Functional Correlations of Tympanic Membrane Perforation Size

Objective The correlation between tympanic membrane perforations and hearing loss was studied. Study Design Prospective data from 220 patients, who underwent primary surgery for simple chronic otitis media with a perforated eardrum, were analyzed. Setting Tertiary referral center. Patients One hundred fifty-one patients with 155 eardrum perforations, which were checked for correct diagnosis, normal middle-ear status, and integrity of the ossicular chain, were included. Interventions All patients underwent primary myringoplasty. Main Outcome Measures Preoperative conductive hearing loss due to eardrum perforations. Results Hearing loss shows a linear relationship with increasing eardrum perforation size. Umbo involvement shows a worsening of the hearing by 5 to 6 dB (p < 0.0001). The least impact of a perforation is seen at the resonance frequency of 2 kHz. Above and below 2 kHz, an "inverted V shape" of the air-bone gap is a consistent finding. If the air-bone gap exceeds the "inverted V-shape" pattern, additional pathology behind the eardrum must be assumed and addressed. Conclusion We propose using standardized photographs or drawings to document preoperative perforation sizes. A linear relationship between the size of a perforation and the conductive hearing loss does exist. Umbo involvement at the perforation margin may worsen the hearing by 5 to 6 dB, whereas the position of the perforation itself does not play a role. The least impact of a perforation is seen at the resonance frequency of 2 kHz. An "inverted V-shape" pattern, above and below 2 kHz, of the air-bone gap is a consistent finding. If the air-bone gap exceeds this pattern, additional pathology behind the eardrum perforation must be assumed and addressed.