title: Significance of corneal biomechanical properties in patients with progressive normal-tension glaucoma.
abstract: OBJECTIVE
  To investigate the clinical significance of corneal biomechanical properties assessed using an ocular response analyser in patients with progressing normal-tension glaucoma (NTG).
  
  
  METHODS
  In this retrospective study, we included 82 eyes of 82 NTG patients who had been receiving topical anti-glaucoma medications. Patients were allocated to two groups based on the mean value of corneal hysteresis (CH) and the status of progression. The assessment of progression was based on the trend analysis using mean deviation slope. Uni- and multivariable logistic analyses were constructed to identify factors associated with increased odds of progression, including CH, central corneal thickness (CCT), and retinal nerve fibre layer (RNFL) thickness.
  
  
  RESULTS
  Forty-six eyes (56.1%) reached the progression criteria. Eyes with progression had lower CCT (530.2±38.6 vs 549.4±38.3 μm, p=0.03), thinner average RNFL thickness (70.6±16.1 vs 82.8±17.4 μm, p<0.01), lower CH (9.4±1.3 vs 10.8±1.4 mm Hg, p<0.01), and lower corneal resistance factor (9.3±1.3 vs 10.4±1.8 mm Hg, p<0.01) than eyes without progression. CH and CCT were significantly correlated (r=0.44, p<0.01). Upon multivariable analysis, CH (β (B)=0.32 per mm Hg lower, p<0.01) and average RNFL thickness (β=0.96 per μm lower, p=0.04) remained statistically significant.
  
  
  CONCLUSIONS
  Corneal biomechanical properties are correlated and associated with the progression of visual field damage in NTG patients. These findings suggest that CH can be used as one of the prognostic factors for progression, independent of corneal thickness or intraocular pressure.
authors.affiliation: Department of Ophthalmology, Institute of Ophthalmology & Optometry, Ewha Womans University School of Medicine, Seoul, Republic of Korea.
authors.forename: Jong Hyuk
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Ophthalmology, Institute of Ophthalmology & Optometry, Ewha Womans University School of Medicine, Seoul, Republic of Korea.
authors.forename: Roo Min
authors.initials: RM
authors.lastname: Jun
authors.affiliation: Department of Ophthalmology, Institute of Ophthalmology & Optometry, Ewha Womans University School of Medicine, Seoul, Republic of Korea.
authors.forename: Kyu-Ryong
authors.initials: KR
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001696:Biomechanical Phenomena / Q000502:physiology; D003315:Cornea / Q000502:physiology*; D018450:Disease Progression; D004548:Elasticity / Q000502:physiology*; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D057066:Low Tension Glaucoma / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D009898:Optic Disk / Q000473:pathology; D009901:Optic Nerve Diseases / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D012165:Retinal Ganglion Cells / Q000473:pathology; D012189:Retrospective Studies; D014065:Tonometry, Ocular; D014786:Vision Disorders / Q000175:diagnosis / Q000503:physiopathology; D014794:Visual Fields / Q000502:physiology
chemical_list: D000959:Antihypertensive Agents
keywords: Cornea; Glaucoma