A recent study revealed several previously unidentified risk factors associated with keratoplasty for keratoconus, including corneal hydrops, Leber’s congenital amaurosis and sleep apnea.

This retrospective, cross-sectional study assessed 42,086 keratoconus patients, of whom 1,282 (3.0%) had keratoplasty to treat the condition.

The team found that being of female sex (OR=0.87) and living in metropolitan areas (OR=0.75) were associated with lower odds of receiving keratoplasty. Compared with individuals aged 10 to 19 years, those aged 20 to 29 (OR=1.77) and 30 to 39 (OR=1.61) were more likely to have keratoplasty, while patients in the oldest age group studied (50 to 64) did not show statistically significant associations.

Conditions associated with higher odds of receiving keratoplasty were corneal hydrops (OR=4.87), Leber’s (OR=2.41), sleep apnea (OR=1.46), diabetes (OR=1.32) and depression (OR=1.22). Conditions associated with lower odds, on the other hand, were prior contact lens use (OR=0.61) and a history of glaucoma (OR=0.60).

Interestingly, geography was also a factor. Individuals residing in the Southeast (OR=3.02), the Midwest (OR=3.52), and the West (OR=3.52) had substantially higher odds of receiving keratoplasty compared to those in the Northeast. “We hypothesize that these trends may be associated with access to advanced contact lens fitting services and contact lens tolerability associated with different climates,” the authors noted in their paper. This hypothesis is supported by the observation that patients with prior contact lens usage had lower odds of undergoing keratoplasty, suggesting that access to contact lens fitting may reduce the need for keratoplasty for patients whose vision can be successfully rehabilitated.

Of the clinical attributes, the study authors concluded, “Future research should examine if young patients with these conditions may benefit from more frequent follow-up and/or early crosslinking to reduce the need for subsequent keratoplasty.”