Longitudinal Changes in Lens Thickness and Lens Power Among Persistent Non-Myopic and Myopic Children

Abstract

Purpose: To assess the longitudinal changes in crystalline lens in persistent non-myopic and myopic children. Methods: Four cohorts of children were recruited from Guangzhou, China, from first year of kindergarten (G0, n = 1129), first year of primary school (G1, n = 1324), fourth year of primary school (G4, n = 1854), and first year of junior high school (G7, n = 867) in 2018 and followed up annually for 2 years. All children received cycloplegic autorefraction and ocular biometry measurement. Children were classified into categories of persistent non-myopia (PNM; spherical equivalent refraction [SER] ≥-0.5 diopter [D] at baseline and during follow-up), persistent myopia (PM; SER <-0.5 D at baseline and during follow-up), or newly developed myopia (NDM: SER ≥-0.5 D at baseline and <-0.5 D during follow-up). Results: The mean (SD) age was 3.69 (0.34) years for children in G0, 6.79 (0.35) years in G1, 9.52 (0.42) years in G4, and 12.56 (0.38) years in G7. A LOWESS plot showed a three-stage pattern of change in lens thickness (LT) in PNM children including a rapid decrease from 3 to 7 years of age and a slower decrease from 7 to 11 years, followed by an increase thereafter. Similar trends were observed in the PM and NDM groups, although there was less change in LT. In contrast, lens power (LP) decreased consistently in all cohorts during the follow-up. No significant changes in LT or LP were observed around myopia onset. Conclusions: The lens showed a three-stage pattern of change in LT, whereas there was continuous loss of LP in children ages 3 to 15 years.