Characterization of Corneal Involvement in Eyes With Mucous Membrane Pemphigoid by In Vivo Confocal Microscopy
To describe the morphological features of the corneal epithelial layers, subbasal nerve plexus, stroma, and endothelium in patients with mucous membrane pemphigoid (MMP) as shown by in vivo confocal microscopy (IVCM).Methods:
Central corneal images were captured from 10 healthy age-matched control eyes and 30 eyes with clinically diagnosed MMP by in vivo laser scanning confocal microscopy (HRT III RCM). Morphological changes of the corneal epithelial layers, stroma, and endothelium, characteristics of corneal nerves, and presence of inflammatory dendritic cells (DCs) were evaluated.Results:
Images obtained by IVCM from 40 eyes were analyzed. The eyes with MMP were divided into 2 groups based on clinical staging: 16 eyes with end-stage MMP and 14 eyes with non–end-stage MMP. Compared with controls, IVCM in eyes with end-stage MMP displayed severe conjunctivalization and neovascularization of the cornea, with otherwise limited identifiable cellular or structural elements. Those with non–end-stage MMP showed metaplasia of the corneal epithelial layers, presence of hyperreflective cells similar to conjunctival cells, intraepithelial defects, fibrosis of anterior stroma, and hyperreflective endothelial deposits. Images of the subbasal nerve plexus demonstrate significant reduction in density (1251.3 ± 806.9 μm/frame vs. 2688.8 ± 607.33 μm/frame, P < 0.001), increased tortuosity (2.76 ± 0.6 vs. 2.3 ± 0.42, not significant), decreased reflectivity (2.73 ± 0.4 vs. 3.46 ± 0.52, P < 0.01), and increased density of DCs (115 ± 88 cells/mm2 vs. 43.9 ± 28.14 cells/mm2, P < 0.05) in MMP-affected eyes compared with controls.Conclusions:
IVCM reveals profound and variable microstructural changes in the corneas of patients with MMP compared with normal controls. Our study demonstrated decreased corneal nerve density and elevated DC density in eyes with non–end-stage MMP compared with normal controls. Frequent scarring, conjunctivalization, and neovascularization observed in eyes with end-stage MMP preclude recognition by IVCM of the morphologic architecture of the corneal layers. Our findings suggest implications for using IVCM to evaluate and monitor patients with MMP.