Keratoconus Profile in the Elderly: Prevalence and Clinical Indices

To assess the prevalence and associated characteristics of keratoconus (KCN) among individuals aged 60 years and older.

In this study, total of 160 clusters and 20 strata were identified in Tehran, Iran through a multistage cluster sampling technique. Participants aged 60 years and older were included in the study. Corneal imaging used the Pentacam AXL. The diagnosis of KCN in this study was determined based on the measurements obtained from axial topography, pachymetry, and the elevation data from the Pentacam's refractive 4-maps.

The prevalence of KCN was determined to be 5.36% [95% confidence interval (CI), 4.52-6.2], with rates of 5.04% (95% CI, 3.88-6.2) in males and 5.68% (95% CI, 4.47-6.9) in females. The prevalence of KCN increased from 4.6% (95% CI, 3.29-5.92) among individuals aged 60 to 64 years to 6.92% (95% CI, 3.18-10.67) in those aged 80 years and older. A multiple regression analysis indicated that advancing age (odds ratio = 1.03; P < 0.001) and illiteracy (odds ratio = 1.65; P < 0.001) were significant factors associated with KCN in the elderly population. Besides, the predominant curvature pattern observed in KCN was the asymmetric bowtie with inferior steepening (18.91%), whereas the symmetric bowtie was the least common (0.29%).

The prevalence of KCN is notably high among the elderly population and tends to rise with advancing age. Findings from the current study underscore the critical role of corneal topography and tomography in guiding clinical decisions for older patients, particularly in the context of intraocular lens power calculations.