Preschool children with insufficient physiological hyperopia experience accelerated myopic drift.

Significance: This study reveals that preschool children with insufficient physiological hyperopia experience accelerated myopic drift and axial length elongation. Regular monitoring can serve as an early warning for impending myopia during early childhood, highlighting its critical role in future myopia prevention strategies.

Purpose: This study examines the patterns of spherical equivalent and biometric parameters if physiological hyperopia has shown an accelerated tendency to regress by preschool age and whether the early onset of physiological hyperopia regression accelerates myopia onset.

Methods: This kindergarten-based longitudinal observational study included 1308 children between 3 and 6 years old from kindergartens in Haidian District, Beijing, China. Comprehensive eye examinations were performed on all participants.

Results: Two grouping methods were used for all children. The first was based on their baseline age and divided into four groups of 3 to 6 years. The second was based on spherical equivalent, with spherical equivalent >0.75 D designated as the physiological hyperopia group and spherical equivalent ≤+0.75 D designated as the pre-myopia or myopia group. Physiological hyperopia and the proportion of children with physiological hyperopia displayed a declining trend over time in all age groups (p<0.001), with the older the baseline age, the more pronounced the decline (p<0.001), and the rate increased year by year (p<0.001). In contrast, axial length, anterior chamber depth, and axial length/corneal curvature radius displayed an increasing trend (p<0.001), and the rate of increase of axial length and anterior chamber depth accelerated over time (p<0.001). Female children have more physiological hyperopia and a higher proportion of children with physiological hyperopia compared with males (p<0.001) but displayed a more rapid decline (p<0.001). The axial length, anterior chamber depth, and the axial length/curvature radius were found to be elevated in the pre-myopia or myopia group in comparison to the physiological hyperopia group (p<0.001). Furthermore, the magnitude of the rate increase in myopic drift and axial length was found to be greater in the aforementioned group.

Conclusions: The regression of physiological hyperopia accelerates in preschool-age children, with older children showing faster regression and lower levels of physiological hyperopia. This premature decline correlates with an increased rate of myopic drift and accelerated biometric growth. Therefore, regular monitoring of physiological hyperopia should begin at preschool age, as the rate of regression serves as a more reliable predictor of future myopia than refraction alone.