Ngao, C.F., Tan, T.S., Narayanan, P. et al. Eur Arch Otorhinolaryngol (2014) 271: 975. doi:10.1007/s00405-013-2491-3
The aim of this study is to examine the effectiveness of transmeatal low-power laser stimulation (TLLS) in treating tinnitus. This is a prospective, double-blinded, randomized, placebo-controlled trial. Patients with persistent subjective tinnitus as their main symptom were recruited into the study from the outpatient clinics. The recruited patients were randomized into the experimental group or TLLS+ group (patients in this group were prescribed to use TLLS at 5 mW at 650 nM wavelength for 20 min daily and oral betahistine 24 mg twice per day for a total of 10 weeks) and the control group or TLLS− group (patients in this group were prescribed with a placebo device to use and oral betahistine 24 mg twice per day for 10 weeks). All patients were required to answer two sets of questionnaires: the Tinnitus handicap inventory (THI) and visual analogue scales (VAS) symptoms rating scales, before starting the treatment and at the end of the 10-week treatment period. The total score of the THI questionnaire was further graded into five grades, grade 1 being mild and grade 5 being catastrophic. Wilcoxon-signed ranks test and Mann–Whitney test were used to compare and analyze the THI and VAS scores before and after treatment for each group. Changes with p value of <0.05 were considered as statistically significant. Chi square test was used to analyze the change of parameters in categorical forms (to compare between TLLS+ and TLLS–). Changes with p value of <0.05 were considered as statistically significant. Forty-three patients successfully and diligently completed their treatment. It was noted that using any condition of the device, TLLS+ or TLLS−, patient’s tinnitus symptoms improved in terms of THI scores (TLLS+, p value = 0.038; TLLS−, p value = 0.001) or VAS scores with a change of at least one grade (TLLS+, p value = 0.007; TLLS−, p value = 0.002) at p value <0.05 significant level. In contrast when TLLS+ group was compared with TLLS− group, no statistically significant result was obtained. In term of VAS scores, there seems to be no statistically significant improvement in patients’ annoyance, sleep disruption, depression, concentration and tinnitus loudness and pitch heard between the two groups. Transmeatal low-power laser stimulation did not demonstrate significant efficacy as a therapeutic measure in treating tinnitus.