Effect of Spectacle Lenses with Highly Aspherical Lenslets on Binocular Vision and Accommodation in Myopic Children with and without Intermittent Exotropia

Abstract

Purpose. To evaluate the influence of spectacle lenses with highly aspherical lenslets (HAL) on binocular vision and accommodation in myopic children with intermittent exotropia (IXT) and compare the changes after wearing HAL in binocular vision and accommodation in myopic children with or without IXT. Method. Forty myopic subjects aged 8–12 years were recruited: 20 with IXT and 20 visually normal children. Stereoacuity, phoria, accommodative facility, fusional vergence, vergence facility, near point of convergence, amplitude of accommodation, and accommodative response (AR) were measured by wearing HAL or single vision spectacle lenses (SVL) in a random order after adapting for 20 minutes. Accommodative microfluctuation (AMF) was defined as the standard deviation of AR. Changes in binocular vision and accommodation after wearing HAL were compared between the two groups. Results. No significant differences were found in binocular vision after wearing HAL versus SVL in either group (all $P>0.05$ ). A greater AMF was found after wearing HAL than after wearing SVL in both groups (0.04 D, 95% confidence interval (CI), 0.03 to 0.05 D, $P<0.001$ for the IXT group; 0.05 D, 95% CI, 0.03 to 0.07 D, $P<0.001$ for the visually normal group); however, the other accommodation parameters did not change significantly (all $P>0.05$ ). There were no differences in the changes after wearing HAL in any parameter between the two groups (all $P>0.05$ ). Conclusion. HAL did not significantly change the binocular vision and accommodation for myopic children with or without IXT except for AMF in the short term.