The myopia epidemic is a major public health concern, yet the underlying causes and mechanisms of myopia progression remain unclear. Recent studies have reported an association between myopia progression and higher order aberrations (HOAs). However, to our knowledge, no research has reported the relationship between HOAs and environmental factors, which are well-established contributors to myopia progression. In this prospective study, we investigated this association across the COVID-19 pandemic. Children aged 6 to 12 years from one elementary school in Tokyo were enrolled. Non-cycloplegic refraction and ocular biometry were measured. Investigations were carried out every summer from 2018 to 2021. We adopted ocular spherical aberration (SA), third- and fourth-order aberrations (S3 and S4), and total HOAs (THOA) (calculated as the root mean squares from the third- to sixth-order Zernike coefficients) evaluated with a natural pupillary diameter. We analyzed 357 students during 2018 to 2019 (pre-pandemic period), 217 during 2019 to 2020 (pandemic period), and 285 during 2020 to 2021 (post-pandemic period). The time spent outdoors decreased significantly from 100.5 min/day in 2018 to 66.2 min/day in 2020 (p < 0.001). The time spent on near work including digital device usage initially decreased and then increased during the observation period. The time spent on smartphones was correlated inversely with the changes in S3, S4, and THOA in the pre-pandemic period. During the pandemic, the time spent on computers was correlated positively with the changes in the SA, S3, S4, and THOA. In the post-pandemic period, the time spent on reading and studying was correlated positively with the changes in THOA. Remarkably, the outdoor time was not a significant variable during any period. In conclusion, lifestyle factors changed dramatically throughout the pandemic and, particularly near work, may have been associated with the HOAs in children.
Shimizu et al. (Fri,) studied this question.