Test–retest reliability of clinical accommodative measures in adolescents

ABSTRACT Purpose To determine long‐term (3 months) test–retest reliability of accommodative testing in adolescents with normal accommodative amplitude. Methods Participants aged 12 years to <17.5 years with normal accommodative amplitude (minimum of 11 diopters [D]) and binocular vision were enrolled. Three trials of monocular accommodative amplitude using the push‐up method and one trial of monocular accommodative facility with ±2.00 D flipper lenses were performed at the initial and 90‐day retest visits. Bland–Altman analyses of within‐participant differences between initial and 90‐day retest visits were performed. Results Ninety‐three participants (mean age 14.3 ± 1.6 years; 51% female) were enrolled, and 91 of 93 (98%) participants completed both visits. At the initial visit, the mean accommodative amplitude was 13.95 D and 14.32 D in the right and left eyes, respectively, and the mean accommodative facility was 10.16 and 10.19 cycles per minute (cpm) in the right and left eyes, respectively. Although no significant difference was observed in accommodative amplitude between the initial and retest visits, a significant but clinically small difference was observed in facility. The 95% limits of agreement were large for amplitude (right eye −3.96 to 3.63 D and left eye −4.92 to 4.13 D), particularly in those with initial amplitude exceeding 14 D, and for facility (right eye −6.43 to 9.44 cpm and left eye −7.54 to 10.8 cpm). Conclusions In adolescents with normal accommodative amplitude and binocular vision, test–retest differences in accommodative amplitude and facility were small; however, the variability was high, especially for accommodative facility.