September 16, 2024
By Dwight Akerman, OD, MBA, FAAO, FBCLA, FIACLE
Photo Credit: Getty Images
The paper “A New Look at the Myopia Control Efficacy of Orthokeratology” by Santodomingo-Rubido, Cheung, and Villa-Collar, published in Contact Lens and Anterior Eye in 2024, presents research on the efficacy of orthokeratology contact lens wear in slowing the axial elongation in myopic children. The researchers pooled data from three prospective studies to evaluate the use of OrthoK for slowing myopia progression in children, comparing it to a parallel control group of distance, single-vision spectacle lens wearers over a two-year period.
The analysis included data from 125 OrthoK and 118 control subjects. Of these, 101 OrthoK subjects (81%) and 88 control subjects (75%) completed the two-year follow-up period. The results revealed statistically significant differences in the change in axial length from baseline over time, between groups, and for the time group interaction (all p < 0.001). This indicates that the rate of increase in axial length over time was significantly lower in the OrthoK group compared to the control group. The study found that the lower axial elongation of the OrthoK group was statistically significant at all time points, with significant differences present between each of the different pairs of time points.
The change in axial length at the two-year visit in comparison to baseline for the OrthoK and control groups were 0.41 ± 0.25 and 0.65 ± 0.30 mm, respectively, providing a treatment effect following two years of lens wear of 0.24 mm (95% confidence intervals: 0.15 to 0.34 mm). The two-year effect size of 0.24mm is similar to previous studies that have reported that increases in axial length of approximately 0.1mm to 0.2mm annually are typically observed in mild hyperopic to emmetropic Caucasian children of similar age as those from this study, who remain emmetropic. During the first year of treatment, 62.5 % of the two-year treatment effect was obtained, indicating that there appears to be an initial burst in efficacy during the first year of treatment, with efficacy typically decreasing subsequently over time, the authors noted.
The study also found that 40% and 25% of the OrthoK subjects experienced remarkably low and high levels of myopia progression, respectively (two-year axial elongation: ≤0.30 mm and >0.59 mm, respectively).
In conclusion, OrthoK lens wear was found to provide a clinically and statistically significant reduction in the axial elongation of the eye of 0.24 mm in comparison to the control group of spectacles lens wearers over a two-year period, with 62.5 % of the treatment effect being obtained during the first year of treatment. Around 40 % of OrthoK lens-wearing subjects showed very low levels of myopia progression, with 8% of these showing no axial elongation or a shrinkage in axial length. In contrast, one third of OrthoK lens-wearing subjects showed limited benefit from OrthoK lens wear for slowing myopia progression and a further quarter of OrthoK lens-wearing subjects did not show any benefit from lens wear for slowing axial elongation.
Abstract
A New Look at the Myopia Control Efficacy of Orthokeratology
Jacinto Santodomingo-Rubido, Sin-Wan Cheung, César Villa-Collar, ROMIO/MCOS/TO-SEE Groups
Purpose: To evaluate the efficacy of orthokeratology contact lens wear in slowing the axial elongation of the eye in myopic children.
Methods: Data from three prospective studies, which evaluated the use of orthokeratology for slowing myopia progression in children in comparison to a parallel control group of distance, single-vision spectacle lens wearers over a 2-year period, were pooled together for analysis.
Results: Collectively, data from 125 orthokeratology and 118 control subjects were analyzed in this study. Of these, 101 (81 %) and 88 (75 %) orthokeratology and control subjects completed the 2-year follow-up period, respectively. Statistically significant differences in the change in axial length from baseline were found over time, between groups and for the time*group interaction (all p < 0.001), indicating that the rate of increase in axial length over time was significantly lower in the orthokeratology versus the control group. The lower axial elongation of the orthokeratology versus the control group was statistically significant at all time points (all p < 0.001), with significant differences being also present between each of the different pairs of time points (all p < 0.001). The interactions of the group with age, gender, mean spherical refractive error, and ethnicity at baseline were not significant (p > 0.05). The change in axial length at the 2-year visit in comparison to baseline for the orthokeratology and control groups were 0.41 ± 0.25 and 0.65 ± 0.30 mm, respectively, thus providing a treatment effect following 2-years of lens wear of 0.24 mm (95 % confidence intervals: 0.15 to 0.34 mm). About 40 % and 25 % of the orthokeratology subjects experienced remarkably low and high levels of myopia progression, respectively (2-years axial elongation: ≤0.30 mm and >0.59 mm, respectively).
Conclusions: Orthokeratology lens wear slows the axial elongation of the eye in comparison to spectacle lens wear in myopic children. The use of these lenses for slowing myopia progression appears to be very effective and not effective at all in 40% and 25% of orthokeratology lens wearers, respectively.
Santodomingo-Rubido J, Cheung SW, Villa-Collar C, et al. (2024) A new look at the myopia control efficacy of orthokeratology. Cont Lens Ant Eye. June 21, 2024. [Epub ahead of print.]
DOI: https://doi.org/10.1016/j.clae.2024.102251
Some products covered in Review of Myopia Management are prescribed off-label in the United States because they are not FDA-approved for slowing the progression of myopia in children.
