title: Evaluation of corneal biomechanical properties following penetrating keratoplasty using ocular response analyzer.
abstract: OBJECTIVE
  To evaluate corneal biomechanical properties in eyes that has undergone penetrating keratoplasty (PK).
  
  
  METHODS
  Retrospective observational study in a tertiary care centre. Data recorded included ocular response analyzer (ORA) values of normal and post-keratoplasty eyes [corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg), and cornea-compensated intraocular pressure (IOPcc)], corneal topography, and central corneal thickness (CCT). Wilcoxon signed rank test was used to analyze the difference in ORA parameter between post-PK eyes and normal eyes. Correlation between parameters was evaluated with Spearman's rho correlation.
  
  
  RESULTS
  The ORA study of 100 eyes of 50 normal subjects and 54 post-keratoplasty eyes of 51 patients showed CH of 8.340 ± 1.85 and 9.923 ± 1.558, CRF of 8.846 ± 2.39 and 9.577 ± 1.631 in post-PK eyes and normal eyes, respectively. CH and CRF did not correlate with post-keratoplasty astigmatism (P = 0.311 and 0.276, respectively) while a significant correlation was observed with IOPg (P = 0.004) and IOPcc (P < 0.001).
  
  
  CONCLUSIONS
  Biomechanical profiles were significantly decreased in post-keratoplasty eyes with significant correlation with higher IOP as compared with that in normal eyes.
authors.affiliation: Cornea and Ocular Surface, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute for Medical Sciences, New Delhi, India.
authors.forename: Vanathi
authors.initials: V
authors.lastname: Murugesan
authors.forename: Ravi
authors.initials: R
authors.lastname: Bypareddy
authors.forename: Mahesh
authors.initials: M
authors.lastname: Kumar
authors.forename: Dada
authors.initials: D
authors.lastname: Tanuj
authors.forename: Panda
authors.initials: P
authors.lastname: Anita
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003315:Cornea / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D003316:Corneal Diseases / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D019781:Corneal Topography / Q000379:methods*; D004548:Elasticity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D015948:Keratoplasty, Penetrating; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D012189:Retrospective Studies; D013997:Time Factors; D014065:Tonometry, Ocular / Q000379:methods*; D055815:Young Adult