title: Assessment of corneal biomechanical properties in normal tension glaucoma and comparison with open-angle glaucoma, ocular hypertension, and normal eyes.
abstract: OBJECTIVE
  To assess the biomechanical properties of corneas in patients with normal tension glaucoma (NTG) and to compare them with those of patients with primary open-angle glaucoma (POAG), ocular hypertension (OHT), and normal controls (N).
  
  
  METHODS
  Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann intraocular pressure (IOPg), and corneal compensated IOP (IOPcc) were obtained using an ocular response analyzer for 28 eyes in 14 patients with NTG, 75 eyes in 38 patients with chronic POAG, 53 eyes of 27 patients with OHT, and 44 eyes of 22 N controls. IOP using Goldmann applanation tonometry (IOPGA) and ultrasonic central corneal thickness (CCT) were also measured for each eye. Analysis of variance test was used for statistical analysis.
  
  
  RESULTS
  CH was significantly lower in the NTG group (9.88±2.02 mm Hg) compared with the N group (11.05±1.53 mm Hg; P<0.01). CRF was significantly lower in the NTG group (9.5±1.89 mm Hg) compared with the POAG group (11.15±2.35 mm Hg; P<0.01) and to the N group (11.00±1.75 mm Hg; P<0.01). CCT was not considered significantly different between the 4 groups. However, IOPcc was found to be significantly lower in NTG group compared with the POAG group and OHT group (P<0.001).
  
  
  CONCLUSIONS
  NTG was associated with significantly lower CRF than chronic POAG and N patients. CH and CRF could be a useful tool in early diagnosis of NTG.
authors: Cataract and Refractive Surgery Department, Fondation Ophtalmologique Adolphe de Rothschild, CEROC, Paris, France. alice.grise.dulac@gmail.com
authors: Alice
authors: A
authors: Grise-Dulac
authors: Alain
authors: A
authors: Saad
authors: Olivia
authors: O
authors: Abitbol
authors: Jean-Luc
authors: JL
authors: Febbraro
authors: Elodie
authors: E
authors: Azan
authors: Christine
authors: C
authors: Moulin-Tyrode
authors: Damien
authors: D
authors: Gatinel
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology; D002908:Chronic Disease; D003315:Cornea / Q000503:physiopathology*; D063171:Corneal Pachymetry; D004548:Elasticity / Q000502:physiology*; D005260:Female; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D057066:Low Tension Glaucoma / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000503:physiopathology; D009901:Optic Nerve Diseases / Q000503:physiopathology; D012189:Retrospective Studies; D014065:Tonometry, Ocular