Effect of spectacle lenses with highly aspherical lenslets on changes in peripheral eye length and asymmetry

Purpose: Spectacle lenses with highly aspherical lenslets (HAL) have been shown to slow myopia progression and axial length (AL) elongation effectively. The effects of HAL on peripheral eye length (PEL) and peripheral refraction (PR) were investigated in children who continued wearing HAL or switched from single-vision spectacle lenses (SVL) or spectacle lenses with slightly aspherical lenslets (SAL) to HAL. Methods: Fifty-two participants who had worn HAL for 2 years continued their use (HAL group), while 51 and 48 participants who had originally worn SAL or SVL for 2 years switched to HAL (SAL-HAL and SVL-HAL groups, respectively) in Year 3. A new SVL group of 56 participants, 10-15 years of age, was enrolled in Year 3 (new-SVL group). PEL and PR were measured every 10 degrees from 30 degrees nasal to 30 degrees temporal and from 30 degrees superior to 10 degrees inferior retina. Results: There were significant differences in the changes in AL and PEL on the temporal side among the groups (all p <= 0.001). All three HAL groups exhibited less elongation than the new-SVL group. PR changes in the parafoveal temporal (p = 0.002) and superior (p = 0.001) regions differed among the groups; the new-SVL group progressed more than the other three groups. The AL in the new-SVL group exhibited greater elongation than the PEL (all p < 0.02). However, there were no significant differences between the AL and PEL changes in the three HAL groups (all p > 0.05). Conclusions: Compared with wearing SVL, switching to or continuing to wear HAL could slow central and temporal elongation of eye length. Wearing HAL could impact retinal steepness and symmetry.