title: Corneal Hysteresis and Progressive Retinal Nerve Fiber Layer Loss in Glaucoma.
abstract: OBJECTIVE
  To investigate the relationship between corneal hysteresis (CH) and progressive retinal nerve fiber layer (RNFL) loss in a cohort of patients with glaucoma followed prospectively over time.
  
  
  METHODS
  Prospective observational cohort study.
  
  
  METHODS
  One hundred and eighty-six eyes of 133 patients with glaucoma were followed for an average of 3.8 ± 0.8 years, with a median of 9 visits during follow-up. The CH measurements were acquired using the Ocular Response Analyzer (Reichert Instruments, Depew, New York, USA) and RNFL measurements were obtained at each follow up visit using spectral-domain optical coherence tomography (SDOCT). Random-coefficient models were used to investigate the relationship between baseline CH, central corneal thickness (CCT), average intraocular pressure (IOP), and rates of RNFL loss during follow-up, while adjusting for potentially confounding factors.
  
  
  RESULTS
  Average baseline RNFL thickness was 76.4 ± 18.1 μm and average baseline CH was 9.2 ± 1.8 mm Hg. CH had a significant effect on rates of RNFL progression. In the univariable model, including only CH as a predictive factor along with time and their interaction, each 1 mm Hg lower CH was associated with a 0.13 μm/year faster rate of RNFL decline (P = .011). A similar relationship between low CH and faster rates of RNFL loss was found using a multivariable model accounting for age, race, average IOP, and CCT (P = .015).
  
  
  CONCLUSIONS
  Lower CH was significantly associated with faster rates of RNFL loss over time. The prospective longitudinal design of this study provides further evidence that CH is an important factor to be considered in the assessment of the risk of progression in patients with glaucoma.
authors.affiliation: Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California.
authors.forename: Chunwei
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Tatham
authors.affiliation: Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California.
authors.forename: Ricardo Y
authors.initials: RY
authors.lastname: Abe
authors.affiliation: Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California.
authors.forename: Alberto
authors.initials: A
authors.lastname: Diniz-Filho
authors.affiliation: Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California.
authors.forename: Linda M
authors.initials: LM
authors.lastname: Zangwill
authors.affiliation: Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
authors.affiliation: Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California. Electronic address: fmedeiros@ucsd.edu.
authors.forename: Felipe A
authors.initials: FA
authors.lastname: Medeiros
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D015331:Cohort Studies; D003315:Cornea / Q000503:physiopathology*; D003316:Corneal Diseases / Q000503:physiopathology*; D004548:Elasticity / Q000502:physiology*; D005260:Female; D005901:Glaucoma / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D009412:Nerve Fibers / Q000473:pathology*; D011446:Prospective Studies; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology