Purpose: To report on the development and validation of a short form of the Contact Lens Dry Eye Questionnaire (the CLDEQ-8) to enable it to reflect status of and change in overall opinion ("opinion") of soft contact lenses (SCLs).
Methods: Item reduction for the CLDEQ was achieved by correlation with overall opinion of SCLs at follow-up visits in a sample of 38 SCL wearers at one academic clinical site. The CLDEQ-8 score (frequency plus late day intensity of dryness, discomfort, and "blurry vision"; frequency of "closing eyes to rest them" and "removing CLs to relieve discomfort") was then tested in 379 SCL wearers in a multicenter study with analysis stratified by opinion ratings at baseline and 2 weeks postrandomization to new silicone hydrogel SCLs. The sum of CLDEQ-8 scores (maximum 37) was correlated with opinion by Spearman's rank correlation coefficient and analyzed for change in opinion by analysis of variance (ANOVA).
Results: The CLDEQ-8 scores in the validation sample were highly correlated with habitual baseline opinion (-0.44, p < 0.0001) and responsive to change in opinion postrandomization (-0.58, p < 0.0001). Baseline CLDEQ-8 scores by opinion status were as follows: Fair: 17.4 ± 8.7, Good 13.7 ± 6.4, Very Good 9.1 ± 4.7, and Excellent 6.4 ± 3.7 (ANOVA, F = 291.1, p < 0.0001). After 2 weeks, change in CLDEQ-8 scores by improvement status was as follows: Much Improved: -16.7 ± 10.0, Unchanged: -2.3 ± 5.0, to Much Worse +8.5 ± 5.8 (ANOVA, F = 16.5, p < 0.001).
Conclusions: The CLDEQ-8 score significantly reflected baseline status and change in overall opinion after refitting with two types of silicone hydrogels. The CLDEQ-8 score is a valid outcome measure in SCL clinical trials to reflect opinion of SCLs.