1. Study Design The study will employ a randomized, controlled, investigator-masked paired-eye comparison design to evaluate the effects of two myopia-control contact lenses-MiSight 1 Day and Abiliti 1-Day-in New Zealand Chinese children. The study duration will be 6 months, with assessments conducted at baseline, 2 weeks, 3 months, and 6 months. The clinical research will be conducted at the Auckland Myopia Clinic (New Zealand) and will follow a standard clinical routine for children with early myopia, the only difference being the randomizing of the MiSight and Abiliti contact lenses between the two eyes of the participants.
2. Participants 2.1 Recruitment and Eligibility Criteria • Participants: 53-66 New Zealand Chinese children aged 7-11 years.
* Inclusion criteria:
o Spherical refractive error between -1.00D and -4.50D
o Astigmatism of ≤1.00D
o No history of orthokeratology or atropine use
o No ocular diseases or surgical history
* Recruitment will be through social media, patient referrals, and school outreach.
2.2 Sample Size A similar study, of soft contact lenses with novel ring focus for controlling myopia progression, based their sample size on treatment efficacy of \>0.08 mm (standard deviation \[SD\]: 0.10) in axial elongation from baseline and \>0.20 D (SD: 0.32) in change of spherical equivalent cycloplegic autorefraction (SECAR) from baseline at 26 weeks. Controlling the 2-sided type I error rate at the 0.05 level, the researchers found that sample size of 40 subjects per group would yield \>80% power for detecting treatment efficacy.
To estimate the sample size for the present study, a priori power analysis was performed using the program G∗Power (version 3.1.9.7). For a 95% confidence interval (Z = 1.96) and a study power of 80%, and controlling the 2-sided type I error rate at the 0.05 level, the estimated sample size is 53 pairs of eyes (53 subjects), as each participant contributes both eyes to the study. Providing for a 20% dropout rate, the recruitment target becomes 66 participants.
3. Interventions
Each participant will wear:
• MiSight 1 Day dual-focus lens in one eye (2.00D defocus)
• Abiliti 1-Day lens in the contralateral eye (7.00D defocus)
4. Data Collection Methods 4.1 Baseline and Follow-up Assessments
• Cycloplegic refraction (CycloRx) and retinoscopy (Ret) will be conducted.
• Axial length will be measured using MYAH optical biometry.
• Ocular surface assessments:
o Children Dry Eye Questionnaire (CDEQ) responses
o Non-invasive Tear break-up time (NIBUT) using MYAH's dry eye function
o Ocular Protection Index (OPI) calculation using MYAH
* Corneal staining assessment via MYAH corneal staining and slit lamp fluorescein
* Lissamine green conjunctiva staining (graded and recorded) 4.2 Timepoints for Data Collection
• Baseline (0 months): Cycloplegic refraction, axial length, CDEQ, NIBUT, OPI, corneal staining.
* 2 weeks: Axial length, ocular surface assessments, dry eye symptoms.
* 3 months: Axial length, ocular surface assessments, dry eye symptoms.
* 6 months: Final assessments of axial length, ocular surface health, and dry eye symptoms.
5. Outcome Measures
1\. Myopia-control efficacy: Comparison of axial length elongation between the two contact lenses.
2\. Ocular surface health:
o CDEQ responses
* NIBUT measurements
* OPI calculation
* Corneal staining severity Should one lens slow the development of myopia more than the other, the lenses will be reversed at the end of the study.
6\. Parent Perception Questionnaire
A structured questionnaire will be administered at baseline and at 6 months to assess parents' expectations and perceptions of the contact lenses as a myopia treatment. Topics covered include:
* Baseline Questionnaire: Motivations, barriers, facilitators, and expectations for contact lens treatment.
* Follow-up Questionnaire: Changes in attitudes, satisfaction with treatment compared to initial expectations, and future adherence.
7\. Ethical Considerations The study will comply with optometric ethical standards. Participants and parents will provide informed consent. Data confidentiality will be maintained, and the study will be subject to institutional ethics review.
8\. Study Personnel The study will be investigator-masked and conducted by two paediatric optometrists,who each have extensive experience in myopia management. Both have conducted over 800 paediatric myopia exams.
9\. Statistical Analysis Data will be analysed using SPSS software. Axial length changes will be compared between paired eyes using paired t-tests. Dry eye symptoms and corneal staining scores will be analysed using a repeated measures ANOVA.
