Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study: methods and findings to date

Area of Science:

• Ophthalmology
• Corneal Diseases
• Vision Science

Background:

• Keratoconus is a progressive corneal disease affecting vision.
• Longitudinal data on keratoconus progression and its impact on quality of life are crucial for patient management.

Purpose of the Study:

• To describe baseline and longitudinal findings of the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study.
• To characterize changes in vision, corneal curvature, corneal status, and vision-specific quality of life over 8 years.

Main Methods:

• An 8-year, multi-center, natural history study involving 1209 patients with keratoconus.
• Annual examinations assessing visual acuity, corneal topography, corneal health, and quality of life using the National Eye Institute Visual Function Questionnaire.

Main Results:

• A mean decrease in best-corrected visual acuity (high and low contrast) was observed over 7 years.
• Corneal curvature increased by an average of 1.60D over 8 years, with 24% showing increases of 3.00D or more.
• The 8-year incidence of corneal scarring was 20%, with younger age, corneal staining, steeper baseline curvature, contact lens wear, and poorer low-contrast acuity as predictors.
• Keratoconus significantly impacted vision-specific quality of life, disproportionate to its prevalence and severity.

Conclusions:

• Clinicians can predict keratoconus progression by identifying predictive factors in individual patients.
• Understanding these factors aids in managing the disease course and patient outcomes.