Optical Biometry Changes Throughout Childhood and Adolescence in Patients Wearing Ortho-K Lenses

Abstract

Background

Orthokeratology has been shown to suppress progressive myopia in some children. We examine the changes in optical biometry parameters in orthokeratology (Ortho-K) patients, in a retrospective longitudinal study at a tertiary eye care center in Ann Arbor, MI, USA.

Methods

Optical biometry measurements obtained with the Lenstar LS 900 (Haag-Streit USA Inc, EyeSuite software version i9.1.0.0) were aggregated from 170 patients who had undergone Ortho-K for myopia correction between 5 and 20 years of age. Pre-intervention biometry measurements were compared with follow-up measurements done 6–18 months after initiation of Ortho-K. Linear mixed models were used to quantify associations in biometry changes with age of intervention allowing for correlation between measurements on two eyes of the same patient.

Results

A total of 91 patients were included in the study. Axial length increased through the age of 15.7 ± 0.84 years for Ortho-K patients at our center. The growth curve in our Ortho-K population was comparable to previously published normal growth curves in Wuhan and Germany populations. Corneal thickness and keratometry decreased at a stable rate regardless of age of intervention (−7.9 µm, 95% CI [−10.2, −5.7], p < 0.001).

Conclusion

In our population, Ortho-K did not appear to affect the overall trajectory of axial length progression when compared to normal growth curves, despite showing a previously described reduction in corneal thickness. As Ortho-K has been shown to have varying effects that differ from individual to individual, it continues to be important to reassess its effects on new populations to better understand its ideal uses.

Keywords:

• orthokeratology
• biometry
• pediatrics
• axial length
• corneal thickness

Abbreviations

Ortho-K, Orthokeratology; AL, Axial length; LT, lens thickness; CCT, central corneal thickness; K1, flat keratometry; K2, steep keratometry.

Data Sharing Statement

The datasets generated and/or analyzed during the current study are not publicly available to protect patient privacy but are available from the corresponding author on reasonable request.

Ethics Approval and Consent to Participate

Institutional review board approval (University of Michigan’s Human Research Protection Program (HRPP)) was obtained for the study from the Institutional review board of University of Michigan. Additionally, Institutional review board of University of Michigan has waived informed consent for the study because of its retrospective nature and the anonymized data utilized in this study. The study was carried out in accordance with the tenets of the Declaration of Helsinki.

Author Contributions

All authors made substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; took part in drafting the article or revising it critically for important intellectual content; agreed to submit to the current journal; gave final approval of the version to be published; and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.

Additional information

Funding

Supported by GME Innovations Fund, The Doctors Company Foundation, and NIH K12EY022299.