The Effect of Treatment Zone Decentration on Myopic Progression during Or-thokeratology

ABSTRACT

Purpose: To evaluate the relationship between magnitude of orthokeratology (OrthoK) treatment zone decentration and 2-year axial length (AL) elongation in myopic children.

Methods: One-hundred and one Chinese children who wore OrthoK contact lenses for 2 years. The magnitude and direction of the OrthoK treatment zone center from the entrance pupil center were recorded after 3 and 24 months of lens wear along with AL measurement. Stepwise multiple linear regression analysis was performed to assess which factors significantly affected an increase in AL.

Results: After 3 and 24 months of OrthoK treatment, the mean (± standard deviation [SD]) magnitude of the OrthoK treatment zone decentration was 0.64 ± 0.38 mm and 0.68 ± 0.32 mm, respectively. There were no significant differences between the two time points (P > .05). After 2 years of OrthoK contact lenses wear, the mean (± SD) AL growth was 0.36 ± 0.34 mm. The axial elongation was slightly correlated with baseline age of subjects (r = −0.073, P < .001), baseline spherical equivalent refractive error (r = −0.088, P < .001) and magnitude decentration of treatment zone (r = −0.190, P = .027).

Conclusions: The decentration of OrthoK treatment zone stabilizes after 3 months of lens wear and slightly decreases AL growth.

KEYWORDS:

• Orthokeratology
• myopic children
• zone decentration
• axial growth

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Foundation of Wenzhou City Science & Technology Bureau [Y20170194, Y20180174]; Zhejiang Provincial High-level Talents Program [2017-102]; Science and Technology Planning Project of Zhejiang Province [LGF19H120002].