The prevalence of obesity in kids has risen dramatically over the past few decades, and a new study suggests it may increase the risk of developing keratoconus. “Overweight and obese adolescents have higher odds for having keratoconus compared to normal weight,” the investigators wrote in their paper.

This cross-sectional, population-based study included 579,946 males and females aged 16 to 19.9 years. The participants were divided into four groups based on their BMI: underweight (8.3%), normal weight (73.9%), overweight (10.7%) and obese (7.1%).

The team observed keratoconus in 164 cases per 100,000. They noted a greater prevalence of keratoconus among the obese group (270 per 100,000) than the overweight (179 per 100,000), normal weight (154 per 100,000) and underweight (141 per 100,000) groups. In comparison with adolescents of a normal weight, the odds ratios for obese, overweight and underweight adolescents were 1.50, 1.42 and 0.84, respectively, after adjusting for gender, age, height, country of origin and socioeconomic status.

“This study provides strong evidence regarding the independent association between BMI and keratoconus,” the study authors concluded. “BMI should be considered as a risk factor for keratoconus, and further research should elucidate how obesity is involved in the progress of keratoconus.”

Eliasi E, Bez M, Megreli J, et al. The association between keratoconus and body mass index: a population-based cross-sectional study among half a million adolescents. Am J Ophthalmol. December 9, 2020. [Epub ahead of print].