Introduction Pathologic myopia (PM) is a leading cause of irreversible blindness worldwide, yet effective therapeutic interventions remain limited. Although repeated low-level red light (RLRL) therapy has demonstrated significant efficacy in controlling myopia progression among children, its application in patients with PM remains unexplored. This study aims to evaluate the regulatory effects of RLRL on choroidal vascular density and thickness in patients with PM and verify its safety and efficacy in delaying the progression of fundus atrophic lesions. Methods and analysis This is a prospective, randomised, controlled trial enrolling 158 patients with PM aged 18–55 years. Participants will be randomised (1:1) to an intervention group or a control group. The intervention group will receive light-emitting diode–based RLRL therapy (wavelength, 660 nm; power density, 65 mW/cm²) administered two times daily for 3 min per session, 5 days per week, over a 12-month period. The control group will receive a sham treatment (power density, 5 mW/cm²) following an identical schedule. The primary outcome measure is the change in choroidal vascular density and choroidal vessel volume index at 12 months. Ethics and dissemination This study has been approved by the Ethics Review Committee of Shanghai Eye Disease Prevention and Treatment Centre (EC-20250506-04). This study will be conducted in adherence to the approved protocol, Good Clinical Practice and the Declaration of Helsinki. The study results will be submitted to a peer-reviewed journal and presented at both local and international congresses. Trial registration number NCT07312214
Zhang et al. (Wed,) studied this question.