Sustained Effect of Red-light Therapy for Myopia Control: A 2-Year Post-Trial Follow-up Study

Retrospective,2-Year Post-Trial Follow-up Study of Sustained and Rebound Effect of Red-light Therapy for Myopia in Ningbo.

To evaluate the long-term efficacy and safety of red-light therapy for myopia control over 2 years, and the potential rebound effect after treatment cessation.

The Chinese myopic children who originally completed the one-year randomised controlled trial in the previous study were enrolled. Children continued or started to daily usage of red-light therapy were defined as the RL group, while those who stopped using red-light therapy and switched to single-vision spectacles (SVS) as well as those who continued to keep single-vision spectacles in the second year were both regarded as the SVS group. Red-light therapy was provided by an at-home desktop light device emitting red-light of 650 nm and was administered for 3 min at a time, twice a day. Changes in axial length (AL) and cycloplegic spherical equivalence refraction (SER) are to be measured and compared as well as the adverse effects including the rebound effect.

Red-light therapy has emerged as a novel myopia control treatment modality recently. A 12-month randomised controlled trial (RCT) conducted by our research team was thought to be earlier to evaluate the treatment of myopic children using red-light therapy. The trial demonstrated that PBM therapy was effective on myopia control, reducing axial elongation and spherical equivalence refraction (SER) progression 103% and 127% compared with single vision spectacle (SVS) over a 12-month period, respectively. The promising efficacy of red-light therapy has been further confirmed in other studies. In addition, satisfactory user acceptability and no unrecovered functional and structural damages were observed.

Myopia generally progresses throughout childhood and hence a study duration of 1 year is not sufficient to widely adopt the red-light therapy as a treatment strategy for myopia control. The sustainability of treatment efficacy, rebound phenomenon upon cessation of treatment, and potential risks and adverse effects in myopic children with longer-term PBM therapy, remain to be fully elucidated.

Thus, the aims of this post-trial follow-up study were to invite the participants to come back for a 24-month visit and to investigate the long-term efficacy and safety of continued red-light therapy as well as the potential rebound effect following red-light treatment cessation.

Study Overview

• Status: Active, not recruiting
• Conditions: Myopia
• Intervention / Treatment: Device: Red-light therapy device; Device: Spectacles

Detailed Description

Interventions and visits All spectacle lenses were made for single focus with full correction for each subject as the first intervention throughout the whole procedure for both groups. PBM therapy was performed with a low-intensity laser (LD-A, Jilin LD Optoelectronics Technology, Jilin, China) with an irradiance of 0.35 ± 0.02 mW/cm2, a wavelength of 650 nm ± 10 nm, and illumination of approximately 400 lux on average at the first 12 month. At the second 12 months, non-randomized cohorts continued according to the willing to use the device from both groups. Once decided, those usage would be followed up for another 12 months for tracking the change of axial length as well as the change of refractive error. All the adverse effects and any harms are encouraged to report during the next 12 months' study.

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Zhejiang
    • Ningbo, Zhejiang, China, 315000
      • Ningbo Eye Hospital

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Clinical diagnosis of myopia;
2. Ages of 9~13 years old;
3. Must be with best corrected visual acuity ≥20/25 (decimal record);
4. Must be the subject in the previous study of 12-month red-light therapy of myopia;

Exclusion Criteria:

1. Clinical diagnosis of glaucoma or retinal lesions;
2. Clinical diagnosis of optic media lesions (e.g., central thick corneal scars, cataract);
3. Clinical diagnosis of optic nerve dysfunction;
4. Clinical diagnosis of amblyopia;
5. Must be eligible for follow-up.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: red-light therapy group; The red-light therapy group would be treated with red-light therapy twice daily including the single focus spectacles during the follow-up.	Device: Red-light therapy device; Red-light therapy was performed with a low-intensity laser (LD-A, Jilin LD Optoelectronics Technology, Jilin, China) with an irradiance of 0.35 ± 0.02 mW/cm2, a wavelength of 650 nm ± 10 nm, and illumination of approximately 400 lux on average.; Other Names: Repeated low-level red-light (RLRL) therapy; Low intensity red light (laser) therapy; Photobiomodulation therapy (PBM) therapy; Device: Spectacles; Single focus spectacles, that is to say, wearing glasseses with minus power lens
Other: control group; The control group including both the stopping red-light therapy group from the first 12 months (who obtained red-light therapy but stopped during the second 12-month follow-up) and those never use red-light therapy.	Device: Spectacles; Single focus spectacles, that is to say, wearing glasseses with minus power lens

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change of axial length (mm) with the measurement of device named by IntraOcular Lens Master(IOLmaster 500)	The change of axial length (mm) from the 24 months and 12 months from the baseline for each subject; The right eye were considered for the comparison between groups. The change value is recorded of the average from 5 values at the same follow-up	12-month

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change of refractive error (D) with cycloplegic refraction with the same autorefractor	The change of refractive error (D) from the follow-up of each 12-month from the baseline. The right eye were considered for the comparison	12-month

Collaborators and Investigators

• Sponsor: Beijing Airdoc Technology Co., Ltd.
• Collaborators: Ningbo Eye Hospital
• Investigators: Study Chair: LEI ZHOU, M.D., Ningbo Eye Hospital

Publications and helpful links

General Publications

• Zhou L, Tong L, Li Y, Williams BT, Qiu K. Photobiomodulation therapy retarded axial length growth in children with myopia: evidence from a 12-month randomized controlled trial evidence. Sci Rep. 2023 Feb 27;13(1):3321. doi: 10.1038/s41598-023-30500-7.

Helpful Links

• The first 12-month follow-up report of PBM therapy

Study record dates

Study Major Dates

• Study Start (Actual): May 13, 2020
• Primary Completion (Estimated): December 31, 2024
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: January 20, 2024
• First Submitted That Met QC Criteria: January 20, 2024
• First Posted (Actual): January 30, 2024

Study Record Updates

• Last Update Posted (Actual): February 14, 2024
• Last Update Submitted That Met QC Criteria: February 12, 2024
• Last Verified: February 1, 2024

More Information

Terms related to this study

• Keywords: myopia, red-light therapy
• Additional Relevant MeSH Terms: Eye Diseases; Refractive Errors; Myopia
• Other Study ID Numbers: Ningbo EYE Hospital

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