The tympanic membrane is a three-layered structure (outer keratinized squamous epithelium, middle fibrous layer, inner mucosal layer) separating the external auditory canal from the middle ear cavity. The TM is essential for sound transmission to the ossicular chain and provides barrier function against middle ear infection. Perforation disrupts both functions, causing variable conductive hearing loss (depending on size and location) and predisposing to recurrent middle ear infections from external contamination. The TM has remarkable healing capacity: small acute perforations may heal within weeks, while larger or chronic perforations often require surgical intervention.
Etiology determines management approach. Acute otitis media with perforation is the most common cause, with perforation typically anterior or posterior-inferior, resulting from increased middle ear pressure causing rupture and pus drainage. Most heal spontaneously within 1-3 months. Traumatic perforation occurs from slap injury, blast injury, water sports, or direct penetrating trauma (cotton swabs); these typically heal spontaneously in 80-90% within 3 months. Iatrogenic perforation includes deliberate myringotomy with tube placement (most heal after tube extrusion) and accidental injury during ear examination or procedures. Chronic suppurative otitis media (CSOM) results in persistent perforation with recurrent or continuous drainage, often associated with cholesteatoma in dangerous types. Each etiology has distinct natural history, complications, and management requirements.
Clinical evaluation includes detailed otoscopic examination using operating microscope or oto-endoscope to assess perforation location (central versus marginal—marginal more concerning for cholesteatoma), size (small <25%, medium 25-50%, large >50%, total), edges (active versus chronic), middle ear status (mucosa appearance, fluid, polyps, cholesteatoma), and surrounding TM remnant. Pure tone audiometry quantifies conductive hearing loss (typically 5-30 dB) and identifies any sensorineural component. Tympanometry shows large volume measurement confirming perforation. Treatment depends on etiology and chronicity. Acute perforations: water precautions (avoid swimming, use ear plug or cotton with petroleum jelly during showering), avoidance of nose blowing, observation for spontaneous healing 1-3 months. Topical antibiotics if discharge present. Chronic perforations require surgical repair: myringoplasty (TM repair only, simpler procedure) or tympanoplasty (TM plus middle ear reconstruction including ossicular chain reconstruction if needed). Modern techniques use various grafts: temporalis fascia (most common), tragal or conchal cartilage and perichondrium, or fat (small perforations only). Underlay technique places graft beneath TM remnant; overlay technique replaces eroded squamous epithelium. Cartilage tympanoplasty has gained popularity for revision cases or recurrent perforations. Success rates 85-95% in primary cases. Cholesteatoma requires more extensive mastoidectomy with tympanoplasty.