Keratoconus Associated With Corneal Granular Dystrophy in a Patient of Italian Origin

PURPOSE: To report a rare case of keratoconus concurrent with granular dystrophy in a patient of Italian origin. It is the seventh case in the literature and the second histopathologically documented case. METHODS: Keratoconus combined with granular dystrophy developed bilaterally in a 15-year-old boy from Italy. The corneal host button of the left eye obtained during penetrating keratoplasty 8 years later was analyzed histologically, immunohistochemically, and ultrastructurally. RESULTS: Histologic evaluation showed characteristic features of keratoconus, such as breaks in Bowman's layer and typical electron-dense trapezoidal deposits ultrastructurally. Other corneal dystrophies, such as Avellino dystrophy, were excluded. CONCLUSIONS: The concurrence of keratoconus and granular dystrophy raises the possibility of a genetic linkage of the diseases, although a chance association cannot be excluded. The diagnosis of keratoconus in patients with granular dystrophy is important because impairment of vision might be the result of keratoconus and could be treated with contact lenses instead of keratoplasty. In the future, the use of computerized corneal topography might help to detect more cases of keratoconus concurrent with granular dystrophy.