title: Does corneal hysteresis correlate with endothelial cell density?
abstract: BACKGROUND
  Our aim was to determine if there is a correlation between corneal biomechanical properties, endothelial cell count, and corneal pachymetry in healthy corneas.
  
  
  METHODS
  Ninety-two eyes of all subjects underwent complete ocular examination, including intraocular pressure measurement by Goldmann applanation tonometer, objective refraction, and slit-lamp biomicroscopy. Topographic measurements and corneal pachymetry were performed using a Scheimpflug-based (Pentacam, Oculus, Germany) corneal topographer. Corneal hysteresis (CH) and corneal resistance factor (CRF) were measured with an Ocular Response Analyzer (ORA, Reichert Ophthalmic Instruments, Buffalo, NY). Endothelial cell count measurement was done using a specular microscope (CellChek, Konan, USA).
  
  
  RESULTS
  Right eye values of the subjects were taken for the study. The mean CH was 11.5±1.7 mmHg and the mean CRF was 11.2±1.4 mmHg. Mean intraocular pressure was 15.3±2.3 mmHg. The mean endothelial cell count was 2754±205 cells/mm2. No correlation was found between biomechanical properties of cornea and endothelial cell count. There was a significant positive correlation between CH, CRF, and corneal thickness (p<0.001; r=0.79).
  
  
  CONCLUSIONS
  The corneal biomechanical properties significantly correlated with corneal thickness. We found no correlation between CH and CRF with the endothelial cell density in normal subjects.
authors.affiliation: Department of Ophthalmology, Uludag University, School of Medicine, Bursa, Turkey.
authors.forename: Berna
authors.initials: B
authors.lastname: Akova-Budak
authors.affiliation: Department of Ophthalmology, Uludag University, School of Medicine, Bursa, Turkey.
authors.forename: Sertaç Argun
authors.initials: SA
authors.lastname: Kıvanç
mesh_terms: D065966:Absorption, Physicochemical; D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D002452:Cell Count; D003315:Cornea / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D004548:Elasticity; D042783:Endothelial Cells / Q000166:cytology*; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D014065:Tonometry, Ocular / Q000295:instrumentation / Q000379:methods*; D014783:Viscosity; D055815:Young Adult