Reliability and validity of videokeratoscopic measurements.

When a test surface or a cornea is carefully and properly positioned with respect to the Corneal Modeling System (CMS) videokeratoscope, measurements are highly repeatable, but the accuracy of the measurements is dependent on the shape of the surface. For spherical and toroidal surfaces, the CMS provides suitably accurate descriptions of the topography of the surface. For aspheric surfaces the CMS renders less accurate, but still clinically acceptable, topographic descriptions.

The management of keratoconus using the corneal modeling system and a piggyback system of contact lenses.

The purpose of this report is to describe the use of the Corneal Modeling System (CMS) in the quantitative evaluation of the front surface of a soft contact lens on a keratoconic cornea. The management of one eye of a single case is presented as an example. A keratoconic patient fitted with an RGP lens presented with the signs and symptoms of discomfort, reduced wearing time and recurrent corneal erosions.

Preliminary observations on the role of magnetic resonance imaging for polymyositis and dermatomyositis.

The potential use of magnetic resonance imaging (MRI) for inflammatory muscle disorders was evaluated in 13 patients with polymyositis and dermatomyositis. Abnormalities in signal intensity (p = 0.0076) and fat replacement (p = 0.

Multifocal lens decentration and size as a function of reading distance.

A new technique for bifocal size determination and decentration is discussed in detail. Tables based on bifocal power, reading distance and refracting power of the distance lens are presented in order to make bifocal lens selection less complicated.

Comparative analysis of the optical characteristics of binocular indirect ophthalmoscopes.

Recommendations for the design of binocular indirect ophthalmoscopes are made based on a comparative analysis of the optics of various indirects currently available. Significant differences were found to exist in the areas of brightness, stereopsis, small pupil capability, and PD ranges among the brands under study.