Tear menisci and corneal subbasal nerve density in patients after laser in situ keratomileusis.

Abstract

To investigate the relationship between tear menisci and corneal nerve density in patients after laser in situ keratomileusis (LASIK). Twenty-eight eyes of 14 myopic patients were enrolled. Height and area of the upper and lower tear menisci--upper tear meniscus height, upper tear meniscus area, lower tear meniscus height (LTMH), and lower tear meniscus area (LTMA)--were measured by spectral domain optical coherence tomography before surgery, 1 week, 1 month, and 3 months after surgery. Central, temporal, and nasal corneal nerve densities were measured by confocal microscopy before surgery, 1 month, and 3 months after surgery. After surgery, LTMH and LTMA increased significantly from 1 week to 1 month (P=0.009 and =0.011, respectively) and 1 month to 3 months (P=0.003 and =0.039, respectively); temporal and nasal nerve densities increased significantly from 1 month to 3 months (P<0.001, P=0.016, respectively). Lower tear meniscus area was significantly correlated with central and nasal nerve densities at 1 month (R=0.478 and 0.46, P=0.01 and 0.014, respectively), whereas LTMH and LTMA at 3 months were significantly correlated with central nerve density at 1 month (R=0.449 and 0.608, P=0.017 and 0.001, respectively). Lower tear menisci and peripheral corneal nerves recovered continually after LASIK during the early stage. However, tear volume might depend on residual central corneal nerves at 1 month, rather than on corneal nerve recovery.