Abstract
Purpose :
The purpose of this 6-year cohort study was to investigate the patterns of physiological growth of axial length (AL) in myopic eyes among children and teenagers, and to determine the thresholds of physiological AL growth to differentiate between progressive myopia and non-progressive myopia.
Methods :
A total of 1181 children, aged 7 to 18 years, residing in Guangzhou, China, were longitudinally followed for 6 years. Annual data on ocular biometry, cycloplegic refraction, and demographics were collected. All the subjects were divided into four refractive categories: Persistent Emmetropia (PE), Emmetropia to Myopia (EM), Progressive Myopia (PM), and Non-Progressive Myopia (NMP).
Results :
The study found that the mean annual changes in AL were similar between the PE group and the NMP group in children aged 7 to 9 years. However, for individuals aged 10 to 12 years, both AL and spherical equivalent refraction (SER) progressions were significantly higher in the EM, PM, and NMP groups compared to the PE group (all P<0.001). The slope of the AL growth curve in the NMP group was similar to that of the PE group, with no statistically significant difference (P=0.610). The study also observed a strong association between the change in AL and the rate of height growth before 15 years of age across all four groups. Additionally, the number of myopic parents was found to be associated with AL progression within the EM group (P<0.001). The study identified indicative thresholds of 0.16 mm and 0.15 mm for individuals with emmetropia and those initiating with myopia, respectively, to signify physiological AL growth.
Conclusions :
This study reveals consistent patterns of axial elongation in persistently emmetropic eyes and non-progressively myopic eyes among children and teenagers. The similarities in the thresholds for physiological AL growth between these two refractive profiles highlight the importance of physiological axial length growth in maintaining optimal refractive conditions, even in myopic eyes. These findings provide valuable insights for the development of effective myopia control strategies.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.