Therapeutic Response to Photobiomodulation in Home-Based and Outpatient Protocols for Vaginal Dysfunctions: A Randomized Clinical Trial

INTRODUCTION Vaginal dysfunctions represent a frequent problem in clinical practice, with high prevalence and a significant impact on women's quality of life and sexual health. Among the most common conditions are vulvovaginal candidiasis (VVC), bacterial vaginosis (BV), and genitourinary syndrome of menopause (GSM). It is estimated that approximately 75% of women will experience at least one episode of VVC during their lifetime, with 5% to 8% progressing to recurrent forms. BV affects approximately 23% to 29% of women of reproductive age, whereas GSM may affect up to 50% of postmenopausal women.

These conditions share alterations in vaginal homeostasis, including microbiome dysbiosis, local inflammation, and impairment of epithelial integrity, factors that are directly associated with the presence of symptoms such as vaginal discharge, pruritus, odor, vaginal dryness, and dyspareunia. Such manifestations have a substantial impact on sexual function, contributing to pain during sexual intercourse, reduced sexual desire, and impairment of interpersonal relationships. This impact is even more pronounced among women undergoing cancer treatment, particularly in cases of hormone-dependent neoplasms, in which the use of hormonal therapies is contraindicated. In these patients, GSM tends to be more severe and more difficult to manage, reinforcing the need for non-hormonal therapeutic alternatives.

In this context, photobiomodulation has been investigated as an innovative therapeutic approach capable of acting on multiple mechanisms involved in vaginal dysfunctions. Evidence demonstrates that this therapy promotes modulation of the inflammatory response, increased mitochondrial activity, stimulation of angiogenesis and collagen synthesis, in addition to immunomodulatory effects. Recent studies have reported clinical benefits of photobiomodulation in vulvovaginal conditions, including improvements in tissue trophism and associated symptoms.

Fungal and bacterial infections, such as vulvovaginal candidiasis and bacterial vaginosis, have shown increasing recurrence rates, making clinical management more complex and frequently associated with limited resolution of the clinical condition. Evidence suggests that photobiomodulation may act as an adjuvant therapy, contributing to the modulation of the local inflammatory response and the improvement of tissue conditions. In GSM, photobiomodulation has demonstrated the potential to improve vascularization, epithelial thickness, and vaginal elasticity, representing a particularly relevant alternative for women with contraindications to hormone therapy, such as those in the post-cancer treatment setting.

Despite these promising findings, gaps remain regarding the standardization of therapeutic protocols and the comparison between different modalities of photobiomodulation delivery, particularly between home-based and outpatient protocols. In light of this scenario, the present study aims to compare the therapeutic response to photobiomodulation administered through home-based and outpatient protocols in the treatment of genitourinary syndrome of menopause, bacterial vaginosis, and vulvovaginal candidiasis.