Early corneal findings in Cogan's syndrome.

We evaluated the ocular manifestations of Cogan's syndrome in 13 consecutive patients. The most frequent and earliest ocular finding was bilateral peripheral subepithelial keratitis consisting of faint, nummular lesions. The subepithelial keratitis was responsive to topical administration of corticosteroids. Peripheral subepithelial keratitis was seen in four patients and strongly suspected on review of history in three additional patients. Deep stromal keratitis was seen in two patients, while only one patient developed classic findings of Cogan's syndrome, ie. interstitial keratitis with vascularization. Additionally, five patients presented with noncorneal ocular inflammatory disease and deafness (atypical Cogan's syndrome). Early subepithelial keratitis in Cogan's syndrome may be mistakenly diagnosed as trival ocular inflammatory disease, and suppressed by topical corticosteroids, resulting in delayed diagnosis of Cogan's syndrome in the absence of classic corneal findings. Early diagnosis of Cogan's syndrome is important inasmuch as prompt treatment of cochlear symptoms with systemic corticosteroids may prevent or ameliorate deafness.