PURPOSE To examine the symmetry of corneal changes following near work in the fellow eyes of non-amblyopic myopic anisometropes. METHODS Thirty-four non-amblyopic, myopic anisometropes (minimum 1 D spherical equivalent anisometropia) had corneal topography measured before and after a controlled near work task. Subjects were positioned in a headrest to minimise head movements and read continuo...

PURPOSE To evaluate the healing characteristics of cat corneas treated with a new scanning mid-infrared laser system. METHODS Six adult cats were treated with 6-mm diameter photorefractive keratectomy (PRK) corrections. One eye in each animal was untreated as a control and the other was treated with either a -3.00 or -6.00 diopter ablation. The laser was a new Nd:YAG pumped optical parametric...

PURPOSE To determine if a direct relationship exists between the two common measures of corneal topography--axial and instantaneous powers--that are based on corneal slope or curvature, respectively. METHOD The theoretical relationship between axial and instantaneous powers was derived for unrestricted shapes using equations of basic calculus. RESULTS It was found that axial power at any po...

This paper documents a rare nonprogressive developmental disorder-bilateral circumscribed posterior keratoconus-in a 60-year-old man referred for a cataract surgery. For the first time ultrasound biomicroscopy was used to visualise the local anterior bulging of the posterior corneal surface with concomitant thinning of the stroma. The amount of localized posterior depression, corneal thickness ...

This review of corneal topography has three sections: 1. a brief introduction to how corneal topography instruments work. A quantitative comparison of the relative accuracy of slope based and position based instruments is presented. 2. a summary of and commentary on the newly issued ANSI standards for corneal topography. 3. an examination of problems still facing corneal topography. OCIS codes:...

PURPOSE To evaluate the optical aberrations induced by LASIK refractive surgery for myopia on the anterior surface of the cornea and the entire optical system of the eye. METHODS Total and corneal aberrations were measured in a group of 14 eyes (preoperative myopia ranging from -2.5 to -13 D) before and after LASIK surgery. Total aberrations were measured using a laser ray-tracing technique. ...

PURPOSE To evaluate the changes of corneal topography following femtosecond laser and manual clear corneal incision (CCI). METHODS Inflation testing was performed in 14 human eye globes to evaluate the topographic response of the cornea to CCIs. In seven samples (femtosecond laser group), a 2.75-mm three-plane CCI was created using the iFS femtosecond laser (Abbott Medical Optics, Inc., Santa...

This study describes a case of nodular epithelial hyperplasia and stromal alterations in a patient with keratoconus who was submitted to topography-guided photorefractive keratectomy (PRK) followed by corneal collagen cross-linking. Debridement of the epithelial nodule was performed. After a 2-year followup, a new topography-guided PRK was indicated.

Background: The cornea is a complex structure which has protective role, and responsible for about three-quarters of the optical power eye. Pressure from eyelids been implicated in range short- long-term corneal topographical changes. Objective: To evaluate topographic changes after eyelid ptosis surgeries measured by topography Sirius system (CSO, Florence, Italy). Patients Methods: A total 50...