Short-Term Exposure to Violet Light Emitted from Eyeglass Frames in Myopic Children: A Randomized Pilot Clinical Trial

Abstract

Violet light (VL), 360–400 nm wavelength, is contained in the sunlight and is an effective element for myopia suppression. This study is to investigate the safety and efficacy of novel eyeglasses that emit VL from the frames. This is a double-masked, randomized, pilot clinical trial conducted in a clinic in Japan. Forty-three children with myopia were enrolled. Participants were randomly assigned to two groups, wearing VL-emitting eyeglass frames (VLf) that emitted VL of 310 μW/cm2 (VLf group, n = 22) or pseudo-placebo eyeglass frames with a minimal emission of VL (<10 μW/cm2) (control group, n = 21). The exposure time was 3 h per day. The primary outcomes were visual acuity, tear film break-up time, corneal endothelial cell density, and the slit-lamp/fundus examinations. The secondary outcome was the 6-month changes in the axial lengths and cycloplegic refractions. Forty-one (95%) participants were included; twenty-one in the VLf group and twenty in the control group. No significant differences were seen in any safety evaluation. Significant changes were seen in axial elongation, choroidal thickness, and cycloplegic refractions in the subgroup analysis of 8- to 10-year-old children (p < 0.05), but otherwise no significant differences were seen. The VLf showed short-term safety and effectiveness against myopia progression.

Myopia Is an Ischemic Eye Condition: A Review from the Perspective of Choroidal Blood Flow

“…Simultaneously, the prevalence of UV light overprotection has led to no VL indoors. A recent randomized controlled trial (RCT) has shown that short-term exposure to violet light could be effective in inhibiting the progression of myopia and leading to a significant increase in the ChT [97]. We reported that exposure to VL in the 360-400 nm range can upregulate the gene early growth response protein (EGR-1) expression and slow myopia progression [98].…”

“…This figure shows the choroidal blood flow change and myopia correlation. (A) Normal choroidal perfusion and normal choroidal thickness; (B) studies proved a reduction in choroidal perfusion leads to a decrease in choroidal thickness and axial elongation; (C) anti-myopia treatment and increased perfusion lead to choroidal thickness maintenance and suppression of axial elongation.Created with graphics from ©BioRender (biorender.com)[9,10,19,32,50,56,57,67,69,97,98,100].…”

Red light therapy for myopia: Merits, risks and questions

“…34 Paradoxically, in experiments involving human subjects, short-term (1 h) exposure to monochromatic blue (460 nm) lighting also resulted in a reduction in axial length, while increases in axial length and choroidal thinning were observed after 1 h in green (521 nm) and red (623 nm) monochromatic lighting. 35 Furthermore, Tsubota and colleagues hypothesised that exposure to 'violet light' (<400 nm) would inhibit myopia in children, reporting preliminary data in support of this idea, 36 although only a fraction of light at such short wavelengths is expected to penetrate the human ocular media and so reach the retina. Interestingly, data from chickens indicate that they respond more 'like the humans', 35 becoming more myopic when reared in red light.…”

Smart Devices in Optometry: Current and Future Perspectives to Clinical Optometry

“…There is a growing evidence which indicate that specific wavelengths of light may play a probable role in controlling myopia. 103 Apart from the low level repeated red-light therapy through desktop-based device, 104 there are a few wearable devices for myopia control that are developed to emit monochromatic light: violet light from eyeglass frames, 102 and blue light simulation of optic nerve head using virtual reality headset, 105 which are currently being investigated in the myopia clinical trials. There is a wide scope for the wearable light therapy devices as myopia control intervention, in addition to optical and pharmaceutical interventions.…”