Intratympanic glucocorticosteroid therapy for idiopathic sudden hearing loss: Meta-analysis of randomized controlled trials

Background and objective: Glucocorticoids are the standard treatment for idiopathic sudden sensorineural hearing loss (ISSNHL), but whether intratympanic or systemic therapy is superior remains controversial. Previous meta-analyses of this question have omitted key clinical trials or included observational studies. Methods: English-language randomized controlled trials in OvidSP, PubMed, Embase, CINAHL, and the Cochrane Library comparing intratympanic versus systemic glucocorticoid therapy for ISSNHL were meta-analyzed using RevMan 5.3. The primary outcome of interest was improvement in pure tone average (PTA) threshold. Results: Six trials involving 248 patients receiving intratympanic steroids and 236 receiving systemic steroids were meta-analyzed. PTA thresholds were similar between the 2 groups at 3 months after therapy initiation (mean difference, 0.24; 95% confidence interval [CI] -2.43 to 2.91, P = .86; I² = 54%, P = .07, random-effects model). PTA thresholds were also similar at 6 months (mean difference, 4.69, 95% CI -5.84 to 15.22, P = .38), although the results showed extremely high heterogeneity (I² = 98%). Sensitivity analysis indicated that a single trial containing 250 patients provided the strongest evidence for equivalence between the 2 types of therapy. Rates of recovery within 3 months (defined as PTA improvement >10 dB) were similar between the 2 types of therapy (odds ratio 0.92, 95% CI 0.59-1.43, P = .70), with no significant heterogeneity in the pooled data (I² = 1%, P = .40). Conclusion: Intratympanic and systemic steroids' therapies appear to show similar short-term efficacy for restoring hearing in patients with ISSNHL. Intratympanic therapy may reduce systemic side effects associated with steroid use.