Transcutaneous Electrical Nerve Stimulation for the Long-Term Treatment of Ocular Pain

Purpose Ocular pain is a debilitating condition that is challenging to treat as therapies that target the ocular surface are often ineffective. We previously reported a short-term reduction in ocular pain after one periocular transcutaneous electrical nerve stimulation (TENS) session. The current study aims to elucidate the long-term effect of TENS on ocular pain. Materials and Methods Fourteen individuals with eye pain were identified as candidates for a TENS device (RS Medical, Vancouver) for home use after a successful trial in clinic between February 2018 and July 2019 at the Miami Veterans Administration Hospital or University of Miami. Ten of the 14 patients were included in this retrospective review, based on the inclusion of receiving and using the device for a minimum of three months. The median age of the ten patients was 47.5 years, range 32-73 years, and eight were male. The main outcome measures were 1) frequency of long-term integration of TENS into ocular pain management and 2) patient reported ocular pain intensity (0-10) pre- vs. post-treatment. Results Patients reported an initial median use of the device 14.0 times per week and over time reducing the frequency to 3.0 times per week. All reported that the TENS unit was successfully incorporated into their ocular pain management routine for at least three months (median duration of use 6.5 months, range 3-14 months). Nine of ten patients reported subjective pain reduction with use of the TENS device at home. Overall, pain intensity decreased by approximately 27.4% (mean rank = 5.6, Z = -2.1, p = 0.02) post- vs. pre-treatment. No adverse events associated with TENS were reported in any patient. Conclusion Our preliminary data suggest that TENS can be integrated into the long-term management of ocular pain with improvements in overall pain intensity.