Relationship of Size and Site of Tympanic Membrane Perforation with Conductive Hearing Loss

Abstract

Background: Tympanic membrane Perforation causes conductive hearing loss. TM perforation leads to reduction in ossicular coupling. According to the prevalent opinion, the degree of hearing loss in the context of tympanic membrane perforation changes with the change in the size of the perforation; larger perforation corresponds with greater hearing loss. Whereas, the effect of site of perforation on the hearing loss is still up for debate.

Objectives: The aim of this research is to study the relationship of size and site of TM perforation with the degree of hearing loss, and evaluate the effect of perforation involving the handle of malleus on HL.

Methods: A cross-sectional, prospective study carried out in the department of ENT-HNS Al-Mouwassat university hospital, Damascus university; from September 2020 to December 2021. The study included 76 patients who were evaluated in two stages, clinical and surgical. Images of the perforated ear were taken using an otoendoscope and be calculated by SketchAndCalc Area Calculator.

Results: 88 perforated ears were included in the study (M 14:F 62). Mean age were 29.26 Ys. Distribution of the perforations according to side were (36.8%) in the right ear, (47.4%) in the left and bilateral (15.8%). According to site of perforation, there were (Anterior 29.5%-Posterior 15.9%-Inferior 4.5%-Combined 50%). The greatest size of perforation was (81.28% of pars tensa) and the largest group of size was group C: 20-40% (52.3%). We found 34 (38.6%) malleolar perforation cases. Hearing loss analyse showing the maximum hearing loss degree (61.66 dB), minimum (15dB), greatest air-bone gap (45dB) and the low frequencies were the most affected.

Conclusion: We found a statistically significant difference in the degree of hearing loss and A-B gap according to the size of perforation and involving of the handle of malleus, but not with the site of the perforation.