Purchase this article with an account.
Tawna L Roberts, Julia S. Benoit, Ruth E Manny, Scott B Stevenson, Heather A Anderson; Accommodative Accuracy and Stability In Passive and Active Viewing Tasks in Children with Uncorrected Hyperopia. Invest. Ophthalmol. Vis. Sci. 2016;57(12):3956. doi: https://doi.org/.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The purpose of this study was to investigate accommodative accuracy and stability in young children with uncorrected hyperopia and adults as control subjects.
Accommodation was measured using photorefraction (25 Hz) in 54 children (3-10 yrs) with uncorrected hyperopia and age normal VA and binocular vision and in 8 adults (23-31 yrs) with normal VA without correction. Subjects viewed 20/50 sized stimuli at 33cm during a 10 minute active and passive task (order randomized). Active task: Subjects <6 yrs and 6 yr olds unable to read, viewed shapes while answering questions about the shapes (Group 1, n = 31). Subjects ≥6 yrs read passages at their reading level and answered questions upon completion (Group 2, n = 23). Adults read portions of an economics dissertation and answered questions upon completion. Passive task: Group 1 viewed shapes, Group 2 and adults viewed rows of letters. Mean accommodative lag and stability (in the time [root mean square RMS] and frequency domain [low frequency component (LFC) 0-<0.6Hz]), were calculated. Two-factor repeated measures ANOVA with post hoc analysis (Holm Sidek) compared accommodation within and across groups for both viewing conditions.
Both groups of children had larger lags (p<0.05), RMS (p<0.001) and LFC (p<0.001) in the passive versus active condition. A difference in lag was not detected in adults between the two conditions (p=0.99), but RMS (p=0.030) and LFC (p=0.003) were significantly larger during passive viewing. Group 1 had significantly larger lags than Group 2 (p=0.008) and adults (p=0.005) for the passive condition and larger lags than Group 2 (p=0.039), but not than adults (p=0.137) for the active condition. A difference in lag was not detected between Group 2 and adults in either task (p>0.05). RMS and LFC decreased significantly across groups in order of increasing age for both tasks (p<0.05), with the exception that Groups 1&2 had similar RMS in the active task (p=0.144).
These data suggest that on average, the accommodative response is less accurate and more variable in children when passively viewing a stimulus than when actively viewing a stimulus. Additionally, for the majority of comparisons, children <10 yrs with uncorrected hyperopia did not have adult-like accommodative behavior (accuracy or stability) under passive or active viewing.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.
This PDF is available to Subscribers Only