Study finds reduced risk of cataracts associated with obesity surgery

The risk of cataract development in obesity surgery patients compared to patients with obesity but no surgery increased with age: the lowest risk of cataract was observed in patients aged 40-49 years, where those who had obesity surgery were around half as likely to develop cataract compared to patients not having had obesity surgery. However, in patients aged 60 years or over, the beneficial effect seemed to disappear, with no significant difference in the risk of cataract between groups.

Furthermore, the authors observed that surgical techniques generally leading to higher weight loss and a higher risk of malabsorption of nutrients, such as duodenal switch or gastric bypass, were associated with the lowest risks of cataract (51% statistically non-significant decreased risk of cataract after duodenal switch, 32% statistically significant decreased risk of cataract after gastric bypass). Sleeve gastrectomy on the other hand, generally leads to slightly less weight loss and malabsorption of nutrients, and there was no difference in cataract risk between patients who underwent sleeve gastrectomy and those not undergoing bariatric surgery. The authors also observed no differences between sexes; both men and women yielded equally reduced cataract risk following bariatric surgery.

The authors conclude that "substantial weight loss is associated with a decreased risk of cataract, especially if obesity surgery was performed before age 60. This decreased risk is an addition to the multitude of positive effects that weight loss has on eye health. Furthermore, we observed a potential dose-response relationship between the amount of weight loss and reduction in cataract incidence."