Abstract
Abstract: :
Purpose:To document for the first time development of fibrillary corneal lines secondary to Avellino corneal dystrophy. Methods:Observational case report. Results:A 70 year–old African–American female presented with bilateral superficial whitish granular deposits configured in vertically oblique radiating lines which emanated in the right eye from an elevated nodular point source located in the inferocentral cornea, and in the left eye from a concave boundary line again located in the inferocentral cornea. Corneal scraping of both eyes histologically revealed the presence of Mason's trichrome staining hyaline along with minute amounts of deeper material questionably staining positive with congo–red and demonstrating dichroism and birefrigence. DNA analysis of a peripheral blood sample revealed a mutation in codon 124 of the BIGH3 gene (Arg124His) consistent with Avellino corneal dystrophy. Conclusions:This phenotypically novel variant of Avellino corneal dystrophy assumed a superficial hyaline deposition pattern consistent with fibrillary lines. As originally described by A. J. Bron [BJO (1975) 59, 133–135], these lines have previously been limited to normal eyes, keratoconics, and contact lens wearers. They have been postulated to represent corneal nerve fibers distributed in vortex pattern by normal centripetal epithelial cell slide originating from the limbus. The demonstrated hyaline composition of the lines in this case coupled with their recent identification in neurotrophic corneas (ultra–structurally negative on biopsy for nerve fibers) lends further evidence to the hypothesis that fibrillary lines may in fact represent a variant of cornea verticillata, with the lines representing visualized junctional fronts of colliding epithelial cells as opposed to nerve fibers.
Keywords: cornea: epithelium • degenerations/dystrophies