title: Association between corneal biomechanical properties and optic nerve head morphology in newly diagnosed glaucoma patients.
abstract: BACKGROUND
  To investigate the association between corneal biomechanics and optic nerve head morphology in newly diagnosed primary open-angle glaucoma patients.
  
  
  METHODS
  Hospital based prospective study.
  
  
  METHODS
  Forty-two untreated newly diagnosed primary open-angle glaucoma patients.
  
  
  METHODS
  Patients underwent corneal hysteresis measurement using the Ocular Response Analyzer and confocal scanning laser ophthalmoscopy for optic nerve head topography evaluation. One eye was selected randomly for analysis. Data collected included age, race, gender, intraocular pressure and central corneal thickness.
  
  
  METHODS
  Multiple regression analysis (controlling for baseline intraocular pressure and disc area) was used to investigate factors associated with the following optic nerve head topographic parameters: linear cup-to-disc ratio and mean cup depth.
  
  
  RESULTS
  Mean age of participants was 66.7 ± 11.8 years. Corneal hysteresis was the only factor significantly associated with both mean cup depth (correlation coefficient [r] = -0.34, P = 0.03) and cup-to-disc ratio (r = -0.41, P = 0.01). Central corneal thickness was significantly associated with mean cup depth (r = -0.35, P = 0.02), but not with cup-to-disc ratio (r = -0.25, P = 0.13). Although a trend towards a positive association between age and cup-to-disc ratio was identified (r = 0.26, P = 0.08), age was not significantly associated with mean cup depth (r = 0.06, P = 0.72). When comparing fellow eyes of patients with bilateral glaucoma, the eye with higher corneal hysteresis had smaller cup-to-disc ratio in 75% of the cases.
  
  
  CONCLUSIONS
  In untreated newly diagnosed primary open-angle glaucoma patients, those with thinner corneas and mainly lower corneal hysteresis values had a larger cup-to-disc ratio and deeper cup, independently of intraocular pressure values and disc size.
authors.affiliation: Department of Ophthalmology, Federal University of São Paulo Hospital Medicina dos Olhos, São Paulo, Brazil. tiagoprata@ig.com.br
authors.forename: Tiago S
authors.initials: TS
authors.lastname: Prata
authors.forename: Verônica C
authors.initials: VC
authors.lastname: Lima
authors.forename: Lia M
authors.initials: LM
authors.lastname: Guedes
authors.forename: Luis G
authors.initials: LG
authors.lastname: Biteli
authors.forename: Sergio H
authors.initials: SH
authors.lastname: Teixeira
authors.forename: Carlos G
authors.initials: CG
authors.lastname: de Moraes
authors.forename: Robert
authors.initials: R
authors.lastname: Ritch
authors.forename: Augusto
authors.initials: A
authors.lastname: Paranhos
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena / Q000502:physiology*; D003315:Cornea / Q000503:physiopathology*; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D007834:Lasers; D008297:Male; D009887:Ophthalmoscopy; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis* / Q000503:physiopathology; D011446:Prospective Studies; D014065:Tonometry, Ocular