Corneal features in ocular graft-versus-host disease by in vivo confocal microscopy

The purpose of our study was to determine the morphological features of the corneal epithelial layers, sub-basal nerve plexus and anterior stroma in patients with ocular graft-versus-host disease (oGVHD) compared to non-GVHD dry eyes and normal controls, using in vivo confocal microscopy (IVCM).

IVCM was used to capture central cornea images from eight volunteers with normal healthy eyes, ten patients with non-GVHD dry eye syndrome (DES) and 15 patients with clinically diagnosed oGVHD, in a cross-sectional study. Morphological changes of the corneal epithelial layers and anterior stroma, characteristics of corneal nerves and presence of dendritic cells (DCs) were then evaluated.

IVCM images obtained from 66 eyes were analyzed. The density of superficial epithelial cells was 636.07 ± 101.05 cells/mm² in the oGVHD group, 827 ± 99.62 cells/mm² in the DES group and 1277.2 ± 121.42 cells/mm² in the control group (P < 0.001). The density of wing cells was 4499.79 ± 976.36 cells/mm² in the oGVHD group, 4662.85 ± 319.72 cells/mm² in DES group and 6556.38 ± 503.99 cells/mm² in the control group (p < 0.001). The density of basal cells was 7850.93 ± 723.51 cells/mm² in the oGVHD group, 8570 ± 913.32 cells/mm² in DES group and 9759.8 ± 251.99 cells/mm² in the control group (p < 0.01). The density of nerve fibers was 11.22 ± 5.46 mm/mm² in the oGVHD group, 14.50 ± 4.27 mm/mm² in DES group and 19.56 ± 4.75 mm/mm² in the control group (p < 0.01). The DC density was 67.88 ± 71.82 cells/mm² in the oGVHD group, 40.06 ± 31.95 cells/mm² in the DES group and 29.45 ± 8.1 cells/mm² in the control group (P > 0.05). Visible networks of activated keratocytes were seen in the anterior stroma of eyes with oGVHD and DES, but not in normal controls.

IVCM revealed distinct microstructural changes in the corneas of patients with oGVHD and DES, similar between the two groups. Our findings suggest implications for use of IVCM to evaluate and monitor patients with dry eyes associated or not with GVHD.