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At least 37 records · Page 2Linked to original sources

PubMed1977

Orientation of slit pupil and visual streak in the eye of the cat.

The orientation of the visual streak of the cat's retina was compared to that of the long axis of the slit pupil in the same eye. In five paralyzed, anesthetized cats, the retinal projection to the superior colliculus was mapped with electrophysiological techniques. The orientation of the visual streak was estimated from the projection in visual space of the collicular region of high magnification which corresponds to the central projection of the streak. The angle by which the streak was tilted from absolute horizontal was always within one or two degree of the angle by which the pupil axis was tilted from absolute vertical. This relationship was confirmed in three of the animals in which small retinal lesions were placed a known distance from the histologically determined axis of the streak. From the visual coordinates of these lesions, an independent estimate of the streak's orientation was obtained. In each case, the tilt of streak axis from horizontal differed by no more than 0.5 degrees from the tilt of the pupil axis from vertical. The results support the hypothesis that planes containing the long axis of the cat's slit pupil are perpendicular to planes containing the long axis of the visual streak of the same eye.

Animals↗

PubMed1992

[A case of early syphilis presenting general paresis-like symptoms and bilateral tonic pupils].

A 40-year-old man was admitted after 8 months of speech disturbance and locomotive ataxia. He had no seizures, lightning pains, paresthesia, visual loss, bladder disturbance or rectal incontinence. He had never been neurologically or psychiatrically ill and had no history of syphilis. When the patient was admitted, his general physical examination including blood pressure and dermatologic examination was normal. His consciousness was alert. He was found to have a deterioration of mental status such as inability to concentrate, failing memory, amnesia and circumstantiality. His pupils were anisocoric and Achilles jerks were absent. No rigidity of the neck muscles, paralysis and sensory disturbance were recognized. Romberg's sign was absent. The right pupil was 7.0 mm and the left was 6.0 mm in room illumination. The pupils were nonreactive to bright light and both did not constricted to near stimuli. 0.125% pilocarpine eyedrops produced bilateral pupillary constriction. The results indicated bilateral tonic pupils. Laboratory data revealed white cell count of 12,600/mm3 and normal erythrocyte sedimentation rate of 8 mm/hr. Cerebrospinal fluid (CSF) examination revealed the following: opening pressure, 140 mm of water; cell counts, 76/mm2 (mononuclear cells); total protein, 116 mg/dl; glucose, 57 mg/dl. A serum venereal disease research laboratories (VDRL) test was positive in a 1:32 titer confirmed by positive treponema pallidum hemagglutination (TPHA) test in a 1:40,960 titer and positive fluorescent treponemal antibody-absorption (FTA-ABS) test. Serum TPHA-IgM was positive in a 1:320 titer but TPHA-IgG was negative. CSF examination revealed positive TPHA test (titer of 1:2,560) and positive FTA-ABS test.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1979

The influence of 1,3,7-trimethyl-xanthine (caffeine) on the pain-caused dilation of pupil.

The pupil dilation in man caused by pain was investigated. The pain stimulus was induced electrically. The size of the pupil was measured according to the "flying spot scanning method". The accuracy of measurement was increased by computer-assisted addition of repeated responses as well as by elimination of the, usually not considered constriction due to light compensation over Maxwellian view. The pure psycho-sensory dilation shows no initial contraction. The central stimulant 1,3,7-trimethyl-xanthine (caffeine) does not influence the course and adaption of the pupil reaction by a pain stimulus over the threshold. The pupil reaction correlates with the subjective feeling of pain. This suggests that caffeine does not influence the feeling of pain.

Adult↗

PubMed1978

A small pupil binocular indirect ophthalmoscope.

A description of a lightweight small pupil binocular indirect ophthalmoscope is presented. This instrument can be used with well dilated pupils and clear media as any stereoscopic indirect ophthalmoscope. However, the instrument can be simply and easily adjusted for usage in patients with small pupils or opacities of the media. The optical and mechanical principles employed are presented. The technique of utilization for small pupil viewing is outlined.

Dilatation↗

PubMed1978

The refraction of the eye in the relation to spherical aberration and pupil size.

Available theoretical and experimental data on the dependence of the subjective refraction of the eye on spherical aberration and pupil size are reviewed and additional experimental results are presented. Under photopic conditions, refraction varies little (similar to 0.3 DS) with pupil diameter, even when substantial amounts of spherical aberration are present (similar to 1.0 DS). It is argued that this result may be attributed to the insensitivity of optimal focus to spherical aberration at the spatial frequencies involved in photopic refraction, to the Stiles-Crawford effect and to the influence of aberrations other than primary spherical aberration in the outer zones of the pupil. The signficance of these findings is indicated in relation to possible discrepancies between the results of objective and subjective refractions when large pupils are in use.

Humans↗

PubMed1976

Teaching nuns' perceptions of white and black pupils as a function of authoritarianism and other factors.

A sample of 283 teching nuns described the White Pupil, the Black Pupil, and the Ideal Pupil on an adjective description form. A Prejudice score was computed by subtracting the Ideal minus Black differences summed across 52 items from the Ideal minus White differences. Analyses based on 269 subjects revealed that neither age nor amount of prior contact with minorities predicted level of prejiduce. However, high and low-F-scale scorers differed significantly on the Prejudice score and on selected pupil perception factors. Implications in regard to training programs on racial attitudes were discussed.

Black or African American↗

PubMed1975

An investigation of the correlation between abnormal patterns of ocular microtremor and an abnormal pupil reflex in neurological patients.

Twenty-two patients and 7 normal subjects at the Burdenko Institute of Neurosurgery, Moscow, have taken part in an investigation in which the direct light reflex to a brief flash, and the high-frequency microtremor of the eyes, have been recorded. The direct pupil reflex recordings obtained with a flash of 20 msec duration and 100 lux intensity at the plane of the pupil were registered from the right eye of each patient. Ocular microtremor recordings were obtained simultaneously from both eyes of 20 of the patients. A set of criteria of abnormality of ocular microtremor, as judged by visual examination of the records, is proposed by the authors. Abnormality of the pupil reflex is assessed in terms of the amplitude, latent period, and time course of the contraction and relaxation phases of the reflex. A strong correlation has been found between the occurrence of an abnormal ocular tremor record and an abnormal pupil reflex. On the basis of this correlation, the authors propose that ocular tremor recordings may be used in diagnosis as sensitive indicators of brain-stem dysfunction.

Brain Diseases↗

PubMed1976

Tonic pupil: a simple screening test.

The tonic pupil has a typical appearance and characteristic reactions to both light and the near reflex. Testing with Mecholyl (methacholine) is not possible since the drug is no longer manufactured. The reactions of a group of 25 patients with tonic pupil were studied using dilute pilocarpine, and compared with the pupil responses of a separate control group. We found that concentrations of 0.2% pilocarpine produced too many false-positive reactions in the control group and that 0.05% pilocarpine produced an insufficient response. The 0.1% concentration seemed suitable for ordinary clinical examinations and is recommended for pharmacologic confirmation of the diagnosis of tonic (Adie's) pupil.

Adie Syndrome↗

PubMed1975

[The effect of repeated adrenaline application on intraocular pressure and pupil in the rabbit (author's transl)].

The effect of single and repeated topical application of adrenaline on the intraocular pressure and pupil in the rabbit eye was studied using a 2% adrenaline borate and a commercial preparation of 2% adrenaline hydrochloride. On the first day, the hydrochloride gave a more pronounced pressure reduction and pupil diladation than the borate. This was found to be due to the benzalkonium chloride in the chloride preparation causing a better permeability of the adrenaline into the eye. From the second to the fifth day of adrenaline treatment a marked pressure decrease was found from the previous application of the day before. The following adrenaline application gave a hypertensive phase of intraocular pressure lasting two or three hours and a subsequent hypotensive phase lasting more than 24 hrs. The pupil diladation on the second and following days of treatment was not essentially different from the first day considering the observation period of two hours. The hypertensive phase could not be influenced by intravenous or intramuscular propranolol, however, the topical application of propranolol inhibited it completely. Some aspects of adrenergic regulation of the intraocular pressure are discussed.

Animals↗

PubMed1978

[The effect of the pupil as aperture and field stop on the various components of the human electroretinogram (author's transl)].

The electroretinogram (ERG) was recorded in 10 normal subjects under scotopic and photopic conditions with the pupil of one eye constricted and that of the other eye dilated. The human iris, being displaced from the nodal point of the eye, acts not only as an aperture, regulating the retinal illumination, but also as a field stop, limiting the visual angle, especially for large object fields, as in Ganzfeld illumination. This double effect of a constricted pupil clearly influences the Ganzfeld ERG, not only shifting the intensity response functions to higher luminances but also diminishing the maximal responses. Control experiments with smaller test fields, which are less affected by the pupillary field-stop properties, reveal no diminution of the scotopic b-wave amplitudes. Implicit time functions, being nearly independent of the number of receptors stimulated, can be matched by taking into account the pupillary diameter and calculating the actual retinal illumination (Troland). Amplitudes, being highly affected by a decrease of responding neurons due to the angle-limiting field-stop character of the pupil, cannot be matched with regard to the pupillary diameter. This effect is most noticeable in Ganzfeld illumination for the scotopic b-wave, generated mainly by neurons of the peripheral retina, and has less effect on the photopic responses that are generated more centrally.

Adaptation, Ocular↗

PubMed1977

Pupil size after use of marijuana and alcohol.

In an experiment using ten subjects, marijuana produced a dose-related constriction of the pupil at low photopic light levels; alcohol produced no effect on pupil size. The two drugs in combination produced no change in pupil size.

Adult↗

PubMed1979

Pupil responses to intravenous heroin (diamorphine) in dependent and non-dependent humans.

1. Intravenous heroin was administered to volunteers, in doses of 2.5 and 5 mg to non-dependent subjects and does of 1/6, 1/3 and 1/2 of their prescribed daily does of opiates to dependent subjects, and pupillary responses measured before and three times during the 2 h after injection. 2. Tolerance to the miotic effects of heroin in the dependent subjects was demonstrated--larger doses of heroin were needed to produce the same pupil response in dependent subjects than in non-dependent subjects and the duration of action was shorter in the former group. 3. The effect of concurrent oral methadone medication on pupil response to heroin was demonstrated. Subjects prescribed both methadone and heroin showed smaller control pupil diameters and a reduced dose effect to heroin than did subjects prescribed heroin alone.

Dose-Response Relationship, Drug↗

PubMedDate not supplied

The Behr pupil revisited. Anisocoria following cerebrovascular accidents.

Three hundred and sixty-three cases of cerebral infarction were reviewed: 19 had anisocoria. Eighty percent had the larger pupil contralateral to the hemispheric lesion. The mydriasis was associated with long tract signs in all instances. If the abnormal pupil and long tract signs are not on the same side, the long tract signs are the most accurate evidence of the side of thhe hemispheric lesions. When the pupil was 4 mm or larger and reacted sluggishly, the prognosis was poor. The mechanism of the production of the anisocoria is still uncertain; the lesion is probably "cortical" and in the contralateral hemisphere.

Cerebrovascular Disorders↗

PubMed1979

Behavior problems of educationally handicapped and normal pupils.

Male pupils identified as behaviorally disordered, learning disabled, and educable mentally retarded, as well as nonidentified normal boys, were rated by their teachers on the Behavior Problem Checklist. Analyses of the ratings indicated significant differences for pupil category, Behavior Problem Checklist dimension, and category by dimension interaction, but no significant differences for age alone or in interaction with other factors. Categories of pupils were best discriminated from one another on the basis of Conduct Disorder and Personality Problem dimensions of the Behavior Problem Checklist. Results were discussed in terms of some implications for special education and further research suggested by the present findings.

Adolescent↗

PubMed1976

Record in grade school of pupils with epilepsy: an epidemiological study.

In the area of Cesena, Italy, the prevalence of epilepsy was about 3/1,000 among the 13,000 children of school age, 6-14 years. Only half the epileptic pupils had a normal scholastic record. One-third were in special classes, nearly all because of mental retardation due either to birth injury or to damage in infancy. The others (17%) were behind by one or more classes, mainly because of a depressive reaction owing (in half of the intelligent epileptics) mainly to classmates' fear of seizures and to the hostility of classmates' parents after the pupil had a grand mal seizure in school. Teachers had usually not learned how to manage either seizures in the classroom or the problems of pupils with epilepsy.

Adolescent↗

PubMed1992

Drug use and anticipated parental reaction among rural school pupils in Zimbabwe.

Study participants included 285 secondary school pupils in Zimbabwe who responded to a questionnaire assessing alcohol, tobacco, and marijuana use, and anticipated parental reaction to the pupil's drug-taking behavior. Results showed nearly 17% of the sample had used alcohol, 8% used tobacco, and 5% had used marijuana during the past seven days prior to questionnaire administration. Results regarding intentions to use alcohol, tobacco, and marijuana in the future show pupils' interest highest in using alcohol. Nearly 34% indicated intentions to use alcohol during the next year, while 16% reported intentions to use tobacco, and 12.9% indicated intentions to use marijuana. Nearly 17% reported they felt their parents would be favorable to their use of alcohol. Anticipated parental approval for tobacco and marijuana was 13.6% and 10.8%, respectively. Though current use and future intentions among the sample are not as high compared to similar populations in developed countries, this study suggests Zimbabwe should consider expanding its drug education effort in the school setting. Research to identify effective educational strategies to curb further increases in adolescent drug taking behavior also needs to be explored and identified.

Adolescent↗

PubMed1975

Linear and non-linear performance of transducer and pupil in Calliphora retinula cells.

1. Intracellular recordings have been made from the blowfly (Calliphora erythrocephala) retinula cell; apart from the transducer mechanism, these cells also feature a pupil mechanism. 2. At several mean intensity levels, within the apparently linear range of response, frequency characteristics of amplitude and phase and responses to 'delta'-flashes and 'delta'-flash pairs have been obtained. 3. Fourier methods have shown these responses to be mutually compatible, confirming linearity in these circumstances. 4. Non-linear behaviour can be made to appear at the lower frequencies when the modulation depth is increased. 5. Non-linearities can also appear through application of the superposition test: a low frequency sine wave, modulated so as to elicit an apparently linear response, and a high frequence sine wave which does not give rise to non-linearity even at the highest modulation depths can, when superimposed, yield a greater response to the latter when situated at the minima of the former than at its maxima. 6. At frequencies above approximately 1 Hz these superposition non-linearities are attributed to the transducer mechanism gain control. Below this frequency the pupil mechanism takes part considerably in the retinula cell's total observed gain control: its characteristics remain yet to be cleared up. 7. The transducer's linear and non-linear properties fit in closely with those of the Fuortes-Hodgkin model which couples increases in gain and time constants. 8. The Fuortes-Hodgkin model will probably require some quantitative modifications in the originally treated case of Limulus, on account of its pupil. 9. Finally, the merits of Veringa's diffusion model, and the possibility of eventually joining this model with the Fuortes-Hodgkin one are pointed out briefly.

Adaptation, Ocular↗

PubMed1979

[Current educational practices with multiply handicpped pupils -- a problematic approach in special education (author's transl)].

The curricula of schools for the physically handicapped have, as yet, been influenced too much by those of regular schools. Which is why at special schools, too, the primary focus of all educational and therapeutic measures is placed on a qualification of the pupils. Also those pupils who, as a result of the severity of their disability, will not be able to enter vocational training are instructed on the basis of curricula modelled for the non-disabled. The purpose of the following article is to introduce this problem complex which has been present for years but not yet received satisfactory solutions. It is hoped that the described experiences gained with the three groups of pupils will stimulate the discussion.

Child↗