Fig. 1

Representative images of corneal epithelial layers in normal eyes and the eyes of patients with non-Sjögren’s dry eye (NSDE) and Sjögren’s syndrome dry eye (SSDE). Normal controls: (a) normal superficial epithelial layer with hyper-reflective cells in the process of desquamation, presenting visible large nuclei; (b) wing layer with regular shape cells, presenting bright cell borders and dark cytoplasm; (c) basal epithelial layer with smaller cells presenting heterogeneous cytoplasmic reflectivity. Dry eye patients: (d, e, f) and (g, h, i) superficial, wing and basal epithelial layers for NSDE and SSDE respectively, showing superficial epithelial squamous metaplasia (enlarged and hyper-reflective cells), patchy alterations with enlarged and irregular cells within the wing and basal epithelial layers, thus lower cell density as compared to normal controls