Bariatric surgery may curb diabetic eye disease incidence but worsen existing retinopathy

Reuters Health - 23/01/2021 - Bariatric surgery was associated with fewer cases of diabetic retinopathy (DR), but early worsening was more severe in patients who already had the condition, a systematic review and meta-analysis reveals.

"There are heavy debates in literature regarding whether bariatric surgery would be helpful for DR," Dr. Yung Lee of McMaster University in Hamilton, Ontario, told Reuters Health by email. "(We found) that bariatric surgery lowered the risk of all DR by 83% and sight-threatening DR by 53% compared to medical management."

That said, he noted, "We were surprised to find that early worsening of diabetic retinopathy occurs, in particular for patients with existing proliferative disease. These findings suggest a need for early vigilant eye exams for patients who undergo bariatric surgery, especially if they already have sight-threatening retinopathy."

As reported in the American Journal of Ophthalmology, Dr. Lee and colleagues searched the literature through March 2020 for studies comparing DR in patients who underwent bariatric surgery versus conventional medical management. Fourteen studies - two randomized controlled trials, 12 observational studies - involving more than 110,000 surgical and 253,000 controls were included; 73% of participants were women with a weighted mean age of 43. All participants had type-2 diabetes.

Surgical patients had a statistically significantly lower post-operative prevalence of all DR (rate ratio, 0.17) and sight-threatening DR (RR, 0.47).

Although early DR worsening and progression to sight-threatening DR had occurred more often in those with more severe DR initially, after the first year, bariatric surgery resulted in significantly fewer patients with worsened DR (RR, 0.29).

The overall risk of bias was low; and the evidence was of low-to-moderate certainty.

Dr. Rohit Soans, Medical Director of Bariatric Surgery at Temple University Hospital in Philadelphia, commented by email to Reuters Health, "It is not surprising that there was a significant long-term reduction in DR progression. Bariatric surgery does correct hyperglycemia quickly and this may have an effect on specifically proliferative DR."

"I do think this article makes a case of screening for and staging patients with DR before bariatric surgery," he said. "It would likely be best to make sure that patients with proliferative DR have very close follow up during the first year after surgery."

"Microvascular and inflammatory changes after bariatric surgery are an area of intense interest to us and there will be much more research on these topics in the next few years," he added. "Understanding the mechanisms that are fueling (these) observations will be a very important next step."

SOURCE: https://bit.ly/3qLbatm American Journal of Ophthalmology, online January 8, 2021

By Marilynn Larkin



Posted on 23 January, 20211 February, 2021