Keratoconus associated with other corneal dystrophies.

OBJECTIVE: To report the concomitant presentation of keratoconus and corneal dystrophies at Wills Eye Hospital for the 10-year period from January 1, 1997, to December 31, 2006.
METHODS: Patients with concomitant keratoconus and corneal dystrophies were identified using a computer database. Complete ophthalmologic examination, keratometry, pachymetry, and computerized videokeratography were performed in all patients. When present, cornea guttata were confirmed by clinical examination and specular microscopy. Histopathologic examination with special stains of excised corneal buttons was performed.
RESULTS: Fifty-one patients manifested typical signs and topographic evidence of keratoconus associated with another corneal dystrophy. Fuchs dystrophy was the most common association accounting for 27 cases (52.9%), followed by anterior basement membrane dystrophy with 13 cases (25.5%) and posterior polymorphous dystrophy with 7 cases (13.8%). A bilateral combination of Fuchs dystrophy and anterior basement membrane dystrophy with keratoconus was seen in 3 cases (5.8%). Finally, there was 1 bilateral case (2%) of granular dystrophy. Histopathologic studies in cases that underwent penetrating keratoplasty confirmed the clinical diagnoses.
CONCLUSION: To our knowledge, this is the largest report of such a concurrence in the English literature and could lead to further studies on the possible pathophysiologic or genetic links between these entities, although a chance association cannot be excluded.