Accommodative Response in Astigmatic Children Aged 3 to <10 Years

Abstract

Purpose : Children typically have a small accommodative lag during near work. Studies characterizing the accommodative response in children with astigmatism are limited. The purpose of the current report is to determine whether children with low and high astigmatism accommodate closer to the least plus or most plus meridian, or to the circle of least confusion.

Methods : Children 3 to <10 years of age with habitually uncorrected refractive error viewed a 20/250 letter monocularly at 3D demand (33cm). Astigmatism was determined using cycloplegic autorefraction (Grand Seiko); accommodative responses (AR) were also measured using autorefraction. Astigmatism was classified as low (cylinder (cyl)≤1.50D) or high (cyl>1.50D). Children were included in analysis if both meridia had less than 3D of myopia such that the accommodative demand was >0D for the 3D stimulus. AR was classified based on the meridian in best focus relative to the 3D stimulus: least plus, most plus, or circle of least confusion (stimulus focused in the middle 1/3 of the two meridia). Chi-square analyses and Fisher’s exact test were used to compare the proportions of children who accommodated to least plus, most plus, or circle of least confusion.

Results : 309 children (89.6%) had low astigmatism (mean=0.50D; SD=0.35D) and 36 children (10.4%) had high astigmatism (mean=2.51D; SD=0.83D). Only 2 children (with low astigmatism) focused near the most plus meridian, thus this classification was removed from analysis. In the low astigmatism group, there were significantly more children classified as least plus (N=305, 99.3%) than as circle of least confusion (N=2, 0.7%; 𝜒²(1,N=307)=301.05, p<.001). Similarly, in the high astigmatism group, more children were classified as least plus (N=30, 83.3%) than as circle of least confusion (N=6, 16.7%; 𝜒²(1,N=36)=16.00, p<.001). Fisher’s exact test indicated that significantly more children with high astigmatism focused near the circle of least confusion than children with low astigmatism (p<.001).

Conclusions : Most children with habitually uncorrected refractive error accommodated closer to the least plus meridian for the near stimulus. Our data suggest that significantly more children with high astigmatism focused near the circle of least confusion compared with children with low astigmatism.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.