Efficacy and Safety of the New Defocus Spectacle Lens in Preventing Progression of Myopia

Study Overview
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Brief Summary
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The clinical effects of new technical spectacles with refractive correction function are mixed. A randomised trial is designed to compare the effects of new defocusing spectacle lenses and traditional aspheric spectacle lenses on myopia progression in Chinese children aged 6-14 years.

Detailed Description
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Myopia has become the focus of global attention. There has been a lot of evidence that soft bifocal contact lenses, corneal plastic lenses, low-concentration atropine and outdoor time can reduce the incidence and progress of myopia, while the clinical effects of new technical spectacles with refractive correction function are mixed. Among the strategies of myopia control through optical intervention, the clinical researches of the bifocal spectacle lens showed that the myopia progression can be slowed by about 50% in two years. However, for active children, wearing 1.50D binoculars may increase the risk of injury caused by falls. Moreover, DIMS (Defocus Incorporated Multiple Segments) spectacle lens which also reported that myopia can be effectively controlled is the effect of reducing the far-sighted defocus of omnidirectional off-axis aberration. Although the DIMS lens do not have the discomfort of wearing like the bifocal lens, because several small defocusing areas divide the imaging, the field of vision will feel uncomfortable vibration, or feel scattered light, which will hinder the field of vision. Like DIMS lens, defocus spectacle lens aims to suppress hyperopia defocus caused by omni-directional off-axis aberration. The method is to set the focal depth extension area and optical center (refractive correction area) of astigmatism with relatively positive refractive power in the surrounding concentric circle area. The precise focusing position of astigmatism, that is, the defocusing amount of the forward refractive force as the equivalent spherical lens, is about 2.75D as the same as the DIMS lens. The change from the two straight focus lines in the front and back directions of astigmatism to the point image distribution of precise focus is very gentle, so there will be no sharp point image change like the DIMS lens, which can inhibit the discomfort of the field of vision being divided. This study plans to design a randomised trial to compare the effects of new defocusing spectacle lenses and traditional aspheric spectacle lenses on myopia progression in Chinese children aged 6-14 years.

Official Title
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Efficacy and Safety of New Defocus Spectacle Lens in Preventing Progression of Myopia Compared With the Conventional Single-vision Spectacle Lens: a Randomized Controlled Trial Among Chinese Children

Conditions
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Myopia

Intervention / Treatment
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* Other: New defocus spectacle lenses
* Other: Convenional aspheric single-vision spectacle lenses


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 6 to 14 years; Under the condition of bilateral cycloplegic autorefraction, the spherical refractive error of -1.00 to -3.50 D in each eye and astigmatism of not more than 1.50 D and anisometropia of not more than 1.00 D; Best-corrected visual acuity of equal or better than 0.00 LogMAR (>= 1.0 as Snellen). The intraocular pressure of 10 to 21mmHg. Volunteer to participate in this clinical trial with signature of the informed consent form. Exclusion Criteria: History of eye injury or intraocular surgery; Clinically abnormal slit-lamp findings Abnormal fundus examination Ocular disease, such as uveitis and other inflammatory diseases, glaucoma, cataract, fundus diseases, eye tumors, dominant strabismus, and any eye diseases that affect visual function; Systemic diseases causing low immunity (such as diabetes, Down's syndrome, rheumatoid arthritis, psychotic patients or other diseases that researchers think are not suitable for wearing glasses); Participation of the drug clinical trial within three month and the device clinical trial within one month; Only one eye meets the inclusion criteria; Unable to have regular follow-up Participation of any myopia control clinical research trial within three months, and currently using rigid contact lenses (including nursing products), multifocal contact lenses, progressive multifocal lenses and other specially designed myopia control lenses, atropine drugs, etc.

Ages Eligible for Study
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Minimum Age: 6 Years
Maximum Age: 14 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: New defocus spectacle lens<br>The children in the experimental group will wear new defocus spectacle lens and receive follow-up examinations every half year. | Other: New defocus spectacle lenses<br>* The children in the new defocus spectacle lens group will wear new defocus spectacle and receive follow-up examinations every half year.<br>|
| Active Comparator: Conventional aspheric single-vision spectacle lenses<br>The children in the control group will wear conventional aspheric single-vision spectacles and receive follow-up examinations every half year. | Other: Convenional aspheric single-vision spectacle lenses<br>* The children in the convenional aspheric spectacle lenses group will wear conventional aspheric single-vision spectacle and receive follow-up examinations every half year.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes of spherical equivalent refraction (SER) at one year | The difference of SER (Diopter) at one year compared with baseline SER. SER will be measured after cycloplegia. | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes of axial length (AL) at one year | The difference of AL (mm) at one year compared with baseline AL. AL will be measured by IOLMaster-700. | 1 year | 
| Change of anterior chamber depth (ACD) at one year | The difference of ACD (mm) at one year compared with baseline ACD. ACD will be measured by IOLMaster-700. | 1 year | 
| Change of lens thickness (LT) at one year | The difference of LT (mm) at one year compared with baseline LT. LT will be measured by IOLMaster-700. | 1 year | 
| Change of corneal power (CP) at one year | The difference of CP (diopter) at one year compared with baseline CP. CP will be measured by IOLMaster-700. | 1 year | 
| Best corrected visual acuity（BCVA） at one year | BCVA will be measured at baseline and one year by EDTRS visual acuity chart. | 1 year | 
| Binocular visual function at one year | Binocular visual function which is a qualitative outcome assessed by a series of tests will be measured every half year. | 1 year | 
| Choroidal thickness at one year | The difference of Choroidal thickness (μm) at one year compared with baseline measure. Choroidal thickness will be measured by OCTA. | 1 year | 
| Visual scale score at six months | Visual scale score measured by the Chinese version of the pediatric refractive error profile2 (PREP2) and is scaled from 0 (poor quality of life) to 100 (good quality of life). | 6 months | 
| Visual scale score at one year | Visual scale score measured by the Chinese version of the pediatric refractive error profile2 (PREP2) is scaled from 0 (poor quality of life) to 100 (good quality of life). | 1 year | 
| Time length of wearing spectcales at one year | Time length of wearing spectcales will be collected every half year. Participants will report the approximate time of wearing glasses per day and days per week. | 1 year | 
| Safty of wearing the spectacle lens | Safty of wearing the spectacle lens which is a qualitative outcome will be evaluated every half year by prespecified measures and definations through symptoms and signs, intraocular pressure#slit lamp and ocular fundus checks. | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Defocused lens, Myopia control