title: The relationship between corneal biomechanical properties and confocal microscopy findings in normal and keratoconic eyes.
abstract: OBJECTIVE
  To investigate the relationship between corneal biomechanical properties and confocal microscopy (CM) findings in normal and keratoconic eyes.
  
  
  METHODS
  The study consisted of 28 eyes of 28 healthy volunteers and 23 eyes of 15 patients with keratoconus. The diagnosis of keratoconus was made with corneal topography and clinical findings. The corneal hysteresis (CH) and corneal resistance factor (CRF) were measured by the ocular response analyzer. In vivo CM was performed with NIDEK Confoscan 3. CH and CRF were compared with corneal morphological findings (detailed cell counts of endothelial, stromal, and epithelial cells) in vivo.
  
  
  RESULTS
  CH was 10.1 +/- 1.3 mm Hg in normal eyes and 7.4 +/- 1.5 mm Hg in keratoconic eyes (P < 0.0001). CRF was 10.1 +/- 1.8 mm Hg in normal eyes and 6.2 +/- 1.4 mm Hg in keratoconic eyes (P < 0.0001). CH and CRF were negatively correlated with full-thickness stromal keratocyte density (P < 0.01; r = -0.52 and P < 0.001; r = -0.67, respectively) in healthy eyes. Keratocyte density of the posterior half of the stroma was found to be significantly related with CRF in healthy eyes (beta = -0.404; P = 0.01). There was no significant relationship among CH, CRF, and CM findings in eyes with keratoconus.
  
  
  CONCLUSIONS
  There is a significant relationship between CRF and keratocyte density of the posterior half of the stroma in healthy eyes. Our results suggest that corneal elasticity is related to not only stromal matrix but also cellular structure of the cornea.
authors.affiliation: Department of Ophthalmology, Gulhane Military Medical Academy, Ankara, Turkey. drvolki@yahoo.com
authors.forename: Volkan
authors.initials: V
authors.lastname: Hurmeric
authors.forename: Afsun
authors.initials: A
authors.lastname: Sahin
authors.forename: Gokhan
authors.initials: G
authors.lastname: Ozge
authors.forename: Atilla
authors.initials: A
authors.lastname: Bayer
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D002452:Cell Count; D003315:Cornea / Q000503:physiopathology*; D003319:Corneal Stroma / Q000473:pathology*; D019781:Corneal Topography; D004547:Elastic Tissue / Q000502:physiology*; D004728:Endothelium, Corneal / Q000473:pathology*; D019573:Epithelium, Corneal / Q000473:pathology*; D005260:Female; D005347:Fibroblasts / Q000473:pathology; D006801:Humans; D007640:Keratoconus / Q000503:physiopathology*; D008297:Male; D018613:Microscopy, Confocal