Clinical Study of Light Therapy to Control Myopia Progression in Children

Study Overview
=================
Brief Summary
-----------------
Low-lever red light therapy (LLLT) has been used to control myopia progression in China for a few years besides amblyopia therapy for a few decades. This study is to test the efficacy of PBM therapy to myopia children as well as to compare two types of PBM therapy to control myopia progression within one month.

Detailed Description
-----------------
LLLT utilized the 650-nm red light to provide sufficient energy to stimulate the tissue without causing damage to the surrounding tissues. And several researchers reported the long-term efficacy of LLLT in slowing the progression of myopia to date. These studies were reported various illumination and irradiance. This study is to test the efficacy of LLLT comparing to the control group as well as to test whether two types of lighting design will be different to the efficacy and safety.

Official Title
-----------------
Clinical Study of Low Lever Red Light Therapy With 650nm to Control Myopia Progression in Children

Conditions
-----------------
Myopia, Progressive

Intervention / Treatment
-----------------
* Device: Photobiomodualtion Therapy
* Device: Single vision spectacles for correction myopia


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Grade 1 to grade 9 and age 6 to 16 years (including 6 and 16 years), Sex is not limited; Equivalent sphere (SER): -0.50D   -6.00D (including-0.50 and-6.00D); Best corrected vision in one eye under glasses correction: 0.1 log MAR; No strabismus: no more than 15 prism constant dominance strabismus after far and near cover tests; No myopia control measures within the previous 4 weeks: such as orthokeratology lens, gradient lens, double light lens, eye drops for myopia control (such as atropine), myopia defocus glasses, red light for myopia control, other specially designed myopia light treatment instruments or contact lenses for special design to control myopia (such as Misight); Exclusion Criteria: Any ocular(including constant dominant strabismus with more than 15 prisms) and systemic diseases or abnormalities can significantly affect visual function or promote the progression of myopia; Other interventions for myopia control before 4 weeks before enrollment, For example, orthoplastic lens, gradient lens, dual-light lens, eye drops for myopia control (atropine), myopia defocus glasses, red light therapy devices for myopia control, other specially designed comprehensive treatment devices, myopia, amblyopia, or specially designed contact lenses (such as Misight), etc. Subject participated in other clinical trials within 4 weeks before the enrollment; The investigator for safety reasons or the interests of the patient, Other circumstances in which the patient should not participate in this trial, If suffering from serious heart, liver and kidney disease. -

Ages Eligible for Study
-----------------
Minimum Age: 6 Years
Maximum Age: 16 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
Interventional Model Description: Low lever red light therapy with Model : Sky-n1201c at the wavelength of 650nm; 3 minutes illumination for both eyes, administered twice daily at the interview of 4 hours. Children in the red light therapy group wore single vision spectacles the entire day and under red light therapy (power, 0.6mW; wavelength, 650nm; Beijing Airdoc MPC Co. Ltd, Beijing, China) twice per day for 3 minutes each session, with at least a 4-hour interval between sessions. There were no specific guidelines for room illumination. After the first measurement session, each child returned for follow-up examinations at 1, 3, and 6 months and completed all the aforementioned examinations.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: PBM therapy 1<br>PBM therapy was performed with a low-intensity laser (Airdoc, MPC Co.,Ltd., Beijing, China) with an irradiance of 0.6±0.2 mW, a wavelength of 650 nm±10 nm, and illumination of approximately 400 lux on average. The lighting spot for therapy is a dot. Only one eye will be treated with PBM therapy. | Device: Photobiomodualtion Therapy<br>* low lever light therapy with laser semi-conductor at wavelength of 650nm<br>* Other names: Myopia light therapy; Low lever light therapy; Low lever laser therapy; Low intensity red light thearpy;Device: Single vision spectacles for correction myopia<br>* Provide the distance best corrected vision acuity of refractive error of myopia for all the groups<br>* Other names: Glasseses;|
| Experimental: PBM therapy 2<br>PBM therapy was performed with a low-intensity laser (Airdoc, MPC Co.,Ltd., Beijing, China) with an irradiance of 0.3±0.2 mW, a wavelength of 650 nm±10 nm, and illumination of approximately 400 lux on average. Only one eye will be treated with PBM therapy. | Device: Photobiomodualtion Therapy<br>* low lever light therapy with laser semi-conductor at wavelength of 650nm<br>* Other names: Myopia light therapy; Low lever light therapy; Low lever laser therapy; Low intensity red light thearpy;Device: Single vision spectacles for correction myopia<br>* Provide the distance best corrected vision acuity of refractive error of myopia for all the groups<br>* Other names: Glasseses;|
| Placebo Comparator: Control<br>Single vision spectacles correction only. | Device: Single vision spectacles for correction myopia<br>* Provide the distance best corrected vision acuity of refractive error of myopia for all the groups<br>* Other names: Glasseses;|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in axial length (mm） | Changes of axial length at 1-Month follow-up from baseline with IOLmaster 500 Axial length measurement at baseline and at follow-up with IOLmaster(Carl Zeiss). Five measurements were taken and averaged. The changes will be calculated by the formula as below: Change in axial length ( mm ) = Axial length value at follow-up baseline | at 1-month Follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in cycloplegic autorefraction (diopters, D) | Objective refraction measured by using Autorefractor. Five measurements are obtained for each eye and the average of spherical equivalence was used for statistical analysis. The measurements will be both with cycloplegia at baseline and at follow-up. The changes in cycloplegic autorefraction are calculated in the mean value of each group. | at 1-month Follow-up and at baseline | 
| Changes of choroidal thickness under macular foveal (um) | Swept-source optical coherence tomography (OCT) and OCT angiography were used To measure choroidal fovea thickness at baseline and at follow-up. To avoid the effects of circadian rhythm on the results, OCT scanning was performed twice by the same investigator between 8:00 A.M. and 2:00 P.M. at baseline and 1-month follow-up. Two independent skilled professionals measured the sub-foveal choroidal thickness （SFChT) using a linear measurement program during the OCT scan. To increase the visibility of the choroid, the enhanced depth imaging mode was used. We defined the thinnest part of the macula in the image as the fovea. The SFChT was measured from the outermost part of the retinal pigment epithelium to the inner layer of the the choroidoscleral interface. | at 1-month Follow-up and at baseline | 
| Changes of cornea power | Changes in the central anterior cornea power by the value measured from auto-refraction. The mean values will be recorded as well as the mean values at follow-up of 1 month | at 1-month Follow-up and at baseline | 
| Change in retina fovea perfusion density (RFPD, %) | Swept-source optical coherence tomography (OCT) angiography is used to measure retina fovea perfusion density (RFPD). The TowardPi OCTA allow for the in vivo visualization of three-dimensional (3-D) vascular networks in the retina and choroid. The OCTA images were acquired by the TowardPi-3D spatial identification algorithm. The retina vessels and choriocapillaris were identified by higher order moments decorrelation algorithm. The medium- and large-sized choroid vessels from Sattler's layer and Haller's layer were visualized by 3D threshold segmentation algorithm. In this study, the retinal and choroidal images were obtained with an area of 18*18 mm centered on the fovea. In addition, for a comprehensive analysis of the macular zone, we adopted the Early Treatment Diabetic Retinopathy Study (ETDRS) grid using the instrument's software which was adjusted for each individual participant's ocular magnification. | at 1-month Follow-up and at baseline |