PURPOSE: To report the ultrastructure of superficial hypertrophic dendriform epitheliopathy (SHDE). METHOD: Two epithelial and two penetrating keratoplasty specimens from 1 patient were examined by electron microscopy. Tissue was processed for light and transmission microscopy. RESULTS: Striking intraepithelial aggregates corresponded to zones affected clinically. These stained heavily with toluidine blue and were composed ultrastructurally of electron-dense, microfibillar aggregates. The thin and degenerate epithelium contained a dense cytoplasm, lucent spaces, numerous microfilaments and glycogen granules. Basal cells showed infrequent hemidesmosomes. Basement membrane contained long-spacing collagen and Bowman's layer was replaced by a collagenous pannus, separated from the epithelium by large lucent spaces. Keratocytes within the pannus were degenerate, while collagen fibres were sparse and intermixed with microfilaments and long-spacing collagen. Large quantities of proteoglycans were present in pannus and stroma. Descemet's membrane was arranged in multiple lamellae containing basement membrane material, long-spacing collagen and microfilaments. CONCLUSIONS: SHDE is a distinct syndrome that occurs after keratoplasty in patients with tear dysfunction. It is speculate that it represents an aberrant form of keratinisation due to exposure and poor wetting in a denervated cornea. Chronic epithelial change leads to secondary reactive changes in the stroma.
PURPOSE: To report the ultrastructure of superficial hypertrophic dendriform epitheliopathy (SHDE). METHOD: Two epithelial and two penetrating keratoplasty specimens from 1 patient were examined by electron microscopy. Tissue was processed for light and transmission microscopy. RESULTS: Striking intraepithelial aggregates corresponded to zones affected clinically. These stained heavily with toluidine blue and were composed ultrastructurally of electron-dense, microfibillar aggregates. The thin and degenerate epithelium contained a dense cytoplasm, lucent spaces, numerous microfilaments and glycogen granules. Basal cells showed infrequent hemidesmosomes. Basement membrane contained long-spacing collagen and Bowman's layer was replaced by a collagenous pannus, separated from the epithelium by large lucent spaces. Keratocytes within the pannus were degenerate, while collagen fibres were sparse and intermixed with microfilaments and long-spacing collagen. Large quantities of proteoglycans were present in pannus and stroma. Descemet's membrane was arranged in multiple lamellae containing basement membrane material, long-spacing collagen and microfilaments. CONCLUSIONS: SHDE is a distinct syndrome that occurs after keratoplasty in patients with tear dysfunction. It is speculate that it represents an aberrant form of keratinisation due to exposure and poor wetting in a denervated cornea. Chronic epithelial change leads to secondary reactive changes in the stroma.