The road to treatment 9
In January 2024, an article was published about a study into red light therapy in children with high myopia. For completeness, we have added the results of the study.
Low-level red light therapy (LLRL) has recently emerged as a treatment for myopia in children, with several studies reporting significant reductions in axial elongation and myopia progression. The purpose of this study was to characterize the output and determine the thermal and photochemical maximum permissible exposure (MPE) of LLRL devices for the control of myopia. For both LLRL devices evaluated here, LLRL devices approached or exceeded 3 minutes of continuous viewing the maximum tolerable error, which put the retina at risk of photochemical and thermal damage. Clinicians should be cautious about using LLRL therapy for myopia in children until safety standards can be confirmed.
More information can be found on both of these websites: University of Houston article about dangers of red light therapy en Red light instruments for myopia exceed safety limits
Red light therapy
At the beginning of 2022, several companies started offering red light glasses https://eye-power.co.uk en www.eyecharger.com.au, which may reduce vision loss in aging eyes, by affecting mitochondria. Since ADOA is a mitochondrial disease, we were naturally curious to see if it is safe for ADOA patients and could potentially benefit from it. ADOA is caused by a damaged gene (OPA1) that causes multiple problems in the mitochondria in so-called retinal ganglion cells, the cells that transmit information between the eyes and the brain. Mitochondria are primarily responsible for energy production by making a substance called ATP. ATP is produced in the mitochondrial membrane, where the OPA1 gene plays a role in several processes. If there is not enough ATP, the mitochondria are damaged. Damaged mitochondria release a substance that triggers cell death that leads to vision loss.
To understand how this device works, we contacted Professor Glen Jeffery of University College London, who has spent decades researching the mechanism in the eyes in relation to red light. He was kind enough to share his thoughts with us.
Can you describe in layman's terms how the approach works?
When mitochondria are challenged by age or disease, they have a reduced membrane potential - they have a charge, like a battery, and it decreases. When this happens, mitochondria produce less ATP, which is necessary for cell function. When the amount of ATP decreases significantly, channels in the mitochondrial membrane can eventually open and cause cell death. The pumps that produce ATP run in a relatively sticky layer of water molecules. Most experts believe that the absorption of long wavelengths by the water molecules reduces the stickiness and makes the running pump permanently faster. A faster running pump in turn increases ATP production. While scientists aren't entirely sure, this is currently the most likely mechanism. This is because the wavelengths that improve mitochondrial function partly overlap with the wavelengths that are absorbed by water. So when exposed to red light, ATP is increased, mitochondria continue to function, and cell death is avoided.
A question about the safety of the new red light goggles. There are usually extensive studies available on the safety of such new therapies, but at this time I am not aware of any such studies (the company claims it has been approved by the ethics committees of Moorfield's and UCL, and is not being commercialized marketed as a therapy, only as an anti-aging agent). Are there biological mechanisms that indicate that red light therapy is not safe, in adults and/or in children?
Safety of light generating devices depends on energy and wavelength. In general, longer wavelength devices are much safer at the same energy than short wavelength devices. I don't have a commercial relationship with the two companies (Eye-power and Eyecharger), but I tested their prototypes because it was important to me that there was something I knew was safe. Both products operate at energies and wavelengths for which I have received ethical approval from Moorfields Eye Hospital and also from University College London. This confirmed that they are well within safe range. However, they do not have a clinical safety seal. Obtaining this can be a lengthy process. I have told both companies that we would strongly disapprove of any attempt to claim that their devices are officially clinically approved, and I support this.
Having said this, in about 8 years of working in this field, I have not encountered any ill effects from using long wavelength light at an appropriate energy level. Researchers in this field have discussed this issue many times and this topic has been covered many times. No one identified a problem. We know there are situations where it just doesn't work, eg if administered at the wrong time of day or if the exposure is too long (>1 hour).
Can red light therapy restore lost vision by making the remaining retinal ganglion cells (RGCs) “work harder”, or can red light therapy stop the gradual vision loss typical of ADOA?
When it comes to ADOA specifically, there are many unknowns, but we can deduce the following. Based on mouse models (mice with modified OPA1 genes), there are potential benefits, but this has not been confirmed in human ADOA patients.
A conservative view would be that red light therapy can reduce the progression of the disease. We know it slows cell death and I've seen this in many situations. Can it fix anything? Well, not if the cell has died, but if the cell is inactive prior to cell death, then maybe it is. It certainly restores the function of the human cones in the eye that play a role in color vision. These cells do not die with age, but they gradually lose their function.
As far as I know, your research has focused on photoreceptor cells, which are not in the disease pathway of ADOA. Do you think that red light therapy could benefit elderly ADOA patients (whose vision is declining not only because of the decreasing number of RGCs, but also because the photoreceptor cells work less), even if nothing changes within the RGCs themselves?
So can it help ADOA? My response is that this can be done and with the right devices it can't hurt. So the worst case is that once or twice a week you waste 3 minutes of your time exposing your eyes. The more hopeful scenario is that the rate of the disease slows down when measured over a long enough period of time. Photoreceptor function will improve in the elderly, although not everyone observes it in everyday life. I've certainly seen some interesting results with red light and mitochondrial disease in a few kids whose parents have chosen to use red light therapy and keep me posted. But this is anecdotal. The bottom line would I use it for myself or my kids if necessary, yes I would.
Email interview with Glen Jeffery, by Peter Makai
As a final note from the Cure ADOA Foundation: We strive to keep you informed of research developments, we do not recommend specific treatments at this time. The only treatments that have been confirmed to be safe are those that your doctor (eventually) prescribes. Everything else is at your own risk.
