Color Therapy for Myopia Management

https://www.clspectrum.com/newsletters/mastering-myopia/march-9,-2022

The eyes are the window to our soul, and with ocular light exposure therapy, we can improve vision problems like accommodative or vergence dysfunctions. This type of treatment also helps kids, who may be developing amblyopia, find their stronger visual function by increasing how much they see in all directions!1   As we know, myopia is associated with an increased risk of glaucoma, retinal detachment, and myopic maculopathy, which can lead to blindness.2 There is evidence to suggest that macular retinoschisis can be healed after photodynamic therapy for choroidal neovascularization in pathological myopic eyes.3 We know prevention is better than a cure so how can we use light therapy to slow the progression of myopia?    Time spent outdoors during childhood has been proven to lower the risk and/or slow progression of myopia.4,5 There has been a recent study that suggests myopia may be influenced by environmental light conditions.6 And it has been found that animals can perceive differences in the color and speed of flickering lights, which may affect how they emmetropize.6,7   We also know through animal research that delayed circadian rhythms and stimulus of the rod pathways with dim light can influence how the eyes grow, increasing myopia.8-10    Research has shown that red light therapy is an effective way to treat many health conditions, from anxiety attacks and depression all the way down through insomnia.11 Studies have found it stimulates complex IV of the mitochondrial respiratory chain (cytochrome c oxidase) as well increasing ATP synthesis, so you're less likely to experience fatigue or pain while using this treatment method!12 Studies also show that low level light therapy can be an effective treatment for tissue regeneration and wound healing.12,13   The colors of the blue spectrum have been shown to improve focusing abilities for near vision tasks by reducing adrenaline production, anxiety, and stress.14 This is because they stimulate our parasympathetic nervous system (PNS), which controls homeostasis in addition leading us into pupil constriction (causing stress on the ciliary body) stimulating choroidal growth, when viewing close-up objects or reading small print on documents; but in turn it stimulates axial growth. Hence the blue spectrum will not help us.15,16   The colors that stimulate the sympathetic nervous system (SNS) are orange, yellow, and red. This leads to pupil dilation which is responsible for controlling our “fight or flight” response!17 Being opposite to the PNS system, repeated low-level red-light (RLRL) therapy may be effectively used for controlling axial elongation in myopia management.17   A recent 12-month multicenter, randomized, parallel group, single blind, clinical trial in hospitals in China looked at the use, safety, and efficacy of RLRL therapy for myopia management. It was found that RLRL slowed refract error change by 0.59D, 76.6% efficacy, and axial elongation by 0.26mm, 69.4% efficacy, compared to single vision spectacles.17   It will be interesting to see if use of red tinted spectacles or red tinted contact lenses will do the trick and help manage axial length elongation in myopia management.18  References: 1. López de la Fuente C, Sánchez-Cano AI. Photometric and Colorimetric Evaluation of Phototherapy Instruments for Syntonic Treatment of Visual Anomalies. Optom Vis Sci. 2021 Dec 1;98(12):1355-1365. doi: 10.1097/OPX.0000000000001813. PMID: 34743128. 2. Wang SK, Guo Y, Liao C, et al. Incidence of and Factors Associated With Myopia and High Myopia in Chinese Children, Based on Refraction Without Cycloplegia. JAMA Ophthalmol. 2018 Sep 1;136(9):1017-1024. doi: 10.1001/jamaophthalmol.2018.2658. PMID: 29978185; PMCID: PMC6142978. 3. Lingham G, Mackey DA, Lucas R, Yazar S. How does spending time outdoors protect against myopia? A review. Br J Ophthalmol. 2020 May;104(5):593-599. doi: 10.1136/bjophthalmol-2019-314675. Epub 2019 Nov 13. PMID: 31722876. 4. Qi Y, Zhang Y, Yu J, et al. Gradual healing of macular retinoschisis after photodynamic therapy for choroidal neovascularization in pathological myopia eyes. Photodiagnosis Photodyn Ther. 2020 Dec;32:102021. doi: 10.1016/j.pdpdt.2020.102021. Epub 2020 Sep 22. PMID: 32977067. 5. Wu PC, Chen CT, Lin KK, et al. Myopia Prevention and Outdoor Light Intensity in a School-Based Cluster Randomized Trial. Ophthalmology. 2018 Aug;125(8):1239-1250. doi: 10.1016/j.ophtha.2017.12.011. Epub 2018 Jan 19. PMID: 29371008. 6. Zhang L, Guo D, Xie C, et al. The effects of colour and temporal frequency of flickering light on variability of the accommodation response in emmetropes and myopes. BMC Ophthalmol. 2021 Feb 17;21(1):88. doi: 10.1186/s12886-021-01856-z. PMID: 33596849; PMCID: PMC7890996. 7. Rucker FJ. The role of luminance and chromatic cues in emmetropisation. Ophthalmic Physiol Opt. 2013 May;33(3):196-214. doi: 10.1111/opo.12050. PMID: 23662955. 8. Landis EG, Yang V, Brown DM, et al. Dim Light Exposure and Myopia in Children. Invest Ophthalmol Vis Sci. 2018 Oct 1;59(12):4804-4811. doi: 10.1167/iovs.18-24415. PMID: 30347074; PMCID: PMC6181186. 9. Schmid SR, Höhn C, Bothe K, et al. How Smart Is It to Go to Bed with the Phone? The Impact of Short-Wavelength Light and Affective States on Sleep and Circadian Rhythms. Clocks Sleep. 2021 Oct 28;3(4):558-580. doi: 10.3390/clockssleep3040040. PMID: 34842631; PMCID: PMC8628671. 10. Sharpe LT, Fach CC, Stockman A. The spectral properties of the two rod pathways. Vision Res. 1993 Dec;33(18):2705-20. doi: 10.1016/0042-6989(93)90230-t. PMID: 8296467. 11. Hamblin MR. Shining light on the head: Photobiomodulation for brain disorders. BBA Clin. 2016;6:113-124. Published 2016 Oct 1. doi:10.1016/j.bbacli.2016.09.002 12. Salehpour F, Mahmoudi J, Kamari F, et al. Brain Photobiomodulation Therapy: a Narrative Review. Mol Neurobiol. 2018 Aug;55(8):6601-6636. doi: 10.1007/s12035-017-0852-4. Epub 2018 Jan 11. PMID: 29327206; PMCID: PMC6041198. 13. Rohringer S, Holnthoner W, Chaudary S, et al. The impact of wavelengths of LED light-therapy on endothelial cells. Sci Rep. 2017 Sep 6;7(1):10700. doi: 10.1038/s41598-017-11061-y. PMID: 28878330; PMCID: PMC5587748. 14. Minguillon J, Lopez-Gordo MA, Renedo-Criado DA, et al. Blue lighting accelerates post-stress relaxation: Results of a preliminary study. PLoS One. 2017;12(10):e0186399. Published 2017 Oct 19. doi:10.1371/journal.pone.0186399 15. Hoseini-Yazdi H, Read SA, Alonso-Caneiro D, Collins MJ. Retinal OFF-Pathway Overstimulation Leads to Greater Accommodation-Induced Choroidal Thinning. Invest Ophthalmol Vis Sci. 2021 Oct 4;62(13):5. doi: 10.1167/iovs.62.13.5. PMID: 34636878; PMCID: PMC8525845. 16. Woodman EC, Read SA, Collins MJ. Axial length and choroidal thickness changes accompanying prolonged accommodation in myopes and emmetropes. Vision Res. 2012 Nov 1;72:34-41. doi: 10.1016/j.visres.2012.09.009. Epub 2012 Sep 24. PMID: 23017772. 17. Jiang Y, Zhu Z, Tan X, et al. Effect of repeated low-level red-light therapy in myopia control in children: a multicenter randomized controlled trial. Ophthalmology. December 1, 2021. 18. Severinsky B, Yahalom C, Florescu Sebok T, et al. Red-Tinted Contact Lenses May Improve Quality of Life in Retinal Diseases. Optom Vis Sci. 2016 Apr;93(4):445-50. doi: 10.1097/OPX.0000000000000761. PMID: 26657696.