Clinical trial NCT04295707: Monthly Replacement Orthokeratology for Myopia Control in Existing Lens Wearers
Official title: 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
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Myopic Progression
Keywords: Myopia progression
Orthokeratology
Replacement modality
Surface deposits
Lead sponsor: The Hong Kong Polytechnic University
Sponsor class: OTHER
Collaborators: name: Menicon Co., Ltd.
First posted: 2020-03-04
Enrollment: 80
Sex: ALL
Minimum age (years): 8
Maximum age (years): 15
Standard ages: CHILD
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
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.
Primary purpose: TREATMENT

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.

Eligibility criteria: 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

Primary outcomes:
measure: Axial elongation in 2 years
timeFrame: 2 years
measure: Back Surface Lens Deposits
timeFrame: Every month up to 12 months
Secondary outcomes:
measure: Number of participants with serious adverse effects in 2 years
timeFrame: 2 years
Other outcomes:
Locations:
city: Kowloon
country: Hong Kong
facility: School of Optometry, The Hong Kong Polytechnic University
Study officials:
affiliation: The Hong Kong Polytechnic University
name: Pauline Cho, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Lee YC, Wang JH, Chiu CJ. Effect of Orthokeratology on myopia progression: twelve-year results of a retrospective cohort study. BMC Ophthalmol. 2017 Dec 8;17(1):243. doi: 10.1186/s12886-017-0639-4.
citation: Stapleton F, Carnt N. Contact lens-related microbial keratitis: how have epidemiology and genetics helped us with pathogenesis and prophylaxis. Eye (Lond). 2012 Feb;26(2):185-93. doi: 10.1038/eye.2011.288. Epub 2011 Dec 2.
citation: Cho P, Cheung SW. Retardation of myopia in Orthokeratology (ROMIO) study: a 2-year randomized clinical trial. Invest Ophthalmol Vis Sci. 2012 Oct 11;53(11):7077-85. doi: 10.1167/iovs.12-10565.
citation: Hiraoka T, Kakita T, Okamoto F, Takahashi H, Oshika T. Long-term effect of overnight orthokeratology on axial length elongation in childhood myopia: a 5-year follow-up study. Invest Ophthalmol Vis Sci. 2012 Jun 22;53(7):3913-9. doi: 10.1167/iovs.11-8453.
citation: Cheung SW, Boost MV, Cho P. Pre-treatment observation of axial elongation for evidence-based selection of children in Hong Kong for myopia control. Cont Lens Anterior Eye. 2019 Aug;42(4):392-398. doi: 10.1016/j.clae.2018.10.006. Epub 2018 Oct 24.