title: Variation of laminar depth in normal eyes with age and race.
abstract: OBJECTIVE
  To determine if laminar depth (LD) and prelaminar tissue volume (PTV) are associated with age and race in healthy human eyes.
  
  
  METHODS
  Optic nerve head images from enhanced depth imaging spectral-domain optical coherence tomography of 166 normal eyes from 84 subjects of African descent (AD) and European descent (ED) were manually delineated to identify the principal surfaces: internal limiting membrane, Bruch's membrane (BM), anterior sclera (AS), and anterior surface of the lamina cribrosa. These four surfaces defined the LD and PTV using Bruch's membrane opening (BMO) and AS for reference structures. Generalized estimating equations were used to evaluate whether the effect of age on each outcome was differential by race.
  
  
  RESULTS
  When age was analyzed as a continuous variable, the interaction term between age and race was statistically significant for mean LDBMO (P = 0.015) and mean LDAS (P = 0.0062) after adjusting for axial length and BMO area. For every 1-year increase in age, the LDAS was greater on average by 1.78 μm in AD subjects and less by 1.71 μm in ED subjects. Mean PTV was lower in the older subjects (1248 × 10(6) μm(3) AD, 881 × 10(6) μm(3) ED) compared to the younger subjects (1316 × 10(6) μm(3) AD, 1102 × 10(6) μm(3) ED) in both groups.
  
  
  CONCLUSIONS
  With increasing age, the LD changes differently across racial groups in normal subjects. The LD in ED subjects showed a significantly decreasing slope suggesting that the lamina moves anteriorly with age in this group.
authors.affiliation: Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States.
authors.forename: Lindsay A
authors.initials: LA
authors.lastname: Rhodes
authors.affiliation: Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States.
authors.forename: Carrie
authors.initials: C
authors.lastname: Huisingh
authors.affiliation: Department of Computer and Information Sciences, College of Arts and Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States.
authors.forename: John
authors.initials: J
authors.lastname: Johnstone
authors.affiliation: Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States.
authors.forename: Massimo
authors.initials: M
authors.lastname: Fazio
authors.affiliation: Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States.
authors.forename: Brandon
authors.initials: B
authors.lastname: Smith
authors.affiliation: Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States.
authors.forename: Mark
authors.initials: M
authors.lastname: Clark
authors.affiliation: Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States.
authors.forename: J Crawford
authors.initials: JC
authors.lastname: Downs
authors.affiliation: Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Owsley
authors.affiliation: In Vivo Biomechanics Laboratory, Department of Biomedical Engineering, National University of Singapore, Singapore Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.
authors.forename: Michael J A
authors.initials: MJ
authors.lastname: Girard
authors.affiliation: Department of Medical Physics and Bioengineering, University College London, London, United Kingdom.
authors.forename: Jean Martial
authors.initials: JM
authors.lastname: Mari
authors.affiliation: Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States.
authors.forename: Christopher
authors.initials: C
authors.lastname: Girkin
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001485:Basement Membrane / Q000033:anatomy & histology; D044383:Black People; D016570:Bruch Membrane / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000033:anatomy & histology*; D012044:Regression Analysis; D012590:Sclera / Q000033:anatomy & histology; D041623:Tomography, Optical Coherence; D044465:White People
keywords: lamina cribrosa; laminar depth; spectral-domain optical coherence tomography