Monthly Replacement Orthokeratology for Myopia Control in Existing Lens Wearers

Not Applicable

• Conditions: Myopic Progression

• Registration Number: NCT04295707
• Lead Sponsor: The Hong Kong Polytechnic University

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 Timeline

• Study First Submitted: 2020-02-29
• Study First Submitted QC: 2020-03-03
• Study First Posted: 2020-03-04
• Study Start: 2020-03-11
• Status Verified: 2022-07
• Last Update Submitted: 2022-07-18
• Last Update Posted: 2022-07-19
• Primary Completion: 2023-06
• Study Completion: 2023-08

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 80

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
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 Outcome Measures

Name	Time	Method
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

Trial Locations

Locations (1)

School of Optometry, The Hong Kong Polytechnic University; 🇭🇰 Kowloon, Hong Kong