Photobiomodulation therapy for congenital color vision deficiency: results of a preliminary randomized clinical trial

Purpose: This study presents a novel randomized controlled trial investigating photobiomodulation (PBM) therapy as an intervention method for color vision deficiency (CVD).

Methods: A total of 74 participants with CVD were assigned to either the PBM group or the control group. In the PBM group, participants wore virtual reality (VR) goggles twice daily, with a 12-h interval, over a four-week period. The VR video consisted of alternating red and green images, each presented for 5 s, totaling 6 min and 20 s. No treatment was administered to the control group. Color vision improvement was assessed using Yu's, Ishihara's pseudoachromatic plates, Color Blindness Check (CBC), and FM-100 Hue total error score (TES).

Results: After 4 weeks, in terms of Yu's and Ishihara's Plates, the patients in PBM group could identify increasing pieces (before: 1.6 ± 1.6, 2.3 ± 2.2; 4 weeks: 6.5 ± 4.4, 5.4 ± 2.9), while in control group, the number was before: 2.6 ± 3.4, 2.6 ± 2.5; 4 weeks: 3.3 ± 3.6, 2.9 ± 2.2. As for CBC scores, the patients in PBM also showed improved high scores (before: 2353.3 ± 700.0; 4 weeks: 2693.6 ± 642.5). Moreover, PBM treatment resulted in a significant reduction of FM-100 scores (before: 298.0 ± 211.3; 4 weeks: 202.1 ± 114.4).

Conclusion: These findings suggest that PBM therapy holds promise as a potential treatment option for individuals with CVD.

Clinical trial registration: The study received approval from the Ethics Committee of PLA General Hospital, China (KY2021-017). Additionally, it was registered as a Chinese domestic clinical trial (ChiCTR2200056761) at "http://Chictr.org.cn/index.aspx".