Purpose: To examine the relationship of increased ocular asymmetry over time to vision-related quality of life in keratoconus.
Methods: The subjects were from the Collaborative Longitudinal Evaluation of Keratoconus Study and had complete data on a least 1 scale of the National Eye Institute Visual Function Questionnaire and examination data at baseline and at least 1 follow-up visit. Three measures of disease asymmetry [visual acuity (VA), corneal curvature, and refractive error] and better eye status were assessed. Multilevel models were fit to the data.
Results: The analyses were completed using the data from 961 subjects. Six scales on the National Eye Institute Visual Function Questionnaire had adequate variability to the model (distance activity, driving, mental health, near activity, ocular pain, and role difficulties). Refractive error changes were not associated with statistically significant quality-of-life differences. Except for ocular pain, statistically significant, but not clinically meaningful, differences were found for VA changes and corneal curvature changes. For a 0.1-unit logarithm of the minimum angle of resolution of VA change, the quality-of-life scales decreased between 0.20 and 0.99 units. For a 1.00-diopter steepening of corneal curvature, these decreases were on the order of 0.20 to 0.59 units. Changes related to asymmetry were small as well; decreases were on the order of 0.20 to 0.38 units.
Conclusions: Increasing ocular asymmetry and decreases in VA and corneal steepening in the better eye were associated with decreasing vision-related quality of life, although the magnitudes of the changes were not clinically meaningful. Of these 2 disease status indicators, the vision in the better eye had greater effect on the vision-related quality of life.
*College of Optometry, The Ohio State University, Columbus, OH
†Washington University School of Medicine, St Louis, MO.
Reprints: Lisa A. Jones-Jordan, College of Optometry, The Ohio State University, 649 Fry Hall, 338 West 10th Avenue, Columbus, OH 43210 (e-mail: email@example.com).
Supported by National Eye Institute/National Institutes of Health grants EY10419, EY10069, EY10077, EY12656, and EY02687, Conforma Contact Lenses, Paragon Vision Sciences, CIBA Vision Corporation, and the Ohio Lions Eye Research Foundation.
The authors have no conflicts of interest to disclose.
Clinical centers and members of the CLEK Study Group are listed in Appendix 1 (Supplemental Digital Content 1, http://links.lww.com/ICO/A79).
Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.corneajrnl.com).
Received October 24, 2011
Accepted March 19, 2012