Mortality and Causes of Death Among Individuals With Keratoconus

Abstract

Purpose: The purpose of this study was to determine whether there is an increased risk of mortality among individuals with keratoconus. Methods: This was a retrospective, case-control study using the Utah Population Database. Cases were defined as individuals diagnosed with keratoconus from 1996 to 2020 and were matched 5:1 with controls on birth year, sex, whether born in Utah, and follow-up time in Utah. Individuals diagnosed with trisomy 21 or connective tissue disease were excluded. Main outcome measures were the all-cause and cause-specific mortality among keratoconus cases compared with matched controls. Cox regression models were used, additionally adjusting for race and ethnicity. Results: A total of 7847 keratoconus cases and 38,597 controls were studied in the final analyses. The mean age at index diagnosis was 43 ± 17 years, and mean age at last follow-up was 54 ± 17 years for both cases and controls. At last follow-up, 92% of cases were living compared with 91% of controls. After adjusting for covariates, there were no significant differences in all-cause mortality (P = 0.161), mortality from natural causes (0.222), or mortality from unnatural causes (P = 0.494) between cases and controls. When analyzed according to specific causes of death, keratoconus cases had a higher mortality risk from diseases of the nervous system and sense organs compared with their matching controls (hazard ratio 1.59; 95% confidence interval, 1.19–2.11; P = 0.002). Conclusions: There was no evidence of an increased risk of mortality among individuals with keratoconus. There may be an increased risk of death due to diseases of the nervous system and sense organs among individuals with keratoconus.