Chronic otitis media and sensorineural hearing loss: is there a clinically significant relation?

Previous investigations into the possible relation between chronic otitis media (COM) and sensorineural hearing loss (SNHL) have resulted in differing results and conclusions. A retrospective study was conducted to examine the relation between COM and SNHL, using strict selection criteria for cases so as to eliminate co-variables. In addition, various COM parameters were studied to determine if a correlation with the severity of the SNHL existed. At the University of Virginia, charts of all patients undergoing chronic ear surgery from September 1983 to March 1993 were reviewed. Sixty-nine patients met the following criteria: unilateral COM and no history of head trauma, meningitis, post-traumatic tympanic membrane perforation, labyrinthine fistula, or coexisting otologic condition of either ear. From these charts, audiograms were then analyzed for evidence of SNHL, defined as the difference in preoperative bone conduction thresholds between diseased and control (normal contralateral) ears. Mean bone conduction differences were small: -0.5 dB at 500 Hz, 0.9 dB at 1,000 Hz, 4.4 dB at 2,000 Hz, and 3.6 dB at 4,000 Hz. There were nonsignificant bone conduction threshold differences that trended toward greater SNHL with diseased mucosa and cholesteatoma at 2,000 and 4,000 Hz. There was no consistent correlation between severity of SNHL and presence of otorrhea, degree of ossicular erosion, or duration of disease. The authors conclude that COM may cause SNHL, but in the vast majority of patients this loss is not clinically significant.