Correlation of Tympanic Membrane Perforation with Hearing Loss and Its Parameters in Chronic Otitis Media: An Analytical Study.

Chronic otitis media is one of the commonest illnesses in otorhinolaryngological practice which requires medical attention. Intact tympanic membrane acts as a shield for round window niche to create a phase difference in sound wave conduction. 700 patients of age 10-70 years with inactive mucosal chronic otitis media were included in the study. Condition of tympanic membrane and site of tympanic membrane perforation was noted and audiometric analysis was performed. 338 (48.28%) were males and 362 (51.71%) were females. In 1400 membranes examined, 769 (54.85%) presented with perforation. 631 (82.03%) had unilateral perforation and 69 (17.97%) had bilateral perforations. In unilateral cases, 289 (37.50%) had right ear perforation and 342 (44.53%) left ear perforation. Single quadrant perforations were present in 168 (21.74%) membranes and 419 (54.55%) involved two quadrants. Three quadrant perforations were seen in 62 (8.09%) and 120 (15.63%) perforations involved all four quadrants. In 171 (22.26%) ears, perforation was present anterior to handle of malleus and in 243 (31.53%) it was present only posterior to handle. In 355 (46.21%) perforations, handle of malleus was involved. Perforations involving posterior half of tympanic membranes showed greater loss than those involving anterior or inferior half of membrane statistically. Maximum loss (51.56 ± 5.1 dB) was seen in perforation involving all four quadrants. In 631 unilateral cases, conductive loss was seen in 424 (67.10%), 101 (16.10%) showed sensorineural and 74 (11.80%) showed mixed loss. Out of 769 perforated ears having hearing loss, 251 (37.69%) had complaints for 5-10 years with mean loss of 51.15 ± 7.8 dB, 172 (25.68%) had COM for 1-5 years with loss of 39.26 ± 5.1 dB. A mean hearing loss of 52.18 ± 4.2 dB was seen in 110 (16.52%) patients suffering from COM for more than 10 years. 134 (20.12%) patients having disease less than 1 year reported hearing loss of 36.46 ± 8.2 dB. The effects of perforation of tympanic membranes on transmission of sound and its dynamics are not easy to correlate because of additional pathological changes in middle ear.