A comparative study on photobiological effects of low-level laser therapy and tinnitus retraining therapy in patients with acoustic trauma-induced tinnitus

Background and Aim: Tinnitus is a subjective auditory symptom referred to the perception of sound in the absence of external stimuli, and there is no definite treatment for it. Rehabilitation methods and laser therapy have been recommen­ded used for its management. This study aimed to investigate the photobiological effects of low-level laser therapy (LLLT) and tinnitus retraining therapy (TRT) in patients with acoustic trauma-induced tinnitus. Methods: This clinical trial was conducted on 60 patients suffering from acoustic trauma-induced tinnitus for more than six months, divided into three groups of LLLT, TRT and LLLT + TRT. The Persian version of tinnitus handicap inven­tory (P-THI), visual analog scale (VAS), and loudness match (LM) scale were used to collect data. The collected data were analyzed in SPSS version.22 software. The effect of time, group and time × group on the scores of VAS, LM, P-THI and its subscales were examined. Results: There was a statistically significant diff­erence between LLLT + TRT and LLLT groups after intervention in terms of LM (p = 0.002) and VAS (p = 0.001) variables, but no statistical sig­nificance for P-THI and its subscales (p = 0.442) was found. Conclusion: Combination of LLLT and TRT, as a therapeutic protocol, is recommended due to their remarkable effects in reducing acoustic trauma-induced tinnitus symptoms. The use of LLLT method alone, however, is not recommen­ded due to its lower effects. Keywords: Tinnitus; low-level laser therapy; tinnitus retraining therapy; tinnitus handicap inventory; loudness matching; visual analog scale