An In Vivo Confocal Microscopy and Impression Cytology Evaluation of Pterygium Activity

Abstract

To correlate pterygium activity with in vivo confocal microscopy (IVCM) and ex vivo impression cytology (IC) analyses. Twenty-eight pterygia from 16 patients were analyzed in this study. A pterygium activity score was obtained by summing four scores of ocular discomfort, pterygium hyperemia, keratitis, and the presence of Fuchs patches. Patients underwent pterygium IVCM analysis and collection of IC specimens on the pterygium. IC specimens were analyzed quantitatively by immunohistochemistry for goblet cell and dendritiform inflammatory cell density. IVCM images and IC results were compared to search for a possible correlation with the pterygium activity score. The presence of inflammatory cells, numerous blood vessels, and an irregular limit between the cornea and the pterygium with infiltration of hyperreflective cells in the adjacent corneal epithelium were the signs observed with IVCM associated with pterygium activity. Using IC, the density of goblet cells and dendritiform inflammatory cells was significantly correlated to the pterygium activity score (Spearman coefficient 0.765, P < 0.0001 and 0.799, P < 0.0001, respectively). In the same pterygium, dendritic inflammatory cell density and goblet cell density were also significantly correlated (Spearman coefficient 0.952; P < 0.0001). The correlation of pterygium cell changes with pterygium activity supports the role of inflammation and its relationship with goblet cells in the pathogenesis of pterygium.