Orthokeratology and 0.01% Atropine Sequential Treatment for Myopia Control

Myopia Control Effect of Orthokeratology and 0.01% Atropine Sequential Treatment in Children and Adolescents: A Multicenter Randomized Controlled Trial

The purpose of this multicenter randomized clinical trial is to evaluate the myopia control effect of orthokeratology and 0.01% atropine sequential treatment in children and adolescents, as compared to continuous treatment with orthokeratology.

Myopia constitutes a major threat to vision health globally for its increasing prevalence and irriversible blinding complications. It is crucial to effectively intervene subjects with progressive myopia to reduce risks of myopic pathologies in later life.

Orthokeratology (ortho-k) is the first-line intervention for myopia control, with an efficacy of slowing axial elongation by 43-63%. However, the efficacy decreases over time. Sequential treatment strategy, which switches myopia control interventions at some intervals, has a potential to increase myopia control efficacy regarding the whole treatment period, compared to applying one intervention throughout. However, there lacks evidence supporting the benefit of this treatment strategy.

The purpose of this study is to evaluate the effectiveness of orthokeratology and 0.01% atropine sequential treatment on myopia control in children and adolescents, as compared to continuous treatment with orthokeratology, using a multicenter randomized controlled trial design. Subjects will be randomly assigned into either ortho-k and 0.01% atropine sequential treatment group or ortho-k continuous treatment group. Their axial length will be monitored over two years. Changes in axial length in the two groups will be compared.

Inclusion Criteria:

1. Aged 8-15 years old.
2. Spherical equivalent refractions (SERs) -0.50 to -6.00 Dioptres (D) and astigmatism less than -1.5 D in both eyes, anisometropia less than 1.5 D.
3. Best corrected visual acuity (BCVA) equal to or better than 20/25 in both eyes.
4. Bilateral intra-ocular pressure < 21mmHg.
5. Normal binocular and stereoscopic visual function.
6. Participants and their guardians' understanding and acceptance of random allocation of grouping.

Exclusion Criteria:

1. Manifest strabismus, except for intermittent tropia.
2. Ocular or systemic diseases which may affect vision or refractive error.
3. Previous use of myopia control without washout, including atropine, myopia control spectacles, myopia control contact lenses.
4. Other contraindications.