Low level laser therapy for tinnitus- does it work?

Many people ask us about the use of low level laser therapy (LLLT), also called photobiomodulation, as a treatment for tinnitus. This treatment generally involves applying low power laser energy to the inner ear either by directing the laser through the ear canal or across the bony mastoid behind the ear. It is thought by some that this laser energy can modulate the gene expression and functioning of the cells in the inner ear, thus improving tinnitus. However, there is significant heterogeneity in techniques described in the scientific literature for this purpose. If one reviews research publications on this topic, it is easy to find studies that report improvements in tinnitus using LLLT. But there is more to this picture than it seems from such a superficial review of the literature and this highlights the importance of interpreting the clinical research critically. Unfortunately, much of the research published today is significantly flawed and does not truly support the conclusions reported. There are many reasons for this shift in research quality over time, but this fact makes it crucial for reviewers of the scientific literature to have the proper knowledge and expertise to interpret the published science with a critical lens so we can draw appropriate conclusions. Did you know that there are over 30,000 scientific journals in publication? That represents a huge volume of scientific papers being published and much of the work, regrettably, is of dubious quality and reliability. Like many realms of our current media landscape, it takes a critical and discerning eye to differentiate the reliable and trustworthy scientific publication from the poorly-designed rushed work submitted all too often to pad the CV’s of the masses trying to climb the competitive academic career ladder. 

I personally reviewed much of the literature published on the merits of LLLT for tinnitus and most of the studies are small and published in journals with low impact factors (meaning they are less selective with regard to the research they publish and their peer review process may not be as critical). Several of the studies reported improvements in tinnitus that were statistically significant (if they manipulated the numbers favorably) but not really clinically significant. For instance, an average decrease in the Tinnitus Handicap Inventory of one point may be statistically significant in a study that has enough subjects, but it is not likely a change that most tinnitus sufferers would find meaningful in real life. Many of the studies on this subject lacked appropriate control groups and others measured the severity of tinnitus using tools with limited validity and reliability. 

So, in my personal review of the published literature on this subject, I could not find a single convincing well-designed randomized controlled trial supporting the use of LLLT for the treatment of tinnitus. This conclusion is consistent with a recently published systematic review and meta-analysis on this topic published by a Taiwanese research group (Chen CH, Huang CY, Chang CY, Cheng YF. Efficacy of Low-Level Laser Therapy for Tinnitus: A Systematic Review with Meta-Analysis and Trial Sequential Analysis. Brain Sci. 2020 Dec 2;10(12):931). Their search uncovered eleven randomized controlled trials related to the use of LLLT to treat tinnitus, including a total of 670 subjects. When all the data was compiled together and analyzed, they observed no significant benefit of LLLT in the treatment of bothersome tinnitus. 

Now, there are many therapeutic benefits of lasers, but there are limits to what this technology can achieve. I have two main doubts with regard to the potential of this technology ever being useful for tinnitus sufferers:

• First of all, it's widely accepted that the persistence of bothersome tinnitus is largely due to changes in the brain, so therapies that solely target the ears are not likely to provide benefit. 

• My second doubt is related to the physics of lasers in relation to the anatomy of the inner ear. The cochlea is contained within the petrous temporal bone, the hardest/densest bone in the human body. If we want to induce changes in the cochlea using a laser pointed in the ear canal, we would have to find a laser with enough power to penetrate into the petrous bone without damaging the other tissues along its path, like the eardrum and the middle ear bones. And if we can find a laser that accomplishes this goal, is that laser energy going to just stop in the cochlea or might it pass right through the petrous bone to the brainstem? If so, what kind of undesirable effects might that produce?

In conclusion, we at Alleviate do not recommend the use of low level laser therapy (LLLT) for the treatment of tinnitus and do not feel this is a strategy that is likely to ever be effective for this indication. The good news is that there are already clinically-proven strategies to improve tinnitus that are accessible and low risk. That's what the science-driven Alleviate Integrative Tinnitus Therapy program is all about. Come check out what we can do. Our program is changing lives on a daily basis. Be our next success story!

www.AlleviateTinnitusTherapy.com