Original article
Changes in the Quality-of-Life of People with Keratoconus

https://doi.org/10.1016/j.ajo.2007.11.017Get rights and content

Purpose

The Collaborative Longitudinal Evaluation of Keratoconus Study (CLEK) previously showed that people with keratoconus report significantly impaired vision-related quality-of-life (V-QoL), as measured on the National Eye Institute Visual Function Questionnaire (NEI-VFQ), similar to that of people who have severe macular degeneration. For this study, we evaluated changes that occurred in V-QoL over seven years of follow-up.

Design

In this prospective cohort study of 1,166 participants followed up for seven years, we estimated change in V-QoL by projecting the slope of a minimum of three reports on 11 scales of the NEI-VFQ. Correlation with clinical indicators was evaluated, and differences were assessed between those who had clinically significant changes in clinical factors and those who did not. Logistic regression was used to assess factors associated with a decline in 10 points or more in a scale score over seven years.

Results

All scales showed modest decline except ocular pain and mental health. Baseline factors were not associated with longitudinal change in NEI-VFQ scores. A 10-letter decline in high-contrast binocular visual acuity or a 3.00-diopter increase in corneal curvature were associated with significantly larger declines in V-QoL. In multivariate analysis, these factors also were found to be associated with a 10-point decline in NEI-VFQ scale scores.

Conclusions

Keratoconus is associated with significantly impaired V-QoL that continues to decline over time. For a substantial plurality of patients, these declines are significant.

Section snippets

Methods

The CLEK study is a multicenter, observational study designed to assess the natural history of keratoconus. Details of the CLEK study and its enrollment criteria have been presented elsewhere.2 We enrolled 1,209 patients and completed eight years of follow-up. The institutional review board of each participating clinic approved the CLEK protocol, and all subjects signed informed consent documents before enrollment.

All CLEK patients completed an annual examination to assess visual acuity and

Results

Of the 1,209 CLEK patients, 925 (76%) met the criteria for inclusion in these analyses. The demographic characteristics of these patients are provided in Table 1, and the clinical characteristics are detailed in Table 2.

The unadjusted mean slopes (Table 2) show that, on average, patients with keratoconus perceive a decline in V-QoL on all scales except ocular pain and mental health. Extrapolating the annual slope to the seven-year follow-up period of CLEK indicates that the average decline on

Discussion

Over seven years, CLEK participants, on average, reported a decline in their V-QoL as measured by most NEI-VFQ scales. On scales for which a decline was seen, the decline was modest (see Table 2), ranging from less than one point over seven years (general vision) to almost two points (near activities). The exceptions to this were dependency, which declined considerably, and mental health and ocular pain, which improved. In both cases, we suspect that these were examples of changes in extreme

Dr Steven Kymes is a Research Assistant Professor in the Department of Ophthalmology and Visual Sciences at Washington University School of Medicine, where he is an Assistant Director of the Vision Research Coordinating Center and a Senior Fellow in the Center for Health Policy. Prior to entering academic life, Dr Kymes held various management and marketing positions with health care and managed care organizations. Dr Kymes’ research interests concern cost-effectiveness of medical treatment and

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Dr Steven Kymes is a Research Assistant Professor in the Department of Ophthalmology and Visual Sciences at Washington University School of Medicine, where he is an Assistant Director of the Vision Research Coordinating Center and a Senior Fellow in the Center for Health Policy. Prior to entering academic life, Dr Kymes held various management and marketing positions with health care and managed care organizations. Dr Kymes’ research interests concern cost-effectiveness of medical treatment and testing, assessment of health-related quality-of-life, and the relationship between insurance plan design and health outcomes.

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