摘要:

Our purpose was to evaluate the presence of stereopsis in a number of small-angle strabismic patients, using several stereotests, and to attempt to associate the presence of stereopsis with certain clinical characteristics of the strabismus—the magnitude of the deviation, the severity of the amblyopia, the depth of the anomalous correspondence, and the etiological category. The evaluation of stereopsis was performed using the Titmus, Ran-dot, Random-dot E, TNO, and Frisby stereotests. Thirty-two percent of the small-angle strabismic patients examined demonstrated no stereopsis on any of the stereotests. Patients having strabismic deviations exceeding 5 δ showing anomalous correspondence on multiple tests, and having had extraocular muscle surgery were the least likely to demonstrate stereopsis. The test that most often indicated the presence of stereopsis was the Titmus stereo test, and the tests that least often indicated the presence of stereopsis were the Random-dot E and the TNO stereo-tests. Our results indicate that careful consideration should be given to the clinical characteristics of the strabismus and the selection of the stereotest when evaluating small-angle strabismic patients for the presence of stereopsis.

ISSN:0093-7002    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

A selective filter, such as the X-chrom lens, which is placed before one eye, serves to create a luminance difference between the two eyes. The amount of the luminance difference is dependent upon the wavelength distribution of the stimulus and could therefore serve as a clue to assist color discrimination. The ability to detect and discriminate levels of luster is investigated. One of three subjects shows a crude ability to discriminate levels of luster. The performance level is such that a filter may aid dichromacy but not anomalous trichromacy.

ISSN:0093-7002    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

When comitant and incomitant vergence disparities are induced for prolonged periods of time, the adaptive state becomes more stable. When the change is complete, the adaptive ability of the oculomotor system to a further disparity should be the same as that before any induced effect. Comitant change was investigated in five subjects who wore a 2δbase-up Fresnel prism for prolonged periods of time (1 to 3 days). Adaptation was periodically monitored with a further 2δbase-up prism. In three subjects the rate of adaptation to the additional prism approached that which occurred before the experiment. In two subjects, both of whom suffered asthenopic symptoms with the initial disparity, adaptation to the additional prism remained slow and incomplete. Incomitant change was investigated in two subjects who wore a –3.00 contact lens-spectacle lens (CL-SL) system for 2 to 3 days. Adaptation was monitored with a further –1.50 CL-SL system at the start and the end of the prolonged wear. Both these subjects had a much faster rate of adaptation at the end of the prolonged period than they had at the beginning.

ISSN:0093-7002    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

The amplitude and implicit time of the P-1 component of the binocular transient pattern visually evoked response (VER) was recorded at four levels of induced aniseikonia. No significant changes were found in these VER parameters over a 10-min test period. Several possible explanations for these observations are presented.

ISSN:0093-7002    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Previous authors have suggested that monocular contact lens wear can induce changes in the contralateral eye. However, most of these contralateral responses have yet to be substantiated or satisfactorily explained. This paper reports a randomized, controlled, single-masked experiment in which corneal thickness, corneal oxygen consumption, and the endothelial bleb response were monitored for 3 hr in both eyes of eight unadapted subjects who wore thick hydrogel lenses on one eye only. No significant contralateral effect was observed in any of the parameters examined. These findings reaffirm the validity of using the contralateral eye as a control in experiments with hydrogel contact lenses.

ISSN:0093-7002    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

The incidence of solution intolerance in 161 soft contact lens patients was about 33% in those using chlorhexidine plus thimerosal chemical disinfecting systems. Those who disinfected their lenses with systems based primarily on thimerosal developed intolerance in 5 to 8% of cases. A family history of allergy appears not to be significant.

ISSN:0093-7002    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

To determine if susceptibility to keratoconus is associated with the histocompatibility (HLA) system, we HLA-typed 39 keratoconic patients and 208 normal controls for 63 HLA-A, -B, and -C antigens. The antigen frequencies for the keratoconic patients did not differ significantly from the frequencies for the control patients. These results suggest that susceptibility to keratoconus is not associated with the HLA system.

ISSN:0093-7002    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

An orange filter (Kodak Wratten 23A) was placed over the nondominant eye of dichromats and evaluated for effectiveness in improving their color perception. A Macbeth color chart, rather than a standard Ishihara test, was used to test color identification. The filter did not improve color identification, but may, under specific color luminance conditions, improve color discrimination, resulting in an improvement in the detection of figure from ground.

ISSN:0093-7002    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

The equivalent oxygen percentage (EOP) technique of Hill and the technique of Rasson and Fatt are two commonly used methods to quantify the oxygen tension underneath a contact lens for the open-eyelid case. This study compares these two techniques. Five subjects and six contact lenses of various center thicknesses and oxygen transmissibilities were used. Each subject wore each lens for which the oxygen tension was measured by these two methods. For lenses of approximately 0.23 mm center thickness, the two methods gave similar oxygen values. For contact lenses significantly thicker or thinner, the two methods gave very different oxygen values. However, these oxygen values were related in a specific manner; a strong linear relation was found for contact lens center thickness vs. the ratio of the two oxygen values found by the two methods.

ISSN:0093-7002    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

A random sample of 2000 persons throughout New Zealand was questioned on the use of and attitudes toward vision care. One-half of the respondents had had a vision examination within the past 4 years. Of those that had been examined, 72% were seen by an optometrist and 22% were seen by an ophthalmologist. Fifty-two percent of the sample wore spectacles or contact lenses, and in the 25 to 34 year age group 12.5% wore contact lenses. The majority (66%) reported no visual problems, and of this group 42% would visit a medical practitioner, 41% an optometrist, and 11% an ophthalmologist if they were to develop a visual problem. At the last visual examination 28% were advised that they did not need a refractive correction, 22% were told their present aid was adequate, and 46% were pre-scribed new spectacles.

ISSN:0093-7002    

出版商:OVID    

年代:1984

数据来源: OVID