title: Age-related differences in longitudinal structural change by spectral-domain optical coherence tomography in early experimental glaucoma.
abstract: OBJECTIVE
  To characterize age-related differences in the magnitude of spectral-domain optical coherence tomography (SD-OCT) structural change in early experimental glaucoma (EG).
  
  
  METHODS
  Both eyes from four young (1.4-2.6 years) and four old (18.6-21.9 years) rhesus monkeys were imaged at least three times at baseline, and then every 2 weeks after laser-induced, chronic, unilateral IOP elevation until the onset of EG (confocal scanning laser tomographic surface change confirmed twice). Two to 20 weeks after EG onset, animals were euthanized and optic nerve axon counts for all eyes were performed. Masked operators delineated retinal and ONH landmarks in 40 radial B-scans from each eye and imaging session to quantify change from baseline in five SD-OCT neural and connective tissue parameters. The effects of EG, age, and EG × age interactions on the magnitude, rate (magnitude per postlaser time), and IOP responsiveness (magnitude per cumulative IOP insult) of postlaser parameter change were individually assessed using general estimating equation models.
  
  
  RESULTS
  Presac SD-OCT RNFLT and minimum rim width change and postmortem axon loss was not significantly different in old compared with young EG eyes. The rate of change and IOP responsiveness of the parameters anterior lamina cribrosa surface depth relative to Bruch's membrane opening (BMO) and BMO depth relative to peripheral Bruch's membrane were significantly lower (P < 0.05) in the old compared with the young EG eyes.
  
  
  CONCLUSIONS
  At similar postlaser times, levels of cumulative IOP insult and axonal damage, SD-OCT-detected ONH connective tissue structural change is greater in young compared with old monkey EG eyes.
authors.affiliation: Optic Nerve Head Research Laboratory, Devers Eye Institute, Legacy Health, Portland, Oregon, United States Discoveries in Sight Research Laboratories of the Devers Eye Institute, Legacy Health, Portland, Oregon, United States.
authors.forename: Hongli
authors.initials: H
authors.lastname: Yang
authors.affiliation: Optic Nerve Head Research Laboratory, Devers Eye Institute, Legacy Health, Portland, Oregon, United States Discoveries in Sight Research Laboratories of the Devers Eye Institute, Legacy Health, Portland, Oregon, United States.
authors.forename: Lin
authors.initials: L
authors.lastname: He
authors.affiliation: Discoveries in Sight Research Laboratories of the Devers Eye Institute, Legacy Health, Portland, Oregon, United States.
authors.forename: Stuart K
authors.initials: SK
authors.lastname: Gardiner
authors.affiliation: Optic Nerve Head Research Laboratory, Devers Eye Institute, Legacy Health, Portland, Oregon, United States Discoveries in Sight Research Laboratories of the Devers Eye Institute, Legacy Health, Portland, Oregon, United States.
authors.forename: Juan
authors.initials: J
authors.lastname: Reynaud
authors.affiliation: Optic Nerve Head Research Laboratory, Devers Eye Institute, Legacy Health, Portland, Oregon, United States Discoveries in Sight Research Laboratories of the Devers Eye Institute, Legacy Health, Portland, Oregon, United States.
authors.forename: Galen
authors.initials: G
authors.lastname: Williams
authors.affiliation: Optic Nerve Head Research Laboratory, Devers Eye Institute, Legacy Health, Portland, Oregon, United States Discoveries in Sight Research Laboratories of the Devers Eye Institute, Legacy Health, Portland, Oregon, United States.
authors.forename: Christy
authors.initials: C
authors.lastname: Hardin
authors.affiliation: National Institute for Health Research Biomedical Research Centre at Moorfields Eye Hospital National Health Service Foundation Trust and University College London Institute of Ophthalmology, London, United Kingdom.
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Strouthidis
authors.affiliation: Ocular Biomechanics and Biotransport Program, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, United States.
authors.forename: J Crawford
authors.initials: JC
authors.lastname: Downs
authors.affiliation: Discoveries in Sight Research Laboratories of the Devers Eye Institute, Legacy Health, Portland, Oregon, United States.
authors.forename: Brad
authors.initials: B
authors.lastname: Fortune
authors.affiliation: Optic Nerve Head Research Laboratory, Devers Eye Institute, Legacy Health, Portland, Oregon, United States Discoveries in Sight Research Laboratories of the Devers Eye Institute, Legacy Health, Portland, Oregon, United States.
authors.forename: Claude F
authors.initials: CF
authors.lastname: Burgoyne
mesh_terms: D000375:Aging / Q000473:pathology*; D000818:Animals; D001369:Axons / Q000473:pathology; D004195:Disease Models, Animal; D018450:Disease Progression; D005901:Glaucoma / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D021621:Imaging, Three-Dimensional; D007429:Intraocular Pressure; D008253:Macaca mulatta; D009898:Optic Disk / Q000473:pathology*; D013997:Time Factors; D041623:Tomography, Optical Coherence / Q000379:methods*
keywords: BMO minimum rim width; glaucoma; lamina cribrosa; optic nerve head; optical coherence tomography