Let this be lattice? Dendritiform erosion in lattice dystrophy type I, a source of confusion.

Abstract

Lattice dystrophy type I is an autosomal dominant corneal dystrophy, which appears in the first decade of life [1, 2, 4]. Corneal involvement in lattice dystrophy type I is usually bilateral and symmetric. In the early stages, the lesions can appear as irregular, thin branching refractile lines and/or whitish, ovoid dots in the anterior axial stroma with clear intervening stroma. The lines start centrally and increase in size and number with time. They extend to the periphery and involve both the deeper and the superficial stromal tissue. The typical lattice filaments are radially oriented and branch dichotomously near their central terminations. As they overlap one another at various stromal levels, they create the typical lattice pattern. Indirect or retroillumination shows the lattice lines as refractile filaments with a double contour and a clear core. Refractile, glassy, homogeneous, discrete dots or more irregular opacities are seen with the filaments. With time, the opacities coalesce, and a diffuse groundglass haze may develop in the anterior and mid-stroma [1, 2, 4]. The predominant anterior involvement of this dystrophy commonly leads to recurrent erosions and irregularity of the epithelial surface, with accompanying visual disturbances [1, 2, 4]. Lattice dystrophy type I is a primary, localized corneal amyloidosis. Histologically, the epithelium is of variable thickness, with degeneration of the basal epithelium. The basement membrane is thickened and continuous but without normal hemidesmosomes. A variably thick, eosinophilic layer separating the epithelial basement membrane from Bowman’s layer is present and is composed of amyloid and collagen. Bowman’s membrane may be thicker or thinner than normal and is frequently fragmented in its periphery. The stroma contains large irregular deposits that distort the normal configuration of the corneal lamellae. There is a decrease in the number of keratocytes. Descement’s membrane and the endothelium are usually normal [1, 2, 4]. V. Vanlerberghe (&) S. De Craene Ph. Kestelyn Ghent University Hospital, Ghent, Belgium e-mail: vanlerbergheveerle@gmail.com