Corneal changes in xeroderma pigmentosum: a clinicopathologic report.

PURPOSE: To report the clinicopathologic features of corneal involvement in patients with xeroderma pigmentosum.

DESIGN: Retrospective review of corneal histopathology.

METHODS: Thirteen corneal specimens of 11 patients with xeroderma pigmentosum who underwent keratoplasty (lamellar/full-thickness) for corneal involvement were studied. Five-micrometer-thick sections were made from all the samples and stained using hematoxylin-eosin and periodic acid-Schiff stains. A light microscopic examination was performed to study the histopathologic changes.

RESULTS: The corneal findings on clinical examination were haze, scarring, vascularization, stromal edema, pigment clumps on endothelial surface, and corneal thinning. The histopathologic evaluation revealed changes in all layers of cornea. Epithelial changes seen were intraepithelial edema, fibrosis, epithelial downgrowths, and pannus formation. The Bowman membrane was fragmented or absent. Stroma was characterized by alteration in the lamellar pattern, scarring, edema, loss of keratocytic nuclei, and calcification. The Descemet membrane was thickened to a variable extent in most specimens and there was marked loss of endothelial cells in all.

CONCLUSION: Most histologic features are consistent with the previous few reports. The remarkable finding in all corneal specimens was a moderate to severe degree of loss of the endothelial cells. This noteworthy finding supports the ultraviolet (UV) radiation-induced endothelial cell damage in these patients. This has an important clinical implication when planning for anterior lamellar keratoplasty, as endothelial cell density may be subnormal in these patients.