title: A case-comparison of intermittent exotropia and quality of life measurements.
abstract: A Vision Quality of Life Questionnaire that combines the SF-20 and a Vision Quality Scale developed by the authors was pilot tested in a case-comparison of extreme groups, patients with intermittent exotropia (IXT) and those with no vision problems (Non-IXT), at the University of Houston (UH) Optometry Clinic. The purposes of the study were to measure the internal consistency reliability and examine the validity-related evidence of vision function associated with the instrument. The pilot study involved mailing the instrument to 52 patients in each group (IXT and Non-IXT patients). IXT patients were then frequency-matched by age and separately by sex, to control for confounding variables, to Non-IXT group patients. The Cronbach's Alpha internal consistency reliability of both scales was acceptable at > 0.70 for both the IXT and Non-IXT groups. The Wilcoxon signed ranks test was used to determine validity-related evidence. The differences between groups on the SF-20 (p = 0.0276) and Vision Function Scale (VFS) (p = 0.0385) confirm that the scales discriminate between IXT and Non-IXT populations. Two conclusions can be drawn from the pretesting and pilot testing of the SF-20 and the VFS: (1) both have acceptable internal consistency reliability scores, and (2) both show validity-related evidence that they can discriminate vision function between IXT and Non-IXT patient populations.
authors.affiliation: University of Houston, College of Optometry, Texas, USA.
authors.forename: C
authors.initials: C
authors.lastname: McKeon
authors.forename: B
authors.initials: B
authors.lastname: Wick
authors.forename: L A
authors.initials: LA
authors.lastname: Aday
authors.forename: C
authors.initials: C
authors.lastname: Begley
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D005099:Exotropia / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011788:Quality of Life; D011897:Random Allocation; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014785:Vision, Ocular / Q000502:physiology*