Effect of astigmatism on refraction in children with high hyperopia

The aim of this study was to evaluate primitively whether the extent and component of astigmatism influences regression in degree of spherical (DS) and the best corrected visual acuity (BCVA) of children with hyperopia of +5.00 diopters (D) or greater. Children were screened from the outpatient refraction database in the Wenling No. 1 People's Hospital in Zhejiang province and in Eye & ENT Hospital of Fudan University between June 2005 and December 2015. Eligible eyes were divided into three groups according to the extent of astigmatism: group of astigmatism <= -2 D of cylinder, group without astigmatism or with astigmatism >= -0.5 D of cylinder, and the group with astigmatism >= -0.75 D and <= -1.75 D of cylinder. For the component of astigmatism, eyes with astigmatism as <= -0.75 D of cylinder were divided into 3 groups: with the rule (WTR), against the rule (ATR) and the group with the oblique. Differences in the changes of BCVA and refractive error (RE) during follow-up terms were compared within and among groups. Differences in the mean DS or BCVA were not statistically significant between groups according to the extent of the astigmatism at the last visit (p = 0.2396 and p = 0.2131, respectively). As for the component of astigmatism, the group with oblique astigmatism had more severe hyperopia than the group of WTR (p < 0.0001) and mean BCVA in the group of ATR were better than that of the other two groups (p < 0.0001) at the first visit. However, the among-group changes were not significant at the end of the observation (p > 0.1). The regression of DS and improvement of the BCVA in children with hyperopia of +5.00D or greater may be irrespective of the component and the extent of astigmatism.