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

Abstract

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.

Figure 1

Representative photographs of the affected eyes with TSPK. In the left eye of patient #1, multiple coarse granular opacities stained with fluorescein are seen in the cornea.

Figure 2

Representative HRTII-RCM images of the basal cell layer of the corneal epithelium in three patients with TSPK. All images show the honeycomb-like appearance characteristic of the normal cornea. Highly refractive dots and aggregation of dendritic cells (arrow) were also evident in both eyes of patient #1, in the left eye (OS) of patient #2, and in the right eye (OD) of patient #3. Scale bar, 50 μm.

Figure 3

Representative HRTII-RCM images of the subepithelial nerve plexus of the cornea in three patients with TSPK. Aggregated dendritic cells were apparent in association with the nerve plexus (arrow) in both eyes of patient #1, in the left eye of patient #2, and in the right eye of patient #3. Scale bar, 50 μm.

Figure 4

Representative HRTII-RCM images of the right cornea of patient #3 before and after treatment. The dotlike opacities (arrow) and dendritic cells (arrow head) apparent in the basal cell layer of the corneal epithelium (BC) or in association with the subepithelial nerve plexus (NP) before treatment were no longer evident after treatment. Scale bar, 50 µm.