Pilot Study of TENS for Ocular Pain

Approximately 20% of Veterans have a diagnosis of dry eye (DE) syndrome which is often accompanied by ocular pain that significantly impacts activities of daily living. Currently very few treatments are available for chronic ocular pain, likely because the mechanisms underlying this type of pain have only recently begun to be studied. New treatments that target the neuropathic mechanisms contributing to this type of pain are needed. The proposed research provides a crucial step in addressing the lack of treatments for neuropathic ocular pain by validating the methodology needed to support a randomized controlled trial of transcutaneous electrical nerve stimulation (TENS). TENS is a non-pharmacologic, non-addictive, non-invasive treatment that has been shown to be effective in other chronic pain conditions. The present pilot study aims to address the need for preliminary support of safety and efficacy of TENS for ocular pain, t to advance the study of new treatments for the long-term relief of chronic ocular pain and its impact on health.

Inclusion Criteria: * male or female * all races and ethnicities * at least 18 years of age * persistent eye pain for at least 6 months * average eye pain intensity of 4 or more on a 0-10 numerical rating scale * on a stable medication regimen for at least the past 3 months * naïve to TENS use for orofacial conditions * eye pain having neuropathic-like characteristics Exclusion Criteria: * presence of ocular diseases that are the likely cause of pain (i.e., corneal and conjunctival scarring, corneal edema, uveitis, iris transillumination defects, etc.) * contraindication to TENS (i.e., pacemaker, cardioverter defibrillator, neuro-stimulation (brain or spinal cord), bone growth stimulations, indwelling blood pressure monitors, epilepsy, pregnancy) * patients with confirmed signs of tear dysfunction * current participation in another study with an investigational drug or device within one month prior to screening