Cogan’s syndrome is defined as nonsyphilitic interstitial keratitis (an inflammation of the eye) and bilateral audiovestibular deficits (hearing problems and dizziness). It is more common in Caucasians than in other races. Onset of the disease is generally a brief episode of inflammatory eye disease, most commonly interstitial keratitis. This eye condition causes pain, lacrimation (tearing of the eye) and photophobia (eye pain with exposure to light). Shortly following these ocular (eye) symptoms, patients develop bilateral audiovestibular (ear) symptoms, including hearing loss, vertigo (dizziness) and tinnitus (ringing in the ears). Approximately half of patients ultimately develop complete hearing loss, but only a minority experience permanent visual loss. Other symptoms that may occur include headache, fever, arthralgia (joint pain), and systemic vasculitis (inflammation of the blood vessels). The symptoms typically deteriorate progressively within days. It is currently thought that Cogan’s syndrome is an autoimmune disease. The inflammation in the eye and ear are due to the patient’s own immune system producing antibodies that attack the inner ear and eye tissue.