This research project is a prospective, single-arm, open-label pilot study designed to evaluate the efficacy and safety of focused LED-based repeated low-level red-light (fLED-RLRL) therapy in myopic adults. The primary objective is to assess whether the therapy can increase choroidal thickness and improve choroidal blood flow. The secondary objective is to evaluate the safety and tolerability of red light therapy in adult myopes.

The study will enroll 14 myopic adults aged 18 to 50 years, with spherical equivalent refractions ranging from -0.50 to -6.00 diopters. Participants will receive home-based fLED-RLRL therapy (wavelength 650 ± 10 nm, power 0.20 mW) twice daily for 3 minutes per session, 5 days per week, over a total of 28 days, combined with single-vision spectacles. The fLED red-light device employs a standard LED semiconductor chip integrated with a total internal reflection (TIR) lens and microlenses to deliver a precise and concentrated beam, enabling accurate focusing of light energy on the target area. A video tutorial will be provided to guide device usage, and support from the research team will be available throughout the study.

Before the treatment, baseline data will be collected from each participant. Baseline and follow-up assessments (days 7, 14, 21, 28) will include comprehensive ophthalmic examinations: visual acuity, intraocular pressure, slit-lamp examination, autorefraction and subjective refraction, optical coherence tomography (OCT), optical coherence tomography angiography (OCTA), and posterior blood flowgraphy. These assessments will monitor structural and functional changes in the retina and choroid, as well as adverse events (e.g., retinal damage, prolonged after-images).

Primary and secondary outcomes will include changes in choroidal thickness, choroidal blood flow, ocular biometric parameters, spherical equivalent refraction, and visual acuity. Additional imaging assessments, such as posterior blood flowgraphy, OCT, and OCTA scans, will also be evaluated.

This pilot study aims to preliminarily explore the safety and efficacy of an fLED red-light therapy system integrated with machine vision for myopia management by analyzing choroidal parameters over a short-term treatment period. By providing a safer alternative to current laser-based therapies, this project seeks to advance the field of myopia treatment, offering a novel solution that aligns with the increasing demand for effective and safe interventions.

Inclusion Criteria:

1. Age 18-50 years.
2. SE refractions between -0.50 and -6.00 diopters (D)
3. Astigmatism of 1.50 D or less.
4. Best corrected monocular visual acuity better than 20/20 (Snellen equivalent).
5. Willingness to provide written informed consent and comply with the treatment protocol.

Exclusion Criteria:

1. Strabismus or binocular vision abnormalities in either eye.
2. Ocular abnormalities in either eye or other systemic abnormalities.
3. Previous or current use of myopia control interventions (e.g., orthokeratology, low-dose atropine, pirenzepine) within the past 6 months.
4. History of ocular surgeries (e.g., cataract surgery and LASIK/SMILE).
5. Afterimage time > 5 minutes (contraindications to RLRL therapy).