In vivo confocal microscopic evaluation of morphologic changes and dendritic cell distribution in pterygium.

PURPOSE

To observe morphologic changes and the distribution of dendritic cells in pterygium using in vivo laser scanning confocal microscopy (LSCM).

DESIGN

Prospective comparative study.

METHODS

Twenty-six eyes of 26 patients with pterygium and 17 eyes of 17 healthy subjects were recruited. Using LSCM, in vivo images of the pterygium and adjacent clear cornea were captured. The density of basal corneal epithelial cells and keratocytes in the anterior and posterior stroma and the density of dendritic cells in the pterygium and adjacent clear cornea were determined. In the controls, the central cornea and nasal bulbar conjunctiva were imaged. The density of basal corneal epithelial cells, keratocytes, and dendritic cells was evaluated.

RESULTS

Morphologic alterations of the sub-basal nerve plexus were observed in pterygium. The density of basal corneal epithelial cells and anterior keratocytes in pterygium was 5359.0 ± 543.1 cells/mm² and 407.4 ± 188.7 cells/mm² respectively, which was significantly lower than that in the controls (P < .001). The density of dendritic cells in the clear corneas of pterygia was 60.3 ± 25.5 cells/mm², which was significantly higher than the 23.6 ± 11.1 cells/mm² in the central corneas of controls (P < .001). The dendritic cell density in the pterygium was significantly higher than the density in the nasal bulbar conjunctiva of controls (P < .001).

CONCLUSIONS

Histopathologic alterations and increased dendritic cells were evident in pterygium and the adjacent clear cornea by in vivo LSCM. In vivo LSCM was found to be an effective method of observing the morphologic alterations of pterygium.