In vivo observation of Langerhans cells by laser confocal microscopy in Thygeson's superficial punctate keratitis

PURPOSE To characterize the cornea of individuals with Thygeson's superficial punctate keratitis (TSPK) at the cellular level by laser confocal biomicroscopy. METHODS Both corneas of three patients with TSPK referred to Yamaguchi University Hospital were imaged with a laser confocal biomicroscope. Morphological changes were evaluated for each layer of the cornea. RESULTS The number of Langerhans cells was greatly increased in the basal cell layer of the focal corneal epithelium and in Bowman's layer in the four eyes affected by TSPK. Aggregates of these cells were associated with the subepithelial nerve plexus. Langerhans cells were also evident in the unaffected eyes of the two patients with unilateral TSPK, although their numbers were much smaller than those in the affected eyes. Topical treatment with betamethasone phosphate resulted in the virtual disappearance of Langerhans cells from the affected eyes. CONCLUSION The prominent association of Langerhans cells with TSPK suggests that the activation of these cells by inflammatory conditions might contribute to the pathogenesis of this disorder.