Slide Show 1 Slide Show 2 Slide Show 3
Papers
04/01/2000

PRK ECCENTRICA NEI CHERATOCONI (Eccentric PRK in keratoconus)

AA describe the procedure and the results of a new method for the central and eccentric photoablation in I° and II° keratoconus...

10/01/1999

Soft Contact Lens Application

Corneal topography after about two years of use in rigid contact-lens application. It has been also used , for about a year, for the application of soft contact lenses. Corneal topography permits a more articulated evaluation of the corneal values and subsequent modifications.

05/01/1999

Corneal topography, is more and more common amongst Optician-optometrists

It appears to be the technological novelty of the moment; everyone is talking about it and trying to get information. Numerous speeches at conventions are being made about it. There are innovations and new instruments and at the Mido we will see several of them.

11/01/1997

Corneal Geometry Reconstruction with the Keratron Videokeratographer

The Keratron implemented a spherically-unbiased surface reconstruction method that yields height, axial power, instantaneous curvature without derivation of one quantity from another. Processing innovations resulted in sub-micron height accuracy.

08/05/1996

Instruments validation needs proper models.

I read with some disappointment the article "Evaluating data acquisition and smoothing functions of currently available videokeratoscopes" by M.W.Belin, MD, and C.D.Ratliff, MD1 (from now on "the article" and "the authors" for brevity) whose abstracts Results state that "None of the system accurately imaged all objects." and that "Sources of error included excessive raw data smoothing, inability to read large transitions, loss of accuracy in the periphery, and poor central coverage" and whose abstracts Conclusion is that "The clinician should be aware of the potential limitations of corneal topography when making clinical decisions."a

06/01/1996

Height Measurement of Astigmatic Test Surfaces by a Keratoscope That Uses Plane Geometry Surface Reconstruction

To assess the accuracy with which the Keratron keratoscope (Optikon 2000, Rome, Italy) measured astigmatic test surfaces by a profile reconstruction algorithm within a plane geometry model and to discriminate between error caused by the model and error caused by other factors.

11/01/1995

Assessment of Radial Aspheres by the Arc-Step Algorithm as Implemented by the Keratron Keratoscope

To assess the accuracy with which the Keratron (Optikon 2000, Rome, Italy) measured rotationally symmetric, radially aspheric test surfaces according to an arc-step profile reconstruction algorithm and to discriminate between error caused by the algorithm and error from other sources.

10/27/1995

An Algorithm To Recalculate Topographic Maps From Any Axis For Computer Assisted Videokeratography

A problem that has been frequently attribuited to CAVKs is that curvature maps have always referred to the vertex as normal: a center that has no physiological meaning and, usually, has no relation with the pupil entrance and the line of sight, nor with the corneal apex.

06/01/1995

Assessment of the Power and Height of Radial Aspheres Reported by a Computer-assisted Keratoscope

The two purposes of this study were (a) to assess the accuracy with which a keratoscope, the Topographic Modeling System (TMS-1). calculated the heights and powers of rotationally symmetric, radially aspheric test surfaces and (b) to determine whether the TMS-1 used an axial solution for radius of curvature to determine the power of a sphere that would produce the same semichod as would the test surface on a keratograph.

03/15/1995

Accuracy of Measurement by a New Keratoscope, The Keratron.

The purposes of this study were to assess the accuracy with which the Keratron measured rotationally symmetric, radially aspheric test surfaces and to discriminate the error due to the keratoscope's profile reconstruction algorithm and error from other sources.

03/01/1995

Keratron corneal topography unit can measure aspheric surfaces

Much of the pinpoint accuracy is due to the way the system maps a surface. Most other machines use an 'axial solution', which assumes that there is an axis going through the cornea and uses that to determine the curvature of the cornea.

08/01/1994

The Accuracy of 'Powers' Maps to Display Curvature Data in Corneal Topography Systems

Purpose: To quantify the error introduced by videokeratographic corneal topography devices in using a paraxial formula to calculate power over the entire corneal surface, including areas removed from the central paraxial region where the formula is known to be invalid.