RESUMO
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.
Assuntos
Córnea/anatomia & histologia , Humanos , Processamento de Imagem Assistida por Computador , Reprodutibilidade dos Testes , Testes Visuais/instrumentaçãoRESUMO
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. Corneal topography was evaluated utilizing the CMS. The patient was then fitted with a soft contact lens. Next the entire front surface of the contact lens-fitted eye was measured with the CMS. Utilizing those data a piggyback lens was designed. As a result of this fitting technique corneal integrity improved, wearability increased and discomfort dissipated.
Assuntos
Lentes de Contato , Ceratocone/terapia , Adulto , Simulação por Computador , Córnea/fisiopatologia , Humanos , Processamento de Imagem Assistida por Computador , Ceratocone/fisiopatologia , MasculinoRESUMO
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.
Assuntos
Óculos , Optometria , Humanos , Leitura , Acuidade VisualRESUMO
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.
Assuntos
Oftalmoscópios , Óptica e Fotônica/instrumentação , Humanos , Oftalmoscopia/normasRESUMO
A group of 32 patients had their blood pressure measured, fields plotted, intraocular pressure determined, and ocular fundi inspected. The ratio of the blood pressures (systolic and diastolic) to the intraocular pressure is shown to be of limited use as a predictor of glaucomatous damage in the eye.