The Effect of Light Therapy on Chronic Pain

Chronic pain is a major problem in the USA and the rest of the world, currently, all available pharmacological interventions carry with them significant side effects. Pain clinics are specially equipped to perform intentional pain procedures to manage pain. However, there remain groups of patients what neither benefit from pharmacological nor from interventional pain procedures. Other methods have shown only minor benefits such as hypnosis or cognitive behavioral therapy. Therefore, other techniques need to be investigated. Light therapy has been shown to have significant biological effects on humans. For example, light therapy is used to manage depression. Several clinical trials have shown that certain wavelengths of light can improve wound healing, decrease temporomandibular joint dysfunction (TMJ) pain, and decrease fear of back pain. In these trials, light was directed at the site of pain. In an attempt to better understand the effect of different wavelengths of light, pre-clinical studies were conducted using rats. The investigators have shown green and blue Light emitting diode, (LED) light produced antinociception (analgesia) and reversed neuropathic pain associated with several models of chronic pain. The analgesic effect of light was completely blocked when rats had their eyes covered, this suggests that the analgesic effects seen are mainly due to systemic effect through the visual system. Preliminary experiments on rats suggest that this effect is mediated through the endogenous opioids and cannabinoid system. The investigators believe that LED light is a safe alternative to pharmacological intervention to manage pain by stimulating the endogenous endorphin and cannabinoid systems. The investigators initial target participants with history of HIV, chemotherapy induced peripheral neuropathy and fibromyalgia. Participants will be divided into 2 groups. The first group will be a control group exposed to white LED light. The second group will be exposed to green LED light, respectively. Participants will be asked to take LED light home and will be asked to set in a dark room for 2 hours daily for 3 months with their LED light on. At the end of the 3 months trial, the investigator will assess their pain intensity, analgesic use, and overall quality of life. The investigators hypothesis is that participants exposed to green and blue light will have less use of analgesics and will have better life quality.

During the initial visit, the investigator will collect several pieces of data from participants that are considered part of the routine care, if you are being seen in the clinic, this information will also be used for research purposes. Initially the investigator will ask participants to provide their age, gender, work status, disability status, type of work, whether a previous pain physician has evaluated or provided treatment in the past, if there is any ongoing litigation, a detailed description of the pain (burning, electrical, shooting…etc.) and its location. If the participants are being seen in the clinic for their normal care a detailed physical examination assessing the motor strength of the upper extremities, sensation to light touch and reflexes that is part of the standard of care will be provided for the participants. The participants will be asked to give a numerical value for their pain (a scale from 0-10 where 0 is no pain and 10 is the worst pain imagined). Two questionnaires will be provided for the participants to complete which are not standard of care. The first one is the EuroQol Group (EQ-5D) which provide an over assessment of the quality of life. The second is a medication log to document their analgesics use. If the participants are being evaluated via telephone call, the same questions will be conducted, but no physical exam will be provided. The participants will be assigned to either a white, or green light group. The participants have 50% chance of being in either group. Once the participants are assigned a light group, the participants will be given a strip of Light emitting diode, (LED) light that correspond to their color group. The participants will be asked to take and use the LED strip in a dark room in their house every day for two hours to be exposed to the light, the participants will do this for 10 weeks. The study start date and the outcome assessment timeline will begin from the date of your first exposure to the assigned light. The participants will be asked to complete their weekly questionnaires and daily log, these will be given to the participants on their first clinic visit or sent to the participants if they live out of town. There will be several follow up appointments as detailed below. There is a chance the participants may be asked to cross over into a different group from the one the participants were assigned, there will we a 2 week washout period, then return to clinic for light assignment then light exposure for 10 week, similar visits as described below. For the follow up clinic visit or phone call (Week 10), data similar to the information gathered at the initial visit will be collected. The description of the pain (burning, electrical, shooting…etc.) and its location will be reviewed. A physical examination assessing for pain and sensation to light touch that is part of the standard of care will be provided for the participants. At the end of the study, the participants will be asked to return the LED strip, their logs and questionnaires. There is an optional blood draw and saliva sample collection for patients that consent to this. Blood and saliva samples will be collected at baseline and end of study, blood draws will be done to look for inflammatory mediators, increased anti inflammatory mediators and endocannabinoids. Saliva samples will be collected to check for melatonin.

Initially, patients will receive White LED exposure, then they will be crossed over to Green LED exposure. The patients will not be told which one is the treatment and which one is the control.

Subjects will exposed to white light provided to them, in their homes in a dark room for approximately 2 hours for 10 weeks

Subjects will exposed to green light provided to them, in their homes in a dark room for approximately 2 hours for 10 weeks.

Subject will be exposed to white light (sham) for 10 weeks, then have a wash out period for 2 weeks, then exposed to green light (experimental) for 10 weeks.

reduction in the intensity of fibromyalgia pain as measured by the Numerical Pain Scale (NPS). The NPS has a value ranging from 0 to 10 out of a maximum of 10. ) means no pain. 10 means the most severe pain.

Using the EQ-5D-5L (EuroQol five-dimension scale) assessment questionnaire, this questionnaire consists of five questions assessing the mobility, self care, ability to perform daily activity and overall functionality, pain discomfort, and anxiety are all scales that have 5 different answers to choose from consisting of one, to having no problems, to five being unable to. This will be a weekly questionnaire that will be assessed at the end of the study to check for improvements. Values of these assessments are scored, lower values are better.

VAS, which is a scale of 0 -100, 100 meaning the best health you can imagine and 0 means the worst health you can imagine. This will be a weekly questionnaire that will be assessed at the end of the study to check for improvements.

Evaluating the percentage change in the pain intensity using the provided survey. The scale ranges from 0-100%. This is a reported value by the patient which is subjective in nature.

Evaluating the percentage change in the pain episode frequency using the provided survey. The scale ranges from 0-100%. This is a reported value by the patient which is subjective in nature.

Evaluating the percentage change in the pain episode duration using the provided survey. The scale ranges from 0-100%. This is a reported value by the patient which is subjective in nature.

Evaluating the percentage change in the ability to fall asleep using the provided survey. The scale ranges from 0-100%. This is a reported value by the patient which is subjective in nature.

Evaluating the percentage change in the ability to stay asleep using the provided survey. The scale ranges from 0-100%. This is a reported value by the patient which is subjective in nature.

Evaluating the percentage change in the ability to work using the provided survey. The scale ranges from 0-100%. This is a reported value by the patient which is subjective in nature.

Evaluating the percentage change in the ability to excersize using the provided survey. The scale ranges from 0-100%. This is a reported value by the patient which is subjective in nature.

Evaluating the percentage change in the ability to do chores using the provided survey. The scale ranges from 0-100%. This is a reported value by the patient which is subjective in nature.

reduction in the perceived intensity of the headache phase of the migraine episodes. The scale ranges from 0-100%. This is a reported value by the patient which is subjective in nature.

Decrease in use of analgesics from baseline. Medications and doses of analgesics will be documented at baseline, during the study the subjects will document their daily analgesic usage, at the end of the study the analgesic usage will be compared to baseline usage.

A survey to analyze the different types of pain using different descriptive (burning, sharp, shooting,...etc). The value ranges from 0-3. 0 means no pain. 3 means severe pain.

A survey to evaluate the effects of Fibromyalgia. The scale ranges from 0-100. 0 means no impact. 100 means there is a severe negative impact secondary to fibromyalgia. The scale is subjective in nature

A survey to evaluate the impact of headache. The value ranges from 36-78 points. 36 indicates no impact from headache. 78 indicates worst possible impact from headache.

A survey to analyze the quality of sleep. The value range from 0-21. 0 means the best quality of sleep. 21 means the worst quality of asleep. The survey is subjective in nature.

A subjective survey designed to investigate the impact of voiding on people with interstitial cystitis. The value ranges from 0-21. 0 means no negative impact. 21 means the worst possible impact.

Inclusion Criteria: Adults ages 18 - 80 able to understand English and comply with study protocol Peripheral neuropathy from HIV or chemotherapy. History of fibromyalgia Headaches Chronic Pain 7-day average numeric pain score of 5/10 or greater at baseline evaluation Exclusion Criteria: Subjects receiving remuneration for their pain treatment Subjects that are incarcerated Subjects unable to read English and complete assessments Addictive behavior, severe clinical depression, or psychotic features

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