Younger age, female sex, lower baseline myopia, a steeper flatest keratometry meridian, and less time spent performing near work tasks are associated with better patient outcomes in children using orthokeratology (orthoK) lenses for myopia control, according to research published in Ophthalmic and Physiologial Optics.
Researchers conducted a 2-year prospective study to examine the effect of various ocular characteristics and environmental factors on myopia control for patients wearing orthoK lenses (N=24, mean age 9.73±1.55 years, 54.2% boys). They recorded age, sex, and height for all participants and performed ocular measurements including choroidal thickness and axial length. The team also considered time spent performing near work, time spent sleeping, and time spent outdoors. Study duration was 2 years and the investigators performed follow-up visits every 3 months throughout the study.
The team determined that female sex, younger age, lower baseline myopia, a steeper flattest keratometry reading, and performing near work for less than 5 hours per day were associated with better myopia control while using orthoK. They noted significant changes in axial length from 9 months until the 2 year conclusion of the study among the cohort (0.44±0.30 mm OD and 0.37±0.26 mm OS, both P <.001).
The investigators did not establish any significant associations between myopia control and intraocular pressure (IOP), choroidal thickness, central corneal thickness, average outdoor time per day, or sleep time (P ≥.06 for all).
Researchers assert that while it is important to monitor conventional ocular measurements when treating patients with orthoK, clinicians must not overlook patient lifestyle. “While investigating factors related to orthokeratology lens wear for myopia control, as well as changes in the individual wearer, environmental factors must also be considered,” according to the report.
Study limitations include a small sample size and single center design.
Chen X, Xiong Y, Liu F, Wang J, Yang B, Liu L. Factors determining the myopia control effect of an orthokeratology lens: a two-year multi-level model. Ophthalmic Physiol Opt. Published online May 2, 2022. doi:10.1111/opo.12990