Safety Evaluation of 4 Red Light Therapy Devices for Myopia

Red laser therapy (ie, repeated low-level red light) has emerged as an intervention for myopia, with widespread clinical use in Asia and increasing international consideration. However, the ocular safety of commercially available devices has not been rigorously evaluated.

To assess the optical output and safety classification of 4 commercially available red light therapy devices for myopia management using American National Standards Institute (ANSI) guidelines.

This quality improvement study consisted of a laboratory-based evaluation of the Sky-n1201, Future Vision, EyeRising, and AirDoc instruments and was performed from November 25, 2023, to April 30, 2024. Radiometric power was measured with an integrating sphere radiometer at 1- and 10-cm distances through a 7-mm aperture and retinal irradiance calculated for 2- to 7-mm pupil diameters. Safety classification was investigated according to ANSI Z80.36-2021 and ANSI Z136.1-2022 standards. Data were analyzed from November 25, 2023, to September 10, 2024.

The main outcome was assessing the time to the group 1 safety limit and the ANSI device classification. This was measured by laboratory-based evaluation of 4 instruments and measuring radiometric power at various pupil diameters.

The Sky-n1201 and EyeRising devices reached ANSI group 1 limits within exposure times of 2.8 and 1.4 seconds, respectively, for a 7-mm pupil and are classified as Class 1 and 2M laser devices, respectively. The Future Vision device reached group 1 limits under extended exposure times of 253 seconds or longer but remained within limits for Class 1 laser classification. The light-emitting diode-based AirDoc produced diffuse illumination with a time to group 1 limit of 22 761 seconds, classifying it as group 1.

These findings suggest that laser-based red light therapy instruments deliver irradiance levels that reach ANSI safety limits within exposure times below the recommended 180-second treatment time. These findings, combined with emerging clinical reports of retinal damage and recent regulatory reclassification of red laser devices as Class III in China, highlight the need for rigorous, independent safety validation before widespread pediatric use.