Accrued Effect of Orthokeratology for Myopia Control in Children and the Effectiveness of Myopia Control Using an Innovative Orthokeratology Modality. Experiment 1. Effect in Existing Ortho-k Wearers
Trial Snapshot
- Phase
- Not Applicable
- Enrollment
- 80
- Locations
- 1
- Primary Endpoint
- Axial elongation in 2 years
Study Overview
Brief Summary
The two-year prospective study aims at investigating the benefits of frequent replacement (monthly) orthokeratology lenses in myopia control in terms of effectiveness in control and prevention of ocular complications. The secondary objective will be investigating the use of weekly protein removal system in monthly replacement modality orthokeratology lenses on surface deposit.
Detailed Description
This is a two-year randomized trial. Existing orthokeratology lens wearers (aged 8-13 years), who have completed a 2-year myopia control using orthokeratology, will be recruited and monitored for another two years. Eligible subjects will be randomly assigned to monthly or yearly replacement modality. Axial elongation and ocular conditions will be compared between the monthly and yearly replacement groups.
Subjects on monthly replacement lenses 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. All subjects on yearly replacement lenses will be required to performed intensive cleaning such that they will follow normal daily cleaning and disinfection as well as weekly protein removal.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Treatment
- Masking
- Single (Outcomes Assessor)
Masking Description
The outcome assessor was responsible for measuring the axial length and was unaware of the replacement modality of intervention used by the subjects. Another independent examiner will be responsible for grading surface coating from the images taken without disclosure of the information on the cleaning procedures.
Eligibility Criteria
- Ages
- 8 Years to 15 Years (Child)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Aged 8-15 years
- •Have completed a two-year myopia control study using ortho-k
- •Normal ocular and general condition and not on medication which may contraindicate ortho-k lens wear
- •Pre-ortho-k refractive sphere between -0.75 to -4.00 DS, refractive cylinder ≤ -1.50 DC and anisometropia ≤ -1.00 D
- •Best correctable vision better than 0.08 logMAR in the worse eye
- •Normal binocular function and accommodative status
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
Arms & Interventions
Monthly replacement orthokeratology without protein removal
Subjects will be required to perform daily cleaning for the monthly replacement orthokeratology lenses
Intervention: orthokeratology (Device)
Monthly replacement lenses with weekly protein removal
Subjects will be required to perform both daily cleaning and weekly protein removal for the monthly replacement orthokeratology lenses
Intervention: orthokeratology (Device)
Monthly replacement lenses with weekly protein removal
Subjects will be required to perform both daily cleaning and weekly protein removal for the monthly replacement orthokeratology lenses
Intervention: Menicon Progent A+B (Device)
Yearly replacement lenses with weekly protein removal
Subjects will be prescribed with orthokeratology lenses which will be replaced at least every 12 months during the study period. They will be required to perform both daily cleaning and weekly protein removal for their lenses.
Intervention: orthokeratology (Device)
Yearly replacement lenses with weekly protein removal
Subjects will be prescribed with orthokeratology lenses which will be replaced at least every 12 months during the study period. They will be required to perform both daily cleaning and weekly protein removal for their lenses.
Intervention: Menicon Progent A+B (Device)
Outcomes
Primary Outcomes
Axial elongation in 2 years
Time Frame: 2 years
Cycloplegic examination of the eyeball length using IOLMaster every 6 monthly
Back Surface Lens Deposits
Time Frame: Every month up to 12 months
Surface deposits will be graded using a 4-point scale: 0=no deposit; 1=mild; 2=moderate; 3=severe
Secondary Outcomes
- Number of participants with serious adverse effects in 2 years(2 years)
Investigators
Pauline Cho
Professor
The Hong Kong Polytechnic University