Corneal scarring and vision in keratoconus - A baseline report from the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study

Purpose, The multicenter Collaborative Longitudinal Evaluation of Keratocon us (CLEK) Study is a prospective, observational study of 1,209 keratoconus patients. We report on the correlation of corneal scarring with clinical an d patient-reported variables at the baseline visit. Methods. Patients compl eted a questionnaire on their vision, effect of glare, contact lens wear, a nd work-related issues. Clinical examination included high- and low-contras t visual acuity, refraction, assessment of corneal scarring by the clinicia n and by photography, and measurement of corneal curvature. The correlation of central corneal scarring with visual acuity and patient-reported variab les was analyzed using multiple regression analysis and generalized estimat ing equations. Results. High- and low-contrast visual acuity with habitual and optimal correction is reduced in scarred eyes. Multiple regression anal yses controlling for age, contact lens wear, and disease severity show that central scarring is associated with poorer visual acuity and increased pat ient-reported symptoms of glare. Restrictions on day-to-day activities do n ot appear to be associated with corneal scarring above and beyond the effec ts of keratoconus alone. Conclusions. Corneal scarring in keratoconus is si gnificantly associated with decreased high- and low-contrast visual acuity.