title: Evaluation of the effect of aging on retinal nerve fiber layer thickness measured by optical coherence tomography.
abstract: OBJECTIVE
  To evaluate the relationship between age and retinal nerve fiber layer (RNFL) thickness in normal subjects, as measured by optical coherence tomography (OCT).
  
  
  METHODS
  One hundred and forty-four normal subjects (144 eyes), ranging from 16 to 84 years of age, were enrolled in this cross-sectional study. The RNFL thickness was determined using OCT with three circle scans 3.4 mm in diameter.
  
  
  RESULTS
  The average RNFL thickness was inversely correlated with age (r = -0.348, p < 0.001). Analyzing the quadrants as a parameter, RNFL thickness in the superior, temporal and inferior quadrants also decreased with age. Using 30-degree segments, there were significant correlations between age and the RNFL thickness of temporal segments (7-11 o'clock). The average RNFL thickness had the highest correlation among all parameters (r = -0.348, p < 0.001). Regarding nasal quadrant thickness, RNFL ratios (average, superior, temporal and inferior RNFL thickness relative to the nasal quadrant thickness) were not significantly correlated with age. The refractive error did not affect RNFL thickness (r = 0.091, p = 0.276).
  
  
  CONCLUSIONS
  Our study revealed that RNFL thickness, in particular in the temporal quadrant, measured by OCT significantly decreased with age. Age has to be taken into consideration when we compare RNFL thickness between normal and glaucomatous eyes.
authors.affiliation: Department of Organ Therapeutics, Division of Ophthalmology, Kobe University Graduate School of Medicine, Kobe, Japan. kannaki@med.kobe-u.ac.jp
authors.forename: Akiyasu
authors.initials: A
authors.lastname: Kanamori
authors.forename: Michael F T
authors.initials: MF
authors.lastname: Escano
authors.forename: Ayako
authors.initials: A
authors.lastname: Eno
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakamura
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Maeda
authors.forename: Ryu
authors.initials: R
authors.lastname: Seya
authors.forename: Kazuki
authors.initials: K
authors.lastname: Ishibashi
authors.forename: Akira
authors.initials: A
authors.lastname: Negi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000648:ultrastructure*; D012016:Reference Values; D012160:Retina / Q000648:ultrastructure*; D014054:Tomography / Q000379:methods