title: Longitudinal detection of optic nerve head changes by spectral domain optical coherence tomography in early experimental glaucoma.
abstract: OBJECTIVE
  We determined if the detection of spectral-domain optical coherence tomography (SDOCT) optic nerve head (ONH) change precedes the detection of confocal scanning laser tomography (CSLT) ONH surface, SDOCT retinal nerve fiber layer (RNFL), scanning laser perimetry (SLP), and multifocal electroretinography (mfERG) change in eight experimental glaucoma (EG) eyes.
  
  
  METHODS
  Both eyes from eight monkeys were tested at least three times at baseline, and then every 2 weeks following laser-induced chronic unilateral IOP elevation. Event and trend-based definitions of onset in the control and EG eyes for 11 SDOCT neural and connective tissue, CSLT surface, SDOCT RNFL, SLP, and mfERG parameters were explored. The frequency and timing of onset for each parameter were compared using a logrank test.
  
  
  RESULTS
  Maximum post-laser IOP was 18 to 42 mm Hg in the EG eyes and 12 to 20 mm Hg in the control eyes. For event- and trend-based analyses, onsets were achieved earliest and most frequently within the ONH neural and connective tissues using SDOCT, and at the ONH surface using CSLT. SDOCT ONH neural and connective tissue parameter change preceded or coincided with CSLT ONH surface change in most EG eyes. The SDOCT and SLP measures of RNFL thickness, and mfERG measures of visual function demonstrated similar onset rates, but occurred later than SDOCT ONH and CSLT surface change, and in fewer eyes.
  
  
  CONCLUSIONS
  SDOCT ONH change detection commonly precedes or coincides with CSLT ONH surface change detection, and consistently precedes RNFLT, SLP, and mfERG change detection in monkey experimental glaucoma.
authors.affiliation: Optic Nerve Head Research Laboratory, Devers Eye Institute, Legacy Health, Portland, Oregon.
authors.forename: Lin
authors.initials: L
authors.lastname: He
authors.forename: Hongli
authors.initials: H
authors.lastname: Yang
authors.forename: Stuart K
authors.initials: SK
authors.lastname: Gardiner
authors.forename: Galen
authors.initials: G
authors.lastname: Williams
authors.forename: Christy
authors.initials: C
authors.lastname: Hardin
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Strouthidis
authors.forename: Brad
authors.initials: B
authors.lastname: Fortune
authors.forename: Claude F
authors.initials: CF
authors.lastname: Burgoyne
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D018450:Disease Progression; D005901:Glaucoma / Q000150:complications / Q000175:diagnosis*; D008253:Macaca mulatta; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis* / Q000209:etiology; D013997:Time Factors; D041623:Tomography, Optical Coherence / Q000379:methods*
keywords: Bruch's membrane opening; glaucoma; lamina cribrosa; optic nerve head; optical coherence tomography; retinal nerve fiber layer