Accommodative lag and refractive error in infants and toddlers.

PURPOSE: To measure accommodative performance as a function of refractive error in very young children.

METHODS

This was a prospective study of accommodation lag in multiethnic typically developing children ages 5 to 24 months. Accommodation lag was measured by means of a modified bell retinoscopy technique. Refraction was measured by cycloplegic retinoscopy, and right and left eye results were averaged. The study compared accommodative performance to cycloplegic spherical equivalent and astigmatic refractive error.

RESULTS

Analysis of data from 189 of 203 subjects revealed that larger lags and lower gain of the accommodative response were more common in younger children, although most children of all ages accommodated well, with 95% having lags <1.25 D. Larger accommodation lags were associated with greater spherical equivalent refractive error, although only with hyperopia ≥4.0 D were lags ≥1.25 D observed in a majority of children. Larger lags in the more hyperopic meridian were seen with increasing hyperopic with-the-rule astigmatism, but lag in the more hyperopic meridian varied little with the amount of myopic or mixed astigmatism.

CONCLUSIONS

Most 5- to 24-month-old children accommodate well over a range of moderate hyperopic refractive errors, but hyperopia ≥4.0 D is rarely associated with normal accommodative performance. Hyperopic and mixed or myopic astigmatic children show different patterns of accommodation, which may explain the patterns of visual acuity deficits seen in these children.