Bengal Journal of Otolaryngology and Head Neck Surgery (Jun 2013)
Evaluation of Cochlear Function in safe type of Chronic Otitis Media
Abstract
Abstract Objective of this article is to evaluate the correlation between the patients of safe types of chronic otitis media (COM) with their cochlear function of sensorineural hearing loss (SNHL). Total 600 cases of COM (safe type) in the age group of 13 to 49 years were evaluated and divided into two groups- active and inactive. Besides the routine investigations, special emphasis was given on pure tone audiometry (PTA) with a particular attention to bone conduction threshold. Out of 600 cases 94 patients (15.6%) showed SNHL. Our criterion of SNHL is "bone conduction loss of 25dB or more at any one or more of the frequencies of 250 to 4000Hz." The severity of hearing loss is increased with increase in duration of disease as well as size of perforation. Among the active cases that showed SNHL, PTA was repeated after three months so as to evaluate whether cochlear hearing loss was temporary or permanent. Both the mean air and bone conduction thresholds of diseased ears were significantly raised as compared to normal ears. SNHL caused by COM usually permanent, though some patients also had a reversible component in bone conduction. So it was concluded that the safeness of safe type of COM is questionable from hearing point of view. Hence this study was conducted to determine the severity of the condition and also to add one more in the review of literature. Keywords: Cochlear function, sensorineural hearing loss, chronic otitis media.
