Myopia Control Using Bright Light Therapy, Myopic Defocus and Atropine

Study Overview
=================
Brief Summary
-----------------
The purpose of the study is to investigate the effect of bright light therapy, myopic defocus, atropine and the combination in myopia control in schoolchildren.

Detailed Description
-----------------
The present study is a multi-arm randomised clinical trial with a 24-month duration. Subjects will be healthy Hong Kong Chinese schoolchildren with low to moderate myopia. The aims are to determine the clinical effectiveness of bright light therapy on inhibiting myopia progression in schoolchildren, and to determine whether combination therapy using bright light therapy (BLT) and myopic defocus is more effective than monotherapy. Study population Seven hundred and sixty Hong Kong Chinese children (152 in each) of A. Control group, B. BLT only group, C. BLT and Defocus Incorporated Multiple Segments (DIMS) group, D. BLT and atropine 0.01% group) and E. Atropine 0.01% group aged 7-12 years old will be recruited. They must not have had prior or current myopia control treatment, have no ocular or systemic diseases/abnormalities that affect visual function, refractive development or spectacle lens wear, and no previous intraocular or corneal surgery. They must not have allergy to atropine. The eligible subjects will be randomly assigned into one of the four groups. Their cycloplegic refraction and axial length will be monitored every six months for 2 years. The changes in refractive errors and axial length between groups will be compared.

Official Title
-----------------
Effectiveness of Bright Light Therapy, Myopic Defocus, Atropine and the Combinations for Controlling Myopic Eye Growth in Schoolchildren: A Randomized Control Trial

Conditions
-----------------
Myopia

Intervention / Treatment
-----------------
* Other: High intensity light box for bright light therapy and single vision spectacle lenses
* Other: High intensity light box for bright light therapy and Defocus Incorporated Multiple Segments (DIMS) spectacle lenses
* Other: High intensity light box for bright light therapy and atropine 0.01% eye drop and and single vision spectacle lenses
* Other: Atropine 0.01% eye drop and and single vision spectacle lenses


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Myopia of at least -0.75D (spherical equivalent) in both eyes Age at enrolment: 7-12 year; Hong Kong Chinese Astigmatism and anisometropia: 1.50D or less Spectacle corrected monocular visual acuity (VA): 0.0 logMAR or better Parents' understanding and acceptance of random allocation of grouping and masking Able to wear the prescribed spectacle, put on eye drop and undergo light therapy daily. Exclusion Criteria: Eye disease or binocular vision problems (e.g., strabismus, amblyopia, oculomotor nerve palsies, corneal disease, etc.) Previous intraocular or corneal surgery Systemic disease that may affect vision, vision development (e.g. endocrine, cardiac and respiratory diseases, diabetes, Down syndrome, etc.) Allergy to atropine Previous gas permeable, soft bifocal, or orthokeratology contact lens wear or bifocal/PAL/specific myopic control spectacle wear or use of atropine or pirenzepine (longer than 1 month of wear) Previous or current participation in myopia control studies

Ages Eligible for Study
-----------------
Minimum Age: 7 Years
Maximum Age: 12 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Control<br>Subjects in control will receive single vision spectacle lenses and a placebo desk lamp | |
| Experimental: BLT monotherapy<br>Subjects in BLT monotherapy group will receive a high intensity light box for bright light therapy and single vision spectacle lenses | Other: High intensity light box for bright light therapy and single vision spectacle lenses<br>* High intensity light box for bright light therapy and single vision spectacle lenses<br>|
| Experimental: BLT and DIMS<br>Subjects in BLT and DIMS group will receive a high intensity light box for bright light therapy and Defocus Incorporated Multiple Segments (DIMS) spectacle lenses | Other: High intensity light box for bright light therapy and Defocus Incorporated Multiple Segments (DIMS) spectacle lenses<br>* High intensity light box for bright light therapy and Defocus Incorporated Multiple Segments (DIMS) spectacle lenses<br>|
| Experimental: BLT and atropine<br>Subjects in BLT and atropine group will receive a high intensity light box for bright light therapy, single vision spectacle lens, and atropine 0.01% eye drop (twice a day) | Other: High intensity light box for bright light therapy and atropine 0.01% eye drop and and single vision spectacle lenses<br>* High intensity light box for bright light therapy and atropine 0.01% eye drop and and single vision spectacle lenses<br>|
| Experimental: Atropine monotherapy<br>Subjects in atropine group will receive atropine 0.01% eye drop (twice a day) and single vision spectacle lenses | Other: Atropine 0.01% eye drop and and single vision spectacle lenses<br>* Atropine 0.01% eye drop and and single vision spectacle lenses<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cycloplegic Refraction Change in spherical equivalent refraction (SER) | Change in cycloplegic SER (in diopter) will be measured using an open field autorefractor | Baseline and 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Axial length | Axial length (mm) will be measured after cycloplegia using a non-contact optical biometer | Baseline and 2 years | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Myopia control, Bright light, Myopic defocus, Atropine