title: Determinants of perimacular inner retinal layer thickness in normal eyes measured by Fourier-domain optical coherence tomography.
abstract: OBJECTIVE
  To determine the effects of age, sex, spherical equivalent, axial length, anterior chamber depth, optic disc area, and central corneal thickness on perimacular inner retinal layer thickness in the normal human eye as measured by Fourier-domain optical coherence tomography (FD-OCT).
  
  
  METHODS
  In this cross-sectional observational study, 182 Korean healthy subjects aged from 22 to 84 years were included. To obtain the inner retinal layer thickness, perimacular ganglion cell complex thickness, which extends from the internal limiting membrane to the inner nuclear layer, was measured by FD-OCT on one randomly selected eye of each subject. Linear regression analyses of the effects of demographic and clinical variables, including age, sex, spherical equivalent, axial length, anterior chamber depth, optic disc area, and central corneal thickness, on perimacular inner retinal layer thickness were performed.
  
  
  RESULTS
  The mean inner retinal layer thickness for the entire population was 93.87 μm. Thinner inner retinal layer measurements were associated with older age (P = 0.010) and greater axial length (P = 0.021). Mean inner retinal layer thickness decreased by approximately 1.59 μm for every decade of age and by approximately 1.56 μm for every 1-mm greater axial length. There was no relationship between inner retinal layer thickness and sex, anterior chamber depth, optic disc area, or central corneal thickness.
  
  
  CONCLUSIONS
  Inner retinal layer thickness, as measured by FD-OCT, varies significantly with age and axial length. The effect is small but clinically relevant in the interpretation of inner retinal layer thickness measurements.
authors.affiliation: Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seodaemun-gu, Seoul, Korea.
authors.forename: Na Rae
authors.initials: NR
authors.lastname: Kim
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Junwon
authors.initials: J
authors.lastname: Lee
authors.forename: Eun Suk
authors.initials: ES
authors.lastname: Lee
authors.forename: Gong Je
authors.initials: GJ
authors.lastname: Seong
authors.forename: Chan Yun
authors.initials: CY
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000867:Anterior Chamber / Q000033:anatomy & histology; D058452:Axial Length, Eye / Q000033:anatomy & histology*; D003315:Cornea / Q000033:anatomy & histology; D003430:Cross-Sectional Studies; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000033:anatomy & histology; D012016:Reference Values; D012160:Retina / Q000033:anatomy & histology; D012165:Retinal Ganglion Cells / Q000166:cytology*; D055211:Retinal Photoreceptor Cell Inner Segment; D012737:Sex Factors; D041623:Tomography, Optical Coherence; D055815:Young Adult