Sensorineural hearing loss and somatic insufficiency.

Studies of clinical, audiometric and histological defects in patients with conductive otosclerosis, demonstrated the occurrence of subclinical manifestations in the hair, nails, joints and teeth. Light-microscopic examination of the skin in these patients has shown metachromasia of the ground substance and degenerative abnormalities in the collagen and elastic fibres. Structural abnormalities, in the organs developing from the ectoderm and mesoderm, led to the conclusion that otosclerosis is a universal disease characterized by ectomesodermal insufficiency, a somatic insufficiency. Optical measurement of the corneal thickness by corneometry has been introduced as an objective method for the diagnosis of somatic insufficiency. This method, now used routinely in our clinic, shows a high frequency of abnormal corneal thickness among patients with otosclerosis. Such a person is termed 'cornea-positive'. Cochlear otosclerosis with pure sensorineural hearing loss has been studied by X-ray in axial and semiaxial tomography. These patients were often X-ray positive and among them there were many cornea-positive individuals. Cases with noise-induced hearing impairment may also be cornea-positive, i.e. they may exhibit, somatic insufficiency indicating that their hearing organs are characterized by a decreased resistance to noise. Corneometry has shown its value in the diagnosis of insufficient somatic constitution typical of individuals at risk.