The anterior segment of the vertebrate eye is constructed by proper spatial development of cells derived from the surface ectoderm, which become corneal epithelium and lens, neuroectoderm (posterior iris and ciliary body) and cranial neural crest (corneal stroma, corneal endothelium and anterior iris). Although coordinated interactions between these different cell types are presumed to be essen...

PURPOSE To characterize posterior corneal aberrations in keratoconic (KC) eyes and investigate compensatory effects between anterior and posterior corneal surfaces. METHODS The corneal topography of 113 eyes (37 advanced KC, 31 moderate KC, 14 mild KC, and 31 normal eyes) was used to compute the corneal aberrations. The central 6-mm diameter of both anterior and posterior corneal topographies...

To the Editor: We have previously shown that the Orbscan (Bausch & Lomb, Rochester, New York) was unable to map the corneal surfaces in eyes with shallow anterior chambers , displaying a clonic quad map, and that the clonic quad map disappeared after YAG iridotomy. 1 We now report a case of clonic quad map with Orbscan in a patient with shallow anterior chambers that resolved after pupillary di...

PURPOSE To evaluate changes in anterior corneal topography and higher-order aberrations (HOA) after 14-days of rigid gas-permeable (RGP) contact lens (CL) wear in keratoconus subjects comparing two different fitting approaches. METHODS Thirty-one keratoconus subjects (50 eyes) without previous history of CL wear were recruited for the study. Subjects were randomly fitted to either an apical-t...

PURPOSE To investigate the repeatability and reproducibility of the Visante Omni topography in obtaining topography measurements of rabbit corneas and to develop a post-surgical model of corneal ectasia. METHODS Eight rabbits were used to study the repeatability and reproducibility by assessing the intra- and interobserver bias and limits of agreement. Another nine rabbits underwent different...

A 60-year-old male was referred to the ophthalmologic clinic with aggravated anterior uveitis and corneal edema despite the use of topical and systemic steroids. He had undergone cataract surgery in both eyes 15 years previous. Slit lamp examinations revealed a retained lens fragment in the inferior angle of the anterior chamber, with severe corneal edema and mild anterior uveitis. The corneal ...

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...

PURPOSE To analyze single session, intrauser reliability of a Scheimpflug device for anterior chamber (AC) and corneal parameters. METHODS In this observational study, 100 normal candidates underwent Scheimpflug analysis with Sirius 3D Rotating Scheimpflug Camera and Topography System (Costruzione Strumenti Oftalmici, Italy). Two scans in dark room conditions were performed by the same experi...

AIM To study the posterior corneal topographic changes in eyes with partial flaps during laser assisted in situ keratomileusis (LASIK). METHODS Case records of 16 patients, who had partial flap in one eye during LASIK (group 1) and uncomplicated surgery in the other eye (group 2), were studied. Following occurrence of partial flap intraoperatively, laser ablation was abandoned in all the eyes...