Simultaneous Estimation of Corneal Topography, Pachymetry, and Curvature.

Identification of objective criteria to correctly diagnose ectatic diseases of the cornea or to detect early stages of corneal ectasia is of great interest in ophthalmology and optometry. Metrics for diagnosis typically employed are curvature maps (axial/sagittal, tangential); elevation map of the anterior surface of the cornea with respect to a reference sphere; and pachymetry (thickness) map of the cornea. We present evidence that currently used curvature maps do not represent the actual curvatures (principal or mean) in a human cornea.

Prevention of bacterial colonization of contact lenses with covalently attached selenium and effects on the rabbit cornea.

Purpose: Although silicone hydrogel materials have produced many corneal health benefits to patients wearing contact lenses, bacteria that cause acute red eye or corneal ulcers are still a concern. A coating that inhibits bacterial colonization while not adversely affecting the cornea should improve the safety of contact lens wear. A covalent selenium (Se) coating on contact lenses was evaluated for safety using rabbits and prevention of bacterial colonization of the contact lenses in vitro.

Opaque contact lens treatment for older children with amblyopia.

Purpose: To investigate the usefulness of daily-wear opaque contact lens treatment for older children with amblyopia.

Methods: A retrospective chart review of all children undergoing opaque contact lens therapy for amblyopia between 2000 and 2003 was performed. All patients were included except for those younger than 5 years of age, those undergoing maintenance treatment only, those lost to follow-up, or those unable to cooperate with Snellen visual acuity testing.

Pupil size and the ablation zone in laser refractive surgery: considerations based on geometric optics.

Purpose: To determine whether the currently accepted method of selecting a minimum ablation zone size for refractive surgery based on dark-adapted pupil diameter is substantiated by geometric optical analysis.

Setting: Department of Ophthalmology and Visual Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA.

Methods: An optical model of the anterior segment was developed to calculate the effective corneal refractive diameter (ECRD), which is the diameter of the area of cornea that refracts all incident light rays arising from objects along the line of sight though the physical pupil (PP).