Effectiveness of Intratympanic Steroid Injection on Hearing Threshold Improvement in Sudden Sensorineural Hearing Loss: A Meta-Analysis.

Abstract

Background and objectives: Sudden sensorineural hearing loss (SSNHL) is an otological emergency requiring early intervention to prevent permanent hearing impairment. Although recent studies have reported the effectiveness of intratympanic steroid injection (ITSI), evidence supporting its consistency across different clinical contexts remains limited. To evaluate the effectiveness of ITSI in improving hearing threshold(s) in patients diagnosed with SSNHL, and to examine whether treatment outcomes differ according to baseline hearing loss severity, clinical phenotype, and therapeutic role.

Materials and methods: A quantitative meta-analysis of 16 eligible studies was performed. Pooled effect sizes were calculated using a random-effects model, with treatment effects expressed as Hedges' g, and publication bias was assessed using Egger's regression test. Subgroup analyses were performed based on the severity of initial hearing loss, presence of clinical comorbidities, and therapeutic strategy (primary versus salvage therapy). Differences with p≤0.05 were considered to be statistically significant.

Results: ITSI significantly improved hearing thresholds, with a large pooled effect size (Hedges' g=-1.05; p<0.05). Egger's test indicated no significant publication bias (p=0.07). Subgroup analyses revealed no significant differences in treatment effectiveness between moderate-to-severe and severe baseline hearing loss (p=0.20), or among the various clinical phenotypes (p=0.63). However, ITSI demonstrated greater effectiveness when used as primary therapy (Hedges' g= -1.24) compared with salvage therapy (Hedges' g=-0.59).

Conclusions: ITSI was an effective intervention to improve hearing thresholds in patients with SSNHL. Treatment outcomes were not significantly influenced by baseline hearing loss severity or clinical phenotype, but were affected by the therapeutic role. Early use of ITSI as first-line therapy yielded the most optimal hearing recovery while remaining a valuable salvage option.