Baseline Relative Peripheral Refraction in Myopia Control

The Influence of Baseline Relative Peripheral Refraction in Myopia Control Using Myopic Defocus

Myopia has become a world concern and its prevalence has increased in recent decades. Myopic defocus has been applied for slowing down the axial elongation and myopia progression, which is mainly based on the theory of simultaneous competing defocus and peripheral optics. Defocus Incorporated Multiple Segments (DIMS) spectacle lenses impose myopic defocus in the central or peripheral retina, with myopia progression being retarded by 50% to 60%. However, the optimal amount of myopic defocus has not yet been determined. Relative peripheral refraction (RPR) is used to indicate the difference between peripheral refraction and central refraction. Previous studies showed that retinal shape determined RPR, and baseline RPR may influence the myopia control efficacy using DIMS lenses on myopic children. It is still unclear if any other unknown factor influenced the final myopia control outcome in these young children with myopic RPR at baseline. Unlike our previous study8 that bias on hyperopic RPR children (myopic RPR, n = 27; hyperopic RPR, n = 52), this study is a case-control study with the same sample size for each RPR group. We will also include younger children who are more prone to have myopic RPR and develop high myopia. The results should provide new insight into the myopia control strategy in early-onset myopic children.

In the current study, we will investigate the influence of baseline RPR in myopia retardation using DIMS lenses among young myopic children.

This will ba a 1-year prospective clinical trial. Through G*Power (version 3.1.9.6) calculation, 80 healthy myopic subjects (40 myopic RPR vs 40 hyperopic RPR) aged 5-9 years should be needed. After screened by inclusion criteria, eligible participants will be assigned to wear DIMS lenses for 1 year (12 months, 8 hour per day, 7 days per week). This study includes 5 visits: Visit 1: baseline, Visit 2: lens dispensing, Visit 3: 2-week follow-up, Visit 4: 6-month follow-up, and Visit 5: 12-month follow-up. All eye examinations will be carried out in the Optometry Research Centre (A137), the School of Optometry, the Hong Kong Polytechnic University. The main data collection, including refractive error, axial length, related ocular parameters will be measured at baseline, 6-month and 1-year visits. At the lens dispensing and 2-week follow-up visits, vision acuity testing and computer scanning of posterior eyes will be measured. New DIMS lens will be replaced and upgraded if the equivalent sphere of refraction (SER) is changed or visual acuity change.

The following data will be statistically analyzed. The primary outcome data include the difference in change in SER with cycloplegia between the myopic and hyperopic RPR from the baseline over 12 months of treatment. Secondary outcomes data include the changes in axial length, peripheral refraction, relative peripheral refraction, the amplitude of accommodation, lag of accommodation, corneal curvature, phoria and stereoacuity.

Study Overview

• Status: Recruiting
• Conditions: Myopia
• Intervention / Treatment: Device: DIMS lenses

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Tsz Wing Leung, PhD; Phone Number: 27664268; Email: jeffrey.TW.leung@polyu.edu.hk

Study Locations

• Hong Kong
  • Hong Kong, Hong Kong, nol
    • Recruiting
    • Optometry Research Clinic
    • Contact: Tsz Wing Leung, PhD; Phone Number: 27664268; Email: jeffrey.TW.leung@polyu.edu.hk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age at enrolment: 6-9 years
• Spherical equivalent refraction (SER): -0.75 to -5.00 Diopters (D)
• Astigmatism: -1.50 D or less
• Anisometropia: 1.50 D or less
• Spectacle best-corrected monocular visual acuity (VA): 0.00 logMAR or better

Exclusion Criteria:

• Ocular and systemic abnormalities might affect visual functions or refractive development
• Prior use of any drugs or optical devices of myopia control treatment.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Myopic RPR group; Patients with myopic relative peripheral refraction	Device: DIMS lenses; Defocus incorporated multiple segments lenses, which use induce peripheral myopic defocus to control for myopia development in children
Active Comparator: Hyperopic RPR group; Patients with hyperopic relative peripheral refraction	Device: DIMS lenses; Defocus incorporated multiple segments lenses, which use induce peripheral myopic defocus to control for myopia development in children

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cycloplegic refractive error	Refractive error measured after instillation of cycloplegia	Baseline; 2 weeks, 6 months and 12 months post-treatment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Axial length	Length of the eye	Baseline; 2 weeks, 6 months and 12 months post-treatment
Peripheral refraction	Refractive errors at peripheral fields	Baseline; 2 weeks, 6 months and 12 months post-treatment
Amplitude and lag of accommodation	Ability of the eyes to accommodate	Baseline; 2 weeks, 6 months and 12 months post-treatment
Corneal curvature	Power of the cornea	Baseline; 2 weeks, 6 months and 12 months post-treatment
Phoria and stereoacuity	Coordination of the two eyes	Baseline; 2 weeks, 6 months and 12 months post-treatment

Collaborators and Investigators

• Sponsor: The Hong Kong Polytechnic University
• Collaborators: HOYA Lamphun Ltd; Centre for Eye and Vision Research

Study record dates

Study Major Dates

• Study Start (Estimated): December 1, 2023
• Primary Completion (Estimated): April 3, 2025
• Study Completion (Estimated): April 3, 2025

Study Registration Dates

• First Submitted: November 30, 2023
• First Submitted That Met QC Criteria: November 30, 2023
• First Posted (Actual): December 7, 2023

Study Record Updates

• Last Update Posted (Actual): December 7, 2023
• Last Update Submitted That Met QC Criteria: November 30, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Eye Diseases; Refractive Errors; Myopia
• Other Study ID Numbers: HSEARS20221229003-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No