ISSN:1040-5488    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

In view of the spiralling costs of treating those who are ill, the author urges greater efforts toward disease prevention. Integration of public health education and professional training is advocated. The curriculum of the School of Public Health, University at Albany, is described.

ISSN:1040-5488    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

The author discusses the uses of epidemiology in identifying underserved populations and the positive impact of preventive health care on poverty and social distress. The U.S. Public Health Service document, Healthy People 2000, and its recommendations regarding eye care, are discussed.

ISSN:1040-5488    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

This paper addresses the efficiency of health care delivery in several countries. Confusions arising from comparing the share of gross domestic product going to health care in various countries are discussed, along with the varying levels of coverage enjoyed by the populace. Factors contributing to the rising cost of health care are analyzed and suggestions for improvement are offered.

ISSN:1040-5488    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

The responsibilities of health care providers to society are discussed

ISSN:1040-5488    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Simple formulas based on reduced eyes have been developed to predict the variation in longitudinal chromatic aberration with variation in ametropia or accommodation. Two formulas were developed, one for axial ametropia and one for refractive ametropia. The latter also served as a model for accommodation. The results using the formulas are in close agreement with results obtained using raytracing through more sophisticated models. Combining the results of different methods gives the following predictions of change in chromatic difference of focus, between wavelengths of 400 and 700 nm, with change in each diopter of refractive error or accommodation: axial ametropia 0.012 to 0.017 D (0.6 to 0.9%), refractive ametropia 0.05 D (2.2 to 2.4%), and accommodation 0.04 to 0.05 D (2.1 to 2.6%). The chromatic aberration effects of correcting lenses with low dispersion are intermediate in effect and opposite in sign to the effects of corresponding degrees of axial ametropia and refractive ametropia.

ISSN:1040-5488    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

We have investigated aspects of visual acuity with monovision correction. Binocular distance visual acuity with monovision was approximately equal to monocular visual acuity for addition powers (monocular defocus) of +1.00 to +2.50 D, using both high and low contrast logMAR visual acuity charts. Neither the eye chosen to be defocused (dominant or nondominant) or pupil size (3.5, 5 and 7 mm) affected the binocular visual acuity loss with monovision for high contrast charts. We also investigated the effect of induced residual astigmatism (+0.50, +1.00, and -1.00 D) on binocular distance visual acuity in monovision correction. Residual astigmatism caused a significantly greater reduction of binocular visual acuity in the monovision condition than it did in normal binocular conditions. This effect appears to be related to a process of meridional interocular suppression. It may therefore be of clinical importance to correct low amounts of residual astigmatism in monovision corrections to provide optimum binocular visual acuity.

ISSN:1040-5488    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Purpose. Intraocular pressure (IOP) is influenced by many factors. Our purpose was to determine the immediate response of the IOP to scleral indentation (SI). Methods. Twenty-five subjects had IOP measured using Goldmann applanation tonometry before and after SI. The total indentation time was 40 s. IOP was remeasured in a masked fashion. Results. Average IOP for the control eyes was 15.32 mm Hg (range: 10 to 22 mm Hg) before SI and 14.80 mm Hg (range: 9 to 24 mm Hg) after SI. The average IOP for the subject eyes was 15.08 mm Hg (range: 8 to 22 mm Hg) before SI and 13.14 mm Hg (range: 6 to 22 mm Hg) after SI. Conclusions. These results indicate an average decrease of 1.94 mm Hg for the subject eyes vs. 0.52 mm Hg for the control eyes in response to SI. This represents a statistically significant drop in IOP among the subject eyes in response to SI (p<0.001)

ISSN:1040-5488    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

We compared the effects on rigid contact lens tear pump efficiency of changes in lens overall and optic zone diameter and of changes in lens axial edge lift by measuring corneal oxygen uptake on the right eyes of six human subjects after 5 min of both static and dynamic contact lens wear. Two sets of five lenses were worn by each subject. In set 1, overall diameter varied from 8.2 to 9.4 mm in 0.3-mm steps, with the optic zone diameter being 1.4 mm smaller and a 0.09 mm axial edge lift. In set 2, axial edge lift varied from 0.05 to 0.13 mm in 0.02-mm steps; overall diameter was 8.8 mm, and optic zone diameter was 7.4 mm. For the pooled data, a 0.3-mm decrease in overall diameter was approximately equivalent to a 0.03-mm increase in axial edge lift as a means of enhancing tear pump efficiency. However, considerable intersubject differences were exhibited, with the following increases in axial edge lift being equivalent to the 0.3-mm reduction in overall diameter: 0.01, 0.01, 0.04, 0.06, 0.09, and >0.20 mm. This illustrates that subject factors (i.e., palpebral aperture size, lid-to-cornea geometry, corneal toricity, peripheral corneal topography, lid tension) influence lens positioning, movement, and tear pump efficiency

ISSN:1040-5488    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Ultraviolet (UV) radiation has been proposed as an alternative method for contact lens disinfection. In order for UV radiation to be considered a viable contact lens disinfection method, its effects on lens polymers and parameters must be minimal. To evaluate this, soft contact lenses from each of the four FDA categories, soft lenses with handling tints, and rigid gas permeable (RGP) lenses were exposed to UV radiation in a controlled laboratory setting and their parameters measured. After 20 h of UV exposure, we found statistically significant changes in at least one parameter for each lens type evaluated. Most of these changes were small and within the error of measurement and, therefore, were not considered clinically significant. However, the group 2 soft lenses showed an increase in all four measured parameters—power, center thickness, diameter, and water content. These changes may have an impact on lens fitting characteristics and performance. Other than these changes for group 2 soft lenses, 20 h of UV exposure appeared to have little clinical effect on the contact lenses evaluated. This suggests that UV radiation may prove to be a feasible alternative method of disinfection for most types of contact lenses

ISSN:1040-5488    

出版商:OVID    

年代:1993

数据来源: OVID