Purchase this article with an account.
K. Zadnik, B.S. Wilson, M.O. Gordon, CLEK Study Group; Age in Keratoconus . Invest. Ophthalmol. Vis. Sci. 2006;47(13):2951.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Conventional clinical wisdom has long held that younger age at keratoconus onset was associated with worse disease, faster disease progression, and/or a shorter time to penetrating keratoplasty. The purpose of this analysis was to evaluate age as a factor in severity–related outcomes in keratoconus among patients in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study.
Up to 1,065 keratoconus patients enrolled in the CLEK Study were evaluated for associations between younger age and the following outcomes after up to eight years of annual follow–up: incident corneal scarring, penetrating keratoplasty, change in visual acuity, and change in corneal curvature (first definite apical clearance lens [FDACL]).
In univariate analyses, younger age at baseline was associated with a higher incidence of corneal scarring. In patients 19 years old or younger, 35.7% had at least one scarred cornea by year 5 (10/28 patients) compared with 12.9% of patients 20 years old or older (110/850 patients) (p=0.001). Likewise, younger age at baseline was associated with a higher incidence of penetrating keratoplasty among unoperated eyes at CLEK Study baseline. The eight–year incidence of penetrating keratoplasty was higher (15%) among patients 40 years old or younger compared to patients 40 years old or older (8%). There was no difference in the slope of the change in either high– or low–contrast visual acuity as a function of younger age, but younger eyes demonstrated a greater slope of the change in corneal curvature. Multivariate analyses revealed a significant association between five–year incident scarring in patients younger than 20 years old (odds ratio = 6.34; 95% confidence interval = 2.57, 15.00, p<0.001) when controlling for corneal staining, corneal curvature, and contact lens wear and a significant association between eight–year incident penetrating keratoplasty and younger age (odds ratio = 0.72 for every decade younger; 95% confidence interval 0.58, 0.89; p=0.003) when controlling for high–contrast, best–corrected visual acuity and corneal curvature. No significant association between visual acuity and younger age was evident with multivariate analysis, but there was a significant association between younger age (less than 35 years old) and corneal curvature (FDACL) (odds ratio = 2.45; 95% confidence interval 1.82, 3.30; p<0.0001.
Younger age appears to be associated with the development of corneal scarring, penetrating keratoplasty, and corneal steepening in patients with keratoconus.
This PDF is available to Subscribers Only