Myopia Control With Simultaneous Vision Approach

Study Overview
=================
Brief Summary
-----------------
To determine if the 'Defocus Incorporated Soft Contact' (DISC) lens slows myopia progression in Hong Kong schoolchildren using simultaneous vision approach.

Detailed Description
-----------------
The investigators hypothesize that the natural process of emmetropization in human is regulated by the equilibrium between the opposite hyperopic and myopic defocus. A sharp focus of retinal image (foveal fixation) is fundamental for co-ordination of the equilibrium. The DISC lens is a custom-made multi-zone bifocal soft contact lens which is based on simultaneously provides clear vision and defocus at all viewing distances. It comprises of correcting zones for correcting distant prescription(correction of refractive error, and defocusing zones to incorporate constant myopic defocus for slowing down myopia progression.

Official Title
-----------------
Control of Myopia Progression in Myopic Children Using Simultaneous Vision Approach

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

Intervention / Treatment
-----------------
* Device: Defocus Incorporated Soft Contact (DISC) lens


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Age 8-13 years Myopia (SE) between -1D to -5D Astigmatism less than or equal to -1D Anisometropia: less than or equal to 1.25D aided VA (monocular): 0.00 log MAR or better willingness to wear contact lens constantly availability for follow-up for at least 2.5 years parents' understanding and acceptance willing to provide refractive status of grandparents Exclusion Criteria: Severe ocular or systemic allergies Taking any medication that might have an impact on contact lens wear or that might influence the outcome of the clinical trial Ocular or systemic condition that might affect refractive development Strabismus at distance or near Prior use of bifocal or progressive lenses Prior use of rigid gas permeable lenses and Ortho-K lenses

Ages Eligible for Study
-----------------
Minimum Age: 8 Years
Maximum Age: 13 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: single vision soft contact lens<br>Single vision soft contact lenses with same materials of the DISC lens | |
| Experimental: Defocus Incorporated Soft Contact (DISC) lens<br>The use of DISC lens to slow down the progression of myopia | Device: Defocus Incorporated Soft Contact (DISC) lens<br>* Use of simultaneous vision bifocal soft contact lenses with myopic defocus to control the progression of myopia<br>* Other names: bifocal contact lens;|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The changes of cycloplegic refractive errors | Refractive error was measured using Shin-Nippon NVision-K 5001 autorefractor The changes of cycloplegic objective refractive errors between the treatment and the control were compared. | every 6 months for 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The changes of axial length | Axial length was measured after cycloplegia using IOL Master | every 6 months for 2 years | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Myopia progression, Myopia control, Simultaneous vision, Myopic defocus