Peripheral Optics in Myopia and Orthokeratology

Inclusion Criteria:

• Myopia (refractive sphere): > 0.50D and ≤ 6.00D
• Astigmatism: with-the-rule astigmatism (axes 180 +/- 30) ≤ 1.50D; astigmatism of other axes ≤ 0.50D
• Spherical equivalent (SE): > 0.50D and ≤ 6.75D (myopia)
• Best corrected monocular visual acuity: equal to or better than 6/7.5 in Snellen scale
• Willingness to wear contact lenses or spectacles on a daily basis
• Availability for follow-up for at least 2 years

Exclusion Criteria:

• Strabismus at distance or near
• Contraindication for contact lens wear and orthokeratology (e.g. limbus to limbus corneal cylinder and dislocated corneal apex)
• Prior experience with the use of rigid lenses (including orthokeratology)
• Prior experience with myopic control treatment (e.g. refractive therapy or progressive spectacles)
• Systemic or ocular conditions which may affect contact lens wear (e.g. allergy and medication)
• Systemic or ocular conditions which may affect refractive development (e.g. Down syndrome, ptosis)