purpose: to compare corneal hysteresis and resistance factor after penetrating keratoplasty (pk) and deep anterior lamellar keratoplasty (dalk) using anwar’s big-bubble technique using the ocular response analyzer. methods: forty-five pk eyes and 23 dalk eyes with keratoconus were compared in terms of corneal hysteresis (ch), corneal resistance factor (crf), goldmann-correlated intraocular pres...

PURPOSE To evaluate corneal deformation with varying intraocular pressure and the dependency of the biomechanical response on the corneal hydration state, modulated by the storage solutions or postmortem period. METHODS Thirty fresh enucleated porcine eyes were used for in vitro whole eye globe inflation experiments. The eyes were separated into five groups and treated with different solution...

PURPOSE Air puff systems have been presented recently to measure corneal biomechanical properties in vivo. In our study we tested the influence of several factors on corneal deformation to an air puff: IOP, corneal rigidity, dehydration, presence of sclera, and in vivo versus in vitro conditions. METHODS We used 14 freshly enucleated porcine eyes and five human donor eyes for in vitro experim...

The Ocular Response Analyzer (ORA) (Reichert Ophthalmic Instruments, Buffalo, NY) allows direct measurement of corneal biomechanical properties. Since its introduction, many studies have sought to elucidate the clinical applications of corneal hysteresis (CH) and corneal resistance factor (CRF). More recently, detailed corneal deformation signal waveform analysis (WA) has potentially expanded t...

The introduction of corneal cross-linking (CXL) has changed the landscape of treatment and management of keratoconus and ectasia after refractive surgery. Previously, treatment options provided only temporary visual rehabilitation without limiting disease progression. Keratoconus and ectasia resulted in significant vision-related reduction in quality of life and a substantial lifetime economic ...

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 to evaluate the influence of anatomical and biomechanical properties of the grafts on iop measurements. methods: this cross-sectional study was conducted on 45 kerat...

PURPOSE To report visual outcomes and corneal biomechanical changes after femtosecond-assisted Intacs SK implantation in keratoconic eyes. METHODS This prospective interventional case series is comprised of 32 keratoconic eyes of 25 patients with mean age of 23.8 ± 5.4 years. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity, refraction, manifest refraction spherical equivalent (...