purpose : to compare intraocular pressure (iop) readings measured by the ocular response analyzer (ora) with those measured by the goldmann applanation tonometer (gat) in keratoconic eyes following penetrating keratoplasty (pkp) and evaluate the influence of anatomical and biomechanical properties of the grafts on the iop measurements methods : in this cross-sectional study conducted on 45 kera...

doi:10.3928/1081597X-20110519-01 T raditionally, biomechanical properties of the cornea have been assessed in vitro by measuring stress-strain and Young modulus on corneal strips. In 2005, the Ocular Response Analyzer (ORA; Reichert Technologies, Depew, New York) was launched as the fi rst commercial device claiming to provide in vivo measurements of corneal biomechanics.1 It utilizes a dynamic...

Dear Editor: Changes in the biomechanical properties of the human cornea play an important role in the pathogenesis of corneal dystrophies such as pellucid marginal corneal degeneration and keratoconus. The latter primarily affects young people and is a leading cause of severe visual impairment. Keratoconus is characterized by weakened corneal biomechanics that leads to progressive bulging and ...

PURPOSE To evaluate corneal biomechanical properties in eyes that had previously undergone penetrating keratoplasty (PK) using the ocular response analyzer (ORA). METHODS We recruited 26 patients who had received unilateral PK. Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg), and cornea-compensated intraocular pressure (IOPcc) were mea...

PURPOSE To test the hypothesis that keratoconus and pellucid patients who have glaucoma or are suspected of having glaucoma have lower corneal hysteresis (CH) and/or corneal resistance factor (CRF) measurements compared to controls. METHODS A prospective study at a tertiary eye center of keratoconus and pellucid patients with glaucoma or suspected of having glaucoma, and age-matched keratocon...

Purpose The purpose of this study was to determine the effect of flap thickness on corneal biomechanics after myopic laser in situ keratomileusis (LASIK). Methods This is a prospective controlled non-randomized, institutional study. Patients underwent either epi-LASIK with mitomycin (advanced surface ablation [ASA]), thin-flap LASIK (90 µm head), or thick-flap LASIK (130 µm head). In ASA, the...

PURPOSE To evaluate the performance of the Ocular Response Analyzer (ORA) in the screening of forme fruste keratoconus (FFKc). METHODS A retrospective comparative study was conducted involving 180 eyes. ORA preoperative data were analyzed for 125 normal control eyes (64 patients) undergoing laser in situ keratomileusis (LASIK) without corneal ectasia after 24 months of follow-up and 55 case e...