Orthokeratology (OK) has been demonstrated to be an effective intervention for slowing axial elongation in children with myopia. The proposed mechanism of action is the induction of peripheral myopic defocus, which reduces relative peripheral hyperopia on the retina.

This study aims to evaluate changes in relative peripheral retinal refraction before and after OK lens wear using wide-field multispectral retinal refractive topography. The study will also investigate the relationship between these retinal refractive changes and the effectiveness of OK in controlling axial elongation.

Inclusion Criteria:

• 8 to 15 years old
• myopia of -4.00D or lower,
• regular astigmatism ≤1.50D and non-regular astigmatism ≤1.00D
• intraocular pressure ≤21mmHg
• understand the purpose of the study and have good hygiene and regular follow-up

Exclusion Criteria:

• unilateral
• immunocompromised subjects with systemic diseases (such as acute or chronic sinusitis, diabetes mellitus, Down syndrome, rheumatoid arthritis, psychiatric patients, etc.)
• complicated with other eye diseases that affect OK lens wearing, such as dacryocystitis, blepharitis and other inflammation, glaucoma, etc.
• BCVA less than 1.0
• children with corneal curvature less than 40.00D or higher than 46.00D.

Children aged 8 to 15 years with myopia who are eligible for and fitted with orthokeratology lenses. Participants must demonstrate the ability to maintain adequate compliance with lens wear and follow-up requirements.