Age and initial spherical equivalent influence the axial length elongation in children aged 9-17 years undergoing orthokeratology therapy.

BACKGROUND

Orthokeratology (Ortho-K) lenses are increasingly used in children to manage myopia by reshaping the cornea and potentially influencing axial length changes. This study investigated factors affecting axial length changes in children aged 9-17 years wearing Ortho-K lenses, focusing on age, initial spherical value, and other parameters.

METHODS

This retrospective analysis included 84 children (49 males, 35 females, aged 9-17 years) who wore Ortho-K lenses at the Tenth Affiliated Hospital of Southern Medical University between January 2018 and December 2019, with a minimum follow-up of 12 months. Subjects met specific inclusion criteria, including myopia ≤ 6.00 DS and astigmatism ≤ 1.75 DC. Comprehensive ocular examinations were conducted, and axial length changes were measured using an IOL-Master500.

RESULTS

Univariate analysis revealed significant factors influencing axial length changes, including age (F = -5.476, P < 0.001) and initial equivalent spherical value (F = 8.314, P = 0.004). Mixed-effects model analysis confirmed that the duration of lens wear (mean: 18.3 ± 5.4 months), age, initial spherical lens value, and initial axial length significantly impacted axial length (P < 0.05). The mean axial length elongation was 0.18 ± 0.09 mm/year overall, with the low-elongation group showing 0.10 ± 0.05 mm/year and the high-elongation group showing 0.27 ± 0.06 mm/year. Children with lower initial spherical values and older individuals demonstrated less axial elongation.

CONCLUSION

Age and initial equivalent spherical value are critical factors influencing axial length changes in children aged 9-17 years who use Ortho-K lenses. Understanding these factors can enhance the effectiveness of Ortho-K treatment in managing myopia progression. Further studies are needed to optimize lens design and treatment protocols for personalized myopia control.