Comparison of biomechanical parameters in penetrating keratoplasty and normal eyes using the Ocular Response Analyser.

Background: To compare corneal hysteresis (CH) and corneal resistance factor (CRF) in eyes 1 year following penetrating keratoplasty (PK) with that of normal eyes using the Ocular Response Analyser.

Methods: Prospective case comparison of 166 normal right eyes and 34 unilateral post-PK eyes presenting to a teaching hospital in Birmingham, UK. The CH, CRF and Goldmann-correlated intraocular pressure, of each eye was measured using the Ocular Response Analyser.

Comparison of corneal biomechanics in pre and post-refractive surgery and keratoconic eyes by Ocular Response Analyser.

Purpose: To compare biomechanical parameters measured by the Ocular Response Analyser (ORA) in the form of corneal hysteresis (CH), corneal resistance factor (CRF) and central corneal thickness (CCT) in eyes before and after excimer laser refractive surgery and keratoconic eyes.

Setting: Teaching Hospital and private eye clinic in Solihull, UK.

Methods: Prospective case comparison of 110 eyes selected for refractive surgery and 132 keratoconic eyes.

Assessment of the biomechanical properties of the cornea with the ocular response analyzer in normal and keratoconic eyes.

Purpose: To compare hysteresis, a novel measure of ocular rigidity (viscoelasticity) in normal and keratoconic eyes.

Methods: The study consisted of 207 normal and 93 keratoconic eyes. Eyes were diagnosed as keratoconic based on clinical examination and corneal topography.

The use of the Reichert ocular response analyser to establish the relationship between ocular hysteresis, corneal resistance factor and central corneal thickness in normal eyes.

Purpose: The aim of this study was to measure ocular hysteresis and corneal resistance factor (CRF), novel methods of analysing ocular rigidity/elasticity and to determine the relationship between central corneal thickness (CCT), hysteresis and CRF in normal subjects.

Design: Prospective, cross-sectional, clinical trial.

Participants: The study included 207 normal eyes.

Central corneal thickness in European (white) individuals, especially children and the elderly, and assessment of its possible importance in clinical measures of intra-ocular pressure.

Purpose: To ascertain the impact of central corneal thickness (CCT, as assessed by pachometry) and central corneal curvature (as assessed by keratometry) on clinical measures of intra-ocular pressure (IOP, as assessed by tonometry), especially in the young and elderly.

Methods: Pachometry, keratometry and tonometry were carried out on three groups, namely children aged 5-15 years, adults aged 32-60 years, and elderly individuals aged between 61 and 82 years. For children, ultrasound pachometry was combined with non-contact tonometry (NCT), specular microscopy was used with Perkins tonometry in the adults, and ultrasound pachometry was used with Perkins tonometry for the elderly.