteria. Supplemental Figure 1 shows a detailed Preferred Reporting Items for Systematic Reviews and Meta-analyses flow diagram.

Discussion

The present analysis is the most comprehensive systematic review conducted to date to investigate the effects of bariatric surgery on DR. Our findings suggest that the risk of having any DR for patients who underwent bariatric surgery was 83% lower than that of nonsurgical patients during follow-up. Bariatric surgery also significantly reduced the prevalence of STDR by 53% during follow-up when compared with nonsurgical patients. In addition, 71% fewer patients who had undergone surgery had

Conclusions

The risks of DR and STDR development were significantly lower in patients who were obese with T2DM who underwent bariatric surgery compared with those did not undergo surgery. In addition, severity of DR at baseline was an important sign of early worsening of DR postoperatively, suggesting the need for early vigilant DR screening for patients with existing STDR who undergo bariatric surgery. Ultimately, bariatric surgery resulted in a reduced rate of progression of DR compared with nonsurgical

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