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Novel quantitative analysis of relative peripheral refraction changes in orthokeratology and their relationship with
1Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China.
Insights
Orthokeratology (ortho-k) therapy shifts peripheral refraction towards myopia, particularly in the inferior retina. Greater myopic shifts in specific peripheral zones correlate with better control of axial length growth in children.
Area of Science:
- Ophthalmology and Optometry
- Myopia Control
- Refractive Error
Background:
- Myopia is a growing public health concern, especially in children.
- Orthokeratology (ortho-k) is a non-surgical method to correct myopia.
- Understanding peripheral refraction changes is crucial for myopia management strategies.
Purpose of the Study:
- To analyze changes in relative peripheral refraction (RPR) after one year of ortho-k.
- To determine the association between RPR alterations and axial length (AL) growth.
- To identify specific retinal regions where RPR changes influence myopia progression.
Main Methods:
- Prospective cohort study of 60 myopic children (aged 8-15 years).
- Measurement of RPR and AL at baseline and 12 months post-ortho-k.
- Multispectral refraction topography (MRT) used for RPR assessment across fundus fields and quadrants; linear regression for association analysis.
Main Results:
- Ortho-k induced significant myopic shifts in all measured peripheral retinal subregions (p < 0.05).
- Hyperopic peripheral refractive errors became myopic, especially within the 50° region and in superior, inferior, and nasal quadrants.
- Baseline AL and RPR changes in the 30-40° region and inferior retina were independently linked to AL elongation (p < 0.05).
Conclusions:
- Ortho-k treatment effectively induces myopic shifts in peripheral refraction.
- The magnitude of induced myopic shift in the 30-40° and inferior retinal zones predicts the efficacy of ortho-k in controlling axial elongation.
Purpose:
To investigate changes in relative peripheral refraction (RPR) and their associations with axial length (AL) growth after one year of orthokeratology (ortho-k) therapy.
Methods:
This prospective cohort study included 60 myopic children aged 8-15 years. RPR and AL were measured at baseline and 12 months after ortho-k therapy. Total RPR was measured via multispectral refraction topography (MRT) in the 53° fundus field of view, and then was divided into specific annuli (0-10°, 10-20°, 20-30°, 30-40°, 40-50° and 50-53°) and quadrants (superior, inferior, temporal and nasal). Linear regression analyses quantified associations between RPR changes and AL elongation.
Results:
Ultimately, 80.0 % of the participants were analysed. The total RPR was 0.64 ± 0.26 D at baseline and -0.35 ± 0.64 D at 12 months. Ortho-k therapy induced myopic shifts in all subregions (all p < 0.05). Additionally, hyperopic RPRs within the 50° region and in the superior, inferior and nasal parts of the retina became myopic. These myopes had an asymmetric RPR in the vertical retina both before and after ortho-k treatment but a symmetric RPR in the horizontal retina, which changed after treatment. Multivariate linear regression analyses revealed that the baseline AL and RPR changes in the 30-40° region and in the inferior retina were independently associated with AL elongation during one-year of ortho-k lens wear (all p < 0.05).
Conclusions:
The more myopic shifts of RPR induced by ortho-k treatment in the 30° to 40° region and in the inferior retina, the more effective control of axial elongation.
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