Bariatric Surgery No Guarantee Against Worsening Diabetic Retinopathy

By Reuters Staff

August 07, 2017

NEW YORK (Reuters Health) – Bariatric surgery does not prevent progression of diabetic retinopathy (DR), according to findings from a new observational study.

“All diabetic patients should attend regular DR screening post bariatric surgery to allow early detection of potentially sight-threatening changes, particularly among those with identifiable risk factors,” Dr. Yunzi Chen of Sunderland Eye Infirmary in Sunderland, UK, and colleagues state in their report, published in Eye, online July 21.

Bariatric surgery leads to better glycemic control for patients with type 2 diabetes, with 80% achieving remission within two years, Dr. Chen and colleagues note. But studies of the effect of weight-loss surgery in microvascular complications such as DR have had mixed results.

“As observed during intensification of diabetes management in pregnancy, initiation of insulin pumps, and after pancreatic transplantation, rapid improvement in glycemic control may cause a paradoxical worsening in DR,” they add.

In an observational retrospective study, the researchers analyzed data from 102 patients with type 2 diabetes who had undergone bariatric surgery at one specialist bariatric unit between 2009 and 2015. Before surgery, 68% did not have DR, while 30% had background retinopathy, 1% pre-proliferative retinopathy, and 1% proliferative retinopathy.

At the first visit after surgery, 19% of patients had new-onset DR, 70% were stable, and 11% had improved. Proportions remained similar during each subsequent postoperative visit.

Risk factors for worsening DR included having retinopathy before surgery and a higher preoperative HbA1c level (odds ratio, 1.07, for every 1-mmol/mol increase above 53 mmol/mol). Risk was also higher with younger age (OR, 0.93, for each 1-year age increase) and male sex. A smaller percentage change in HbA1c level after surgery also was associated with an increased risk of DR worsening after the first postoperative visit.

“Bariatric surgery does not guarantee improvement or prevention of DR, despite improved HbA1c in 86% of our patients and 42% achieving normalized HbA1c,” the authors write. They note that awareness of the need to screen patients for DR progression after bariatric surgery is limited; indeed, two patients in their cohort were discharged from the DR screening service after surgery.

“Our results support the current UK NHS diabetic eye screening program recommendations that all patients should be screened annually if there has ever been a definite diagnosis of diabetes,” they conclude, “even if they are in remission due to an intervention such as bariatric surgery.”

Dr. Chen was not available for an interview by press time.


Eye 2017.