![]() ![]() Many patients with LCD will require surgical intervention for treating recurrent erosions and decreased vision. Other exam findings include fleck-like opacities, subepithelial white dots, and "ground-glass" stromal haze, which starts centrally and become more diffuse (2). As the disease progresses, they spread deeper and peripherally in the stroma with sparing of the limbus (1, 2). These lattice lines are initially found in the superficial central cornea. It is characterized by lattice lines which are linear, radially oriented, branching refractile opacities described as "glass like" located in the anterior stroma (See Figure 2A and 2B). It is typically an autosomal dominant, bilateral disease that typically presents toward the end of the first decade of life with symptoms of recurrent corneal erosions and decreased vision. Lattice corneal dystrophy (LCD) is the most common of the corneal epithelial-stromal dystrophies. Masson Trichrome stain demonstrating epithelial staining Reis-Bückler corneal dystrophy (click images for larger view)Ī: H&E of Reis Bückler showing destruction of Bowman's layer and irregularī. The hyaline-like material consists of rod-like bodies ultrastructurally, which helps distinguish it from Thiel-Behnke corneal dystrophy (1, 2).įigure 1. The deposits stain red with Masson trichrome stain (2). Histopathology reveals anterior stromal and subepithelial deposits of hyaline-like material which disrupt and often replace Bowman's layer (See Figure 1A and 1B). In more advanced stages of the disease, the opacities can extend to the limbus and deeper stroma (2). Irregular, grey-white, geographic-like opacities are located in the Bowman layer and anterior stroma. Reis-Bücklers, formerly known as Granular corneal dystrophy type III or Corneal Dystrophy of Bowman's type I, typically present with normal corneas at birth but develop painful recurrent erosions, opacification, and progressive vision loss within the first decade of life (1). The dystrophies typically have an autosomal dominant inheritance and involve Bowman layer and stroma (3). No effective treatments to prevent or attenuate the deposition of the keratoepithelin have been identified. To date, 63 different mutations have been identified in the TGFβI gene. Krachmer mapped granular type I, granular type II, and lattice dystrophy to chromosome 5q in 1994 (4). A group of researchers and clinicians including Edwin M. Interestingly, the TGFβI gene mutation was discovered in part at the University of Iowa. When a mutation in the TGFβI gene occurs, the keratoepithelin structure is abnormal and accumulation of the insoluble protein or its proteolytic fragments occurs in the cornea (1, 3). Being a small protein roughly the size of albumin, it has the capability to diffuse through the corneal stroma. This protein acts as an adhesion protein and is present in normal stroma. TGFβI is located on chromosome 5q31 and codes for keratoepithelin, a protein secreted by corneal epithelium. Congenital hereditary stromal dystrophyĮpithelial-stromal dystrophies are caused by mutations in transforming growth factor beta-induced (TGFβI) gene, also known as the BIGH3 gene.Old classification of corneal stromal dystrophies Lattice corneal dystrophy, type 1 and variants.Table 1: Epithelial-stromal Corneal Dystrophies ![]() The old classification for corneal stromal dystrophies is listed in Table 3. Table 1 and 2 list the epithelial-stromal dystrophies and stromal dystrophies (2). Most dystrophies previously considered stromal are now classified as either epithelial-stromal dystrophies or stromal dystrophies. The 2015 International Committee for Classification of Corneal Dystrophies (IC3D) classification system has divided corneal dystrophies into 4 categories: epithelial and subepithelial dystrophies, epithelial-stromal dystrophies, stromal dystrophies, and endothelial dystrophies. The disorders may or may not affect vision and may or may not be symmetrical (1). These deposits are not caused by inflammation, infection, or trauma, but by genetic mutations that lead to transcription of aberrant proteins resulting in the accumulation of insoluble material within the cornea. Corneal epithelial-stromal and stromal dystrophies are a group of inherited disorders of the cornea that are caused by progressive accumulation of deposits within the layers of the cornea. ![]()
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