Morphology of corneal nerves and corneal sensation in dry eye:: a preliminary study

Purpose To evaluate the corneal sensitivity and nerve morphology in dry eyes. Methods A total of 32 eyes of 16 patients (10 Sjogren's syndrome and six non-Sjogren's syndrome) and 19 eyes of 10 age-matched controls were studied. Sensitivity of the central cornea was measured by the Cochet-Bonnet aesthesiometer. The morphology of corneal nerves was studied by in vivo confocal microscopy (ConfoScan 2.0, Fortune Technologies Srl, Vigonza (PD), Italy). Sub-basal epithelial nerve plexus, subepithelial nerve plexus, and stromal nerves were localized and evaluated for the number of nerves, thickness, reflectivity, and tortuosity for each frame. Results The mean corneal sensitivity of dry eye patients (5.6 mm/grs/S) was found significantly lower than that of the control (5.0 mm/grs/S) group (P < 0.01). Although the subepithelial nerves were thicker in dry eyes (mean: 6.38 +/- 1.18 mu m) than control eyes (mean: 5.72 +/- 1.27 mu m), this difference was not significant (P >= 0.05). Conclusion Decreased corneal sensitivity is not associated with morphological changes of corneal nerves in dry eyes.