title: Relationship Between Corneal Hysteresis and Corneal Resistance Factor with Other Ocular Parameters.
abstract: OBJECTIVE
  To evaluate the relationship between corneal hysteresis (CH) and corneal resistance factor (CRF) with age, central corneal thickness (CCT), corneal curvature (KM), corneal volume (CV), and refractive error in naïve eyes.
  
  
  METHODS
  105 healthy subjects (58 male and 47 female) were included in this study. The ages ranged from 19 to 82 years (mean 43.1 ± 15.4 years) and refraction between -11 D and +6 D (mean -0.79 ± 2.95 D). CH and CRF obtained with the Ocular Response Analyzer (ORA) were correlated with age, refractive error, Goldmann Applanation Tonometry (GAT), and with CCT, KM, CV obtained with the Pentacam, and with Corneal-Compensated Intraocular Pressure (IOPcc) and Goldmann-correlated intraocular pressure measurement (IOPg) obtained with ORA. A multivariable mixed effect model was used to evaluate associations among these parameters.
  
  
  RESULTS
  CH ranged from 6.9 to 14.6 mmHg (mean 10.26 ± 1.49 mmHg); CRF ranged from 5.8 to 17 mmHg (mean 10.38 ± 1.64 mmHg). Multivariate analysis showed a statistically significant correlation between CH with CCT (p < 0.001), and KM (p < 0.001), and between CRF with CCT (p < 0.001) and GAT (p < 0.001).
  
  
  CONCLUSIONS
  Our findings support the hypothesis that CH and CRF are related to the corneal shape and thickness, and show a decrease of CH with age.
authors: a Department of Medicine and Surgery , University of Salerno , Salerno , Italy .
authors: Nicola
authors: N
authors: Rosa
authors: b Multidisciplinary Department of Medical , Surgical and Dental Specialities, Seconda Università di Napoli , Naples , Italy .|c Centro Grandi Apparecchiature, Seconda Università di Napoli , Naples , Italy , and.
authors: Michele
authors: M
authors: Lanza
authors: a Department of Medicine and Surgery , University of Salerno , Salerno , Italy .
authors: Maddalena
authors: M
authors: De Bernardo
authors: d Biostatistics Unit, Department of Medicine and Public Health , Seconda Università di Napoli , Naples , Italy.
authors: Giuseppe
authors: G
authors: Signoriello
authors: d Biostatistics Unit, Department of Medicine and Public Health , Seconda Università di Napoli , Naples , Italy.
authors: Paolo
authors: P
authors: Chiodini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001696:Biomechanical Phenomena / Q000502:physiology; D003315:Cornea / Q000033:anatomy & histology / Q000502:physiology*; D063171:Corneal Pachymetry; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation; D004548:Elasticity / Q000502:physiology*; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000503:physiopathology*; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology*; D009929:Organ Size; D012029:Refraction, Ocular / Q000502:physiology*; D014065:Tonometry, Ocular; D055815:Young Adult
keywords: Central corneal thickness; corneal curvature; corneal hysteresis; corneal resistance factor; corneal volume