title: The effect of age on the corneal subbasal nerve plexus.
abstract: OBJECTIVE
  To measure subbasal nerve density and orientation in normal human corneas across a broad age range.
  
  
  METHODS
  Sixty-five normal corneas of 65 subjects were examined by using tandem scanning confocal microscopy. Ages of subjects ranged from 15 to 79 years (mean 46 +/- 19 years), with 5 subjects from each hemidecade. Subbasal nerve fiber bundles appeared as bright, well-defined linear structures in confocal images of the central cornea. Images from 3 to 8 scans per eye (mean 4.6 +/- 1.8 scans) were randomly presented to a masked observer for analysis. The mean subbasal nerve density (total nerve length [microm] within a confocal image [area = 0.166 mm]), the mean nerve number per confocal scan, and the mean nerve orientation were determined by using a custom software program. Correlations between age and nerve density and age and nerve orientation were assessed by using Pearson correlation coefficients.
  
  
  RESULTS
  The subbasal nerve plexus was visible in the central cornea of all subjects. The mean subbasal nerve density was 8404 +/- 2012 microm/mm (range 4735 to 14,018 microm/mm). The mean subbasal nerve number was 4.6 +/- 1.6 nerves (range 1 to 8 nerves). The mean subbasal nerve orientation was 94 +/- 16 degrees (range 58 to 146 degrees). There was no correlation between age and subbasal nerve density (r = 0.21, P = 0.09) or between age and subbasal nerve orientation (r = -0.19, P = 0.12).
  
  
  CONCLUSIONS
  The density and orientation of the subbasal nerve plexus in the central human cornea does not change with age.
authors: Department of Ophthalmology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA. erie.jay@mayo.edu
authors: Jay C
authors: JC
authors: Erie
authors: Jay W
authors: JW
authors: McLaren
authors: David O
authors: DO
authors: Hodge
authors: William M
authors: WM
authors: Bourne
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D003315:Cornea / Q000294:innervation*; D005260:Female; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D009411:Nerve Endings / Q000166:cytology; D009412:Nerve Fibers; D009882:Ophthalmic Nerve / Q000033:anatomy & histology*