Correlation between Degree of Hearing Loss and Intraoperative Findings in Tubotympanic Type of Chronic Suppurative Otitis Media

Abstract

Background: The aim of tympanoplasty done for tubotympanic type of chronic suppurative otitis media (CSOM) should not only be to achieve a dry ear, but also to give hearing improvement to the patient. Aim of this study was to determine the correlation between size and site of tympanic membrane perforation with degree of hearing loss and correlation between ossicular chain status and degree of hearing loss on pure tone audiometry. Methods: Patients with tubotympanic CSOM with hearing loss upto 60 dBHL undergoing tympanoplasty were examined to know the site and size of tympanic membrane(TM) perforation. Intraoperative findings pertaining to middle ear and ossicles were noted. Results: Out of 52 patients of tubotympanic type of CSOM, hearing loss was least (31.18±7.46 dBHL) in small perforations of the TM and highest in subtotal perforations (48.74±7.83 dBHL) which was statistically significant. Hearing loss was significantly more in posterior perforation (46.61±7.02 dBHL) than in anterior perforation of TM (32.65±8.77 dBHL). There was a statistically significant difference in pure tone average hearing loss between intact ossicle group (32.87±9.77 dBHL) and eroded ossicle group (43.39±9.60dBHL). Difference in air bone gap was also significant between intact ossicle group (24.09±9.56 dB) and eroded ossicle group (31.02±9.83 dB). Multiple ossicles were eroded in nineteen patients with incus being the most commonly eroded ossicle. Conclusions: In this study, hearing loss increased with increased size of TM perforation and also with posterior perforation. Incus was found to be the most commonly eroded ossicle. Multiple ossicles were seen eroded most commonly when hearing loss was moderate. The surgeon will be better equipped to do ossiculoplasty in view of these preoperative findings and also to counsel the patient better about their expectation of hearing improvement following surgery.