Rebecca Thomas, BSc and colleagues of Swansea University in Wales reported at the American Diabetes Association meeting that seven of the 40 diabetes patients screened a year before and again after bariatric surgery progressed in the development of retinopathy, for a rate of 17.5%, compared with the 2% to 4% of diabetes patients who develop retinopathy each year.

The reduction in fasting glucose after bariatric surgery was 151 mg/dL among those whose retinopathy progressed compared with 49 mg/dL in those who had regression and 29 mg/dL in those with no change in retinopathy.

"A rapid improvement, termed the normoglycemic re-entry phenomenon, may result in the progression of preexisting diabetic retinopathy," Thomas noted at the session, although Wolfe cautioned that any mechanism is speculative at this point.