In vivo confocal laser scanning microscopy of the cornea in dry eye

Abstract

We carried out an investigation into the morphological and quantitative corneal properties in dry eye with various underlying pathologies. Ten patients with aqueous tear deficiency, 8 with dysthyroid ophthalmopathy, 8 with chronic lagophthalmos and 10 normal participants were examined. Confocal microscope images were taken at the centre and at the lower and upper periphery of the cornea. Quantitative and morphological assessments of the epithelium, of the sub-basal nerves, of the stroma and the endothelium were made. The epithelial and corneal thicknesses were measured. The mean superficial and intermediate epithelial cell densities in the central cornea in the patient groups were significantly lower than in normal participants (p<0.01). The peripheral epithelial thickness was smaller (p<0.01); it was smallest in the lagophthalmos group. The cornea was thinner in the patient groups (p<0.01). For sub-basal nerves, the density had decreased (p<0.05), and in lagophthalmos the number of beadlike formations had increased (p<0.001); in some patients we found irregular branching patterns. Dry eye patients showed significant alterations in the cornea, presumably due to increased desquamation of the superficial cell layer. This was most pronounced at the lower periphery of the cornea in patients with exposure keratopathy.