Decreased Corneal Sensitivity and Abnormal Corneal Nerves in Fuchs Endothelial Dystrophy

Abstract

To determine corneal sensitivity and evaluate corneal nerves before and after keratoplasty for Fuchs endothelial dystrophy. Central corneal sensitivity, measured by using a Cochet-Bonnet esthesiometer in 69 eyes before and after different keratoplasty procedures for Fuchs dystrophy, was compared with that of 35 age-matched normal corneas. Corneal nerves were qualitatively examined by confocal microscopy in 42 eyes before and after Descemet stripping endothelial keratoplasty (DSEK). Corneal sensitivity in Fuchs dystrophy (4.61 ± 1.42 cm) was lower than that of age-matched controls (5.74 ± 0.48 cm, P < 0.001). Sensitivity decreased by 1 month after DSEK (2.98 ± 2.01 cm, P < 0.001), returned to preoperative sensitivity by 24 months (4.50 ± 1.63 cm, n = 33, P = 0.99), but remained lower than controls at 36 months (4.50 ± 1.48 cm, n = 15, P < 0.001). Sensitivity at 36 months after penetrating keratoplasty (1.46 ± 1.98 cm) remained decreased compared with preoperative sensitivity (P < 0.001). Subbasal nerves appeared sparse with abnormal branching before and through 36 months after DSEK. Sensitivity was lower in corneas without visible subbasal nerves by confocal microscopy at 12 months after DSEK (P < 0.005) than in corneas with visible nerves. Stromal nerves were frequently tortuous and formed loops in Fuchs dystrophy, and this appearance persisted in some eyes at 36 months after DSEK. Corneal sensitivity is decreased in Fuchs dystrophy compared with normal and remains subnormal even at 3 years after endothelial keratoplasty. Decreased sensitivity is likely to be related to loss of subbasal nerves and abnormal nerve morphology, which persist after endothelial keratoplasty.