Myopic Progression
Conditions
Keywords
Myopia progression, Orthokeratology, Replacement modality, Surface deposits
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.
Interventions
DEVICEorthokeratology
Nightly wear of orthokeratology lenses to correct vision in the daytime
DEVICEMenicon Progent A+B
Menicon Progent A+B is a commercially available protein remover for rigid lenses. It has received FDA clearance and been launched in Hong Kong for over a decade. The product contains two separate sterile solutions, one with sodium hypochlorite and the other with potassium bromide. By mixing the two solutions in a special vial, it can clean and remove protein deposits on the lenses. Parents of subjects assigned to use weekly protein remover will be required to soak the cleansed lenses in the solution mixture for not more than 30 mins every week. All lenses must be rinsed thoroughly with saline and cleansed with daily cleaner again before daily disinfection.
Sponsors
Menicon Co., Ltd.
The Hong Kong Polytechnic University
Study design
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.
Intervention model description
All subjects will be randomly assigned to use monthly or yearly replacement orthokeratology for a period of 24 months. Subjects on monthly replacement modality 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. Intensive cleaning is indicated for yearly replacement modality, thus, no randomization of care procedures in this group.
Eligibility
Sex/Gender
ALL
Age
8 Years to 15 Years
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Axial elongation in 2 years | 2 years | Cycloplegic examination of the eyeball length using IOLMaster every 6 monthly |
| Back Surface Lens Deposits | 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
| Measure | Time frame | Description |
|---|---|---|
| Number of participants with serious adverse effects in 2 years | 2 years | Number of subjects with serious adverse effects of the cornea, the palpebral, bulbar and tarsal conjunctiva in 2 years |
Countries
Hong Kong
Outcome results
None listed