LED Light Therapy… Through Your Ears?
Valkee, the inventor of the bright-light headset, and scientists from the University of Oulu published the first results of a clinical and neurobiological research program conducted since 2007, on the human brain’s light sensitivity. The clinical trial, published in the unconventional journal Medical Hypothesis, studied therapeutic effects of bright light channeled into the human brain via the ear canal.
The existing paradigm suggests that light therapy is only effective when transmitted through the eyes. The results of this clinical trial published in Medical Hypothesis challenge this.
“There is no conclusive evidence that light therapy is only transmitted through the eyes. On the contrary, in mammals, a significant amount of light penetrates the skull and reaches the brain. The brain has photoreceptive proteins such as encephalopsin, and physiological influences have been measured by extra-ocular light exposure. Therefore, we challenged the existing paradigm by showing that the brain-targeted bright light therapy via the ear canal is an effective mechanism to relieve seasonal depression,” commented Juuso Nissilä, Valkee’s co-founder and chief scientist.
In the published trial, patients received 8-12 minutes of 6.0-8.5 lumen bright light daily into both ear canals for 4 weeks with a medical Class II(a) device manufactured by Valkee Ltd., called bright light headset. The daily administration time was personalized at the study clinic.
“The results are strong and promising: 92% of the patients with severe seasonal affective disorder achieved full remission measured by the self-rated BDI-21 questionnaire. With the psychiatrist-rated HAMD-17 questionnaire, 77 % of the patients achieved full remission,” commented Professor Markku Timonen, the lead investigator for the published trial at the University of Oulu. The full remission criteria was BDI-21 and HAMD-17 sum score ≤ 7.
Valkee introduced its bright-light headset in August 2010 and now has a broad user base. Based on cross-functional science in neurology, biology, psychiatry, and physiology, Valkee is a CE-certified Class II(a) medical device under the EU regulations.
From the research
The stated purpose of the peer-reviewed Medical Hypotheses journal is to publish interesting theoretical papers. The journal considers radical, speculative, and non-mainstream scientific ideas. The abstract of the article states:
…it is hard to believe that our findings could be explained solely by placebo effect. Consequently, the basic assumptions underlying extraocular photoreception in humans deserve to be reconsidered. Given that a proper placebo treatment can be implemented via ear canals, further investigations with randomized placebo-controlled and/or dose-finding study designs regarding the extraocular transcranial bright light in the treatment of SAD are called for.
Citation: Timonen M et al. Can transcranial brain-targeted bright light treatment via ear canals be effective in relieving symptoms in seasonal affective disorder? – A pilot study. Med Hypotheses (2012), doi:10.1016/j.mehy.2012.01.019. View more details and download the article (for a fee) at www.sciencedirect.com/science/article/pii/S0306987712000308
The University of Oulu, one of the largest universities in Finland, is an international research and innovation university engaged in multidisciplinary basic research and academic education. The University cooperates closely with industry and commerce, and has broad connections with hundreds of international research and educational institutions. The study fields include Humanities, Education, Economics and Business, Science, Medicine, Dentistry, Health Sciences, and Technology. For more information visit www.oulu.fi/english/
Prior to the two clinical trials in seasonal affective disorder conducted with the University of Oulu, Valkee has presented that the human brain responds to light via ear canal (fMRI data on activation of brain networks presented at ISMRM 2011) and that the human brain, not just the visual system, is sensitive to light (localization of OPN3 photoreceptor proteins broadly in 18 brain sites presented at Scandinavian Physiology Society Annual Meeting 2011).