Robotrak 博视医疗

A new study led by Dr. Kai Wang from the Department of Ophthalmology, Peking University People's Hospital and Dr. Hongxin Song from Beijing Tongren Hospital has been published in JAMA Ophthalmology. This research focused on the effects of repeated low-level red light (RLRL) therapy on myopic children's retinas.

Background And Method

The global prevalence of myopia is on the rise, especially among children and adolescents. RLRL therapy has shown potential in controlling myopia progression, but its long-term impact on retinal photoreceptors remains unclear. To address this, the research team conducted a retrospective multicenter cohort study. They recruited 99 myopic children, divided into an RLRL group (52 children) and a control group (47 children). The team used the AOSLO system (Robotrak Technologies, Nanjing, China) to measure cone photoreceptor density along 4 retinal meridians. This system has a navigation system to help localize the imaging area and uses a multiplane independent refractor lens to correct wavefront aberrations, ensuring high-quality image acquisition.

FIG1: Distance-Density Distribution Plots of Paracentral Foveal Cone Photoreceptors in Participants Along Nasal, Temporal, Superior, and Inferior Meridians. RLRL indicates repeated low-level red light.

Results

The study results showed that RLRL users had a decreased cone density within 0.5 mm eccentricity from the foveal center, especially in the temporal region. For example, at 0.3 mm temporal eccentricity, the RLRL group had a significantly lower cone density, with a mean difference of -2.1×10³ cells/mm² compared to the control group (P = 0.003). Additionally, 11 eyes of 10 participants showed abnormal low-frequency, high-brightness signals near the fovea, and the odds ratio of such abnormal signals in RLRL users was 7.23 times higher than non-users (P = 0.02). One participant in the RLRL group had small cystoid abnormalities in the ganglion cell layer, which disappeared 3 months after discontinuing RLRL therapy.

FIG:2 Adaptive Optics Scanning Laser Ophthalmoscopy (AOSLO) Images showing abnormal low-frequency high-intensity cell clusters in the fovea (A-C, yellow asterisks) compared with a normal fovea (D). Complete set of images is detailed in eFigure 3 in Supplement 1. RLRL indicates repeated low-level red light.

FIG3: Macular Foveal Cone Images in the Optical Coherence Tomography (OCT) of Repeated Low-Level Red Light (RLRL) Results, Including Baseline and Follow-Up. A, Fundus photography and a schematic cross-section of the OCT scans of the participant (yellow arrow). B, OCT images of the participant’s initial eye examination (top) and 3 months after discontinuation of RLRL (bottom). The white arrowhead in the yellow box shows the cystoid cavity in ganglion cell layer. C, Adaptive optics scanning laser ophthalmoscopy (AOSLO) images show montage formation near the fovea at the participant’s initial ophthalmologic examination. The white arrowhead shows the cystoid cavity in ganglion cell layer. D, AOSLO image of the participant’s review image after discontinuation of RLRL for 3 months. The white arrowhead shows the corresponding position of the previous cystoid cavity.

Summary

This study indicates that RLRL therapy for at least 1 year may be linked to reduced cone density in the paracentral fovea and other subtle retinal abnormalities in some myopic children. Although RLRL therapy shows promise in controlling myopia, its long-term safety and efficacy need further exploration. AOSLO assessment may serve as an important tool for evaluating the efficacy and safety of RLRL therapy.