Figure 6

Representative images of light microscopic examination of healed corneas with hematoxylin-eosin staining (A, B, E, F, I, J) and EGFR immunohistochemistry around the area of central cornea (C, G, K) and mid-peripheral cornea (D, H, L). The epithelial cell layer was densely packed, but the cells of the superficial layer were not flattened in group 1 (A). One case involving the epithelial layer of group 1 (B) was less compact than the other groups and showed some empty spaces (crucifix). The epithelial layers of group 2 and group 3 (E, F, I, J) were smooth and densely packed, and the superficial cells were flattened sufficiently. The immunohistochemical score of EGFR was 1+ (weak intensity membranous and cytoplasmic staining of nearly equal intensity) in group 1 (C, D). The score of EGFR was about 1+ to 2+ (moderate-to-strong intensity staining predominantly in the membranes) in group 2 (G, H). However, the intensity of EGFR staining in group 3 (K, L) was stronger than group 1 and group 2. Additionally, the intensity around the area of the mid-peripheral cornea (D, H, L) was stronger than that around the area of the central cornea (C, G, K). In group 3 in particular, the expression of EGFR was spread out nearly along the entire epithelial layer rather than the basal layer (L). Group 1: 8.0-mm BSS treatment and 8.0-mm epithelial removal (A, B, C, D), Group 2: 8.0-mm ethanol treatment and 8.0-mm epithelial removal (E, F, G, H), Group 3: 9.0-mm ethanol treatment and 8.0-mm epithelial removal (I, J, K, L); Scale bar – 50 μm.