Photobiomodulation therapy for the treatment of vulvar pain among those with provoked vestibulodynia: a randomized controlled trial.

Abstract

Background: Provoked vestibulodynia (PVD) is characterized by recurring pain confined to the vulvar vestibule; histological studies show inflammatory mediators and neural proliferation in the vulvar tissues.

Objective: To determine whether a 15-session photobiomodulation (PBM) intervention is more effective than sham-PBM for reducing vulvar pain. Secondary objectives were to evaluate the effect of the PBM intervention on broader domains of vulvar pain, psychological outcomes, sexual function, perceived improvement and satisfaction, as well as to describe adverse events and adherence.

Design: Randomized controlled trial.

Participants: Participants with PVD were recruited from the local community.

Allocation: Randomized allocation to real- or sham-PBM (1:1) was concealed from participants and all members of the research team until after data analysis was complete.

Outcomes: Primary outcomes: pressure pain threshold (PPT), pain reported on the tampon test, and vulvar pain sensitivity reported on the Vulvar Pain Assessment Questionnaire (VPAQ). Secondary outcomes: pain-related domains reported on the VPAQ, sexual function, depression, anxiety and stress, pain catastrophizing, central sensitization to pain, Patient Global Perception of Improvement (PGPI), Perceived overall percent improvement (P%I), perceived satisfaction with treatment (%), adherence and adverse events. The primary end point was one week following the last PBM intervention session.

Intervention: Fifteen sessions of a real- or sham-PBM intervention were delivered over an 8-week period, progressing through five stages of incremental exposure to light in the red and near-infrared spectra applied to the vulvar vestibule, the perineum, and the sacral region.

Results: Thirty participants (16 real-PBM, 14 sham-PBM) enrolled and received their intended intervention; one (sham-PBM) was lost to follow-up. Vulvar pain was reduced more in the real- compared to the sham-PBM group; between group differences were 28.2-112.0 g/cm2 (d = 0.61) for PPT, 0.1-2.5 1(d = 0.60) for pain reported on the tampon test, and 0.1-0.9 (d = 0.87) for pain sensations reported on the VPAQ. Changes in other pain-related domains reported on the VPAQ, psychological outcomes and sexual function were not different between the real- and sham-PBM groups. Adherence to the intervention was nearly 100% among those who completed the study. Most participants in both groups were satisfied or very satisfied with the intervention (real-PBM = 80%; sham-PBM = 64%), with no group differences in satisfaction or perception of improvement.

Conclusions: The PBM intervention resulted in greater reductions in vulvar pain than the sham intervention. However, patients did not perceive that the real-PBM was significantly better than the sham-PBM intervention, and the intervention did not impact psychological outcomes or sexual function. ClinicalTrials.gov  Identifier: NCT04234542.