Influence of Astigmatism Type on Myopia Progression Among Children Wearing Defocus Incorporated Multiple Segments...

This study aimed to retrospectively analyse two datasets to investigate the correlation between progressive myopia and astigmatism focusing on the influence of the type of astigmatism on myopia progression in children undergoing myopia management with Defocus Incorporated Multiple Segments (DIMS) spectacle lenses.

Retrospective right eye data from two anonymised datasets were obtained for analysis: an Asian paediatric population, and a Caucasian paediatric population. Participants' refractive error at baseline was classified into one of four categories: spherical, with-the-rule (WTR), oblique or against-the-rule (ATR) astigmatism. Myopia progression was evaluated by the change in Spherical Equivalent Refraction (SER) and Axial Length (AL) between baseline and follow-up visits.

Retrospective analyses were conducted on right eye data from 265 children (160 Asian & 105 Caucasian). Linear Mixed Models (LMM) analysis of the combined datasets (n = 184) demonstrated a statistically significant main effect of astigmatism type on longitudinal patterns on SER change (p < 0.001), interaction between time and astigmatism was not significant (p = 0.07). In contrast, the LMM resulted in no statistically significant main effect of the astigmatism types on AL change (p = 0.06). The interaction term between time and astigmatism type also did not reveal a statistically significant effect on AL change (p = 0.21). This indicates that the trajectory of myopia progression over time was comparable across all groups despite initial differences at baseline. Analyses revealed that WTR-astigmatism was associated with the least myopia progression and ATR-astigmatism was associated with the greatest progression in this study. The presence of astigmatism at baseline did not significantly affect myopia progression in children wearing DIMS spectacles.

The type of astigmatism affected myopia progression. Participants with WTR-astigmatism wearing DIMS spectacles showed less myopia progression compared to participants with oblique or ATR-astigmatism. Long-term investigations in participants with different types of astigmatism undergoing myopia management are required to better understand the relationship between progressive myopia and astigmatism type.