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.