Dystrophia Smolandiensis - recurrent corneal erosions with a novel morphological picture

Purpose: The aim of this study was to describe morphological changes in a new corneal disease, Dystrophia Smolandiensis, characterized by recurrent corneal erosive episodes and formation of central corneal keloid-like opacities in approximately half of those affected. Methods: The corneas of seven affected individuals were examined using in-vivo confocal microscopy. Specimens of one primary corneal graft, one regraft, and one biopsied keloid-like region, obtained from members of a large family with the disease, were re-examined with a light microscope, and sections were stained with Congo red and immunohistochemically analyzed for fibronectin and S100A4. Results: Light microscopic examination revealed epithelial hyperplasia, absence of Bowman’s layer and subepithelial fibrosis. Fibronectin was expressed in the area of subepithelial fibrosis, and the keratocytes in this area generally expressed S100A4. The biopsy specimen stained positive for Congo red, suggesting an amyloid deposit. In-vivo confocal microscopy confirmed epithelial abnormalities, loss of Bowman’s layer, and significant alterations of the subbasal nerve plexus in affected individuals. Conclusion: The morphologic picture in Dystrophia Smolandiensis is novel for a condition dominated by recurrent corneal erosions at the clinical level. Although no single morphologic feature unique to the disease could be found, the general morphologic pattern of pathology (true keloid formation, an absence of Bowman’s layer, subepithelial fibrosis, and abnormal subbasal nerves) likely reflects a novel phenotypic expression of the healing response to recurrent erosion of the corneal epithelium. The pathogenesis of Dystrophia Smolandiensis, however, remains to be fully elucidated