Mixed Hearing Loss in Iatrogenic Tympanic Membrane Perforations over the Round Window Niche and the Immediate Effect of Paper Patch Myringoplasty

Objectives: Report the immediate audiologic effect of paper patch myringoplasty to repair iatrogenic tympanic membrane perforations directly over the round window.

Methods: Retrospective case-control study of 15 patients treated for inner ear disease with a MicroWick and dexamethasone for 1 month, resulting in 2-mm perforations over the round window. Paper patch myringoplasties were performed to repair the perforations. Audiograms were performed before and immediately after the paper patch myringoplasty.

Results: After paper patch placement, there was a significant improvement in air-bone gap at 250 (p < 0.001), 500 (p = 0.003), and 1000 Hz (p = 0.004) and a significant improvement in bone conduction (BC) threshold at 250 (p = 0.002), 500 (p < 0.001), 1000 (p = 0.002), 2000 (p = 0.003), and 3000 Hz (p = 0.02).

Conclusions: Paper patch myringoplasty improves both air conduction and BC hearing from small perforations over the round window. The decrease in BC hearing is a result of middle ear mechanics and is not a true sensorineural hearing loss.