Abstract
Tinnitus and sudden sensorineural hearing loss (SSNHL) are prevalent otologic disorders that can severely affect quality of life. Low-level laser therapy (LLLT) and photobiomodulation (PBM) have been proposed as potential treatments aimed at enhancing cochlear microcirculation and cellular metabolism; however, their clinical efficacy remains uncertain. This systematic review evaluated the effectiveness of LLLT and PBM in improving tinnitus severity and hearing outcomes among patients with tinnitus and SSNHL. A comprehensive search was conducted in PubMed, Scopus, Web of Science, and the Cochrane Library from inception to September 2025. Eligible studies included randomized controlled trials, quasi-experimental designs, and pre-post studies in humans, published in English, that investigated LLLT or PBM for these conditions. Methodological quality was assessed using the Downs and Black 28-item checklist. Nine clinical studies met the inclusion criteria. Most demonstrated short-term reductions in tinnitus severity and handicap immediately following treatment, with several reporting superiority over placebo or control groups. However, these benefits often diminished after three to six months in longitudinal follow-ups. Audiometric improvements were mainly observed in participants with moderate hearing loss, whereas minimal changes occurred in severe cases. Across all studies, LLLT and PBM were reported to be safe and well-tolerated. Overall, LLLT and PBM appear to offer meaningful short-term relief of tinnitus symptoms and modest improvements in hearing thresholds for selected patients, although their long-term efficacy remains uncertain. Variability in treatment parameters and outcome measures underscores the need for standardized protocols and high-quality randomized trials to support evidence-based clinical recommendations.