Monthly Replacement Orthokeratology for Myopia Control in Young Children

Accrued Effect of Orthokeratology for Myopia Control in Children and the Effectiveness of Myopia Control Using an Innovative Orthokeratology Modality. Experiment 2. Effect in New Ortho-k Wearers

The two-year prospective study aims at investigating frequently replacement effect on myopia control in young children, and the use of weekly protein removal system in monthly replacement modality orthokeratology lenses on surface deposit.

In this two-year prospective study, low myopic children, aged 6-8 years, who have no prior experience in contact lens wear and myopia control treatment will be recruited. They will be prescribed with monthly replacement orthokeratology lenses for a period of one year. Axial elongation and ocular conditions during the study will be determined. Subjects will be randomly assigned to normal cleaning and intensive cleaning groups. Subjects in normal cleaning group will be provided with complimentary contact lenses solutions for daily cleaning and disinfection. In addition to the daily procedures for lens case, subjects in the intensive cleaning group will be required to perform weekly protein removal.

Inclusion Criteria:

• Aged 6-10 years
• Normal ocular and general condition and not on medication which may contraindicate ortho-k lens wear
• Refractive sphere between -0.75 to -4.00 D, refractive cylinder ≤ -1.50 D and anisometropia ≤ -1.00 D
• Best correctable vision better than 0.08 logMAR in the worse eye
• Normal binocular function and accommodative status
• No prior experience in contact lens wear and myopia control treatment

Exclusion Criteria:

• Strabismus at distance or near
• Contraindication for ortho-k lens wear
• Prior history of ocular surgery, trauma, or chronic ocular disease
• Systemic or ocular conditions that may interfere refractive development
• Systemic or ocular conditions that may interfere tear quality and contact lens wear
• Poor response to the use of study lenses
• Poor compliance to test procedures
• Poor compliance to the use of ortho-k lenses (e.g. use of solution, use of lenses)
• Poor compliance to follow-up schedule