Validity, reliability, and repeatability of the useful field of view test in persons with normal vision and patients with glaucoma.

ABSTRACT

PURPOSE: To determine the validity, test-retest reliability and repeatability of the UFOV test in healthy controls and glaucoma patients. METHODS: Three substudies with the UFOV test were conducted (1) validity was evaluated in 77 older controls (mean age 64 [SD, 7] years) and 53 glaucoma patients (mean age 69 [SD, 8] years); (2) test-retest reliability was evaluated in 13 young controls (mean age 28 [SD, 4] years), 21 older controls (mean age 66 [SD, 9] years), and 22 glaucoma patients (mean age 68 [SD, 8] years) who performed the test twice within approximately two weeks; (3) repeatability was evaluated in 17 young controls (mean age 33 [SD, 8] years) who performed the test five times on the same day. RESULTS: In the validity substudy, mean total processing time was significantly less for older controls (358.3 ms [SD, 226.8 ms]), than glaucoma patients (580.2 ms [SD, 324.5 ms]), with moderate correlations (rho ≥ 0.40) between total processing time and age, and visual field impairment. In the reliability substudy, mean total processing time was significantly less on retest (P ≤ 0.02), with glaucoma patients showing the largest mean test-retest difference (144.7 ms [SD, 168.9 ms]) compared with young (31.5 ms [SD, 43.7 ms]) and older controls (56.2 ms [SD, 74.8 ms]). The 95% limits of agreement were significantly wider for glaucoma patients (-186.3 and +475.7 ms) compared with young (-54.1 and +117.1 ms) and older controls (-90.5 and +202.9 ms), (P < 0.01). In the repeatability substudy, performance remained constant after the second of five tests (differences in mean total processing time <6 ms). CONCLUSIONS: Measurement properties of the UFOV test are important for assessing functional performance, in particular, fitness to drive. Our results indicate moderate variability, greater for glaucoma patients than healthy controls, and a learning effect. Two consecutive tests are suggested to establish reliable baseline measures.