APSR statement on asthma management (APSR AM-1997): workshop summary. Asian Pacific Society of Respirology

To investigate the relationship between asthenopia of VDT workers and the ocular alignment, we measured far and near alignment of 407 subjects (74 VDT workers with asthenopia, 137 VDT workers without asthenopia, and 196 non-VDT workers) using Total Vision tester (VT-500). There was no relationship between the asthenopia and the records of far alignment test. On the other hand, the incidence of exophoria and convergence insufficiency type in near alignment test was significantly high in the group of VDT workers with asthenopia. From these results, we speculate that cases who have exophoria or show incomplete fusional response measured under the near testing distance (50 cm) tend to complain of asthenopia.     

Effects of target distance and pupil size on letter contrast sensitivity with simultaneous vision bifocal contact lenses

Using simulated presbyopia we measured the effects of target vergence and pupil size on letter contrast sensitivity while subjects wore accurately centered simultaneous vision bifocal contact lenses. These experiments examined the increase in depth of focus provided by two bifocal contact lenses, and the effects of pupil size on near and distance vision. Monocular contrast sensitivity was assessed with three different designs of soft contact lenses. First, as a single vision control, we measured contrast sensitivity with a Bausch & Lomb, Optima 38 lens corrected for distance. We then measured contrast sensitivity with an Allergan Optical, Hydron Echelon, which is a diffractive simultaneous bifocal and a CIBA Vision, Spectrum, which is a concentric design, center-near, two-zone simultaneous vision bifocal. In general both bifocal contact lenses improved contrast sensitivity at near but decreased contrast sensitivity at distance (when compared to the single vision lens). With a fixed 3.5-mm artificial pupil, the Echelon lens had two clear peaks of sensitivity, one at distance (0.00 D) and one at near (-2.00 D), but the Spectrum lens had no clear peaks. Performance of the Spectrum lens depended on its center zone size. Near (-2.00 D) and distance (0.00 D) contrast sensitivity was measured with pupil sizes that ranged from 1 to 6 mm. The results showed that visual performance with a diffractive lens was almost independent of pupil diameter up to 3 to 4 mm but, as predicted, performance with the two-zone lens depended critically on pupil size.     

Functional and anatomical fiber analysis of the posterior commissure (PC) in the cat: evidence for PC fibers of which stimulation elicits non-oculosympathetic pupillary dilation

Pupillary responses were studied by electrical stimulation of the posterior commissure (PC) and the nuclei of origin and termination of PC fibers in the cat. Prior to stimulation experiments, cervical sympathectomy was carried out to study the pupillary responses not mediated by the ocular sympathetic nerve. Pupillary responses were recorded by using an infrared pupillo-analyzing system. The stimulus consisted of a 5 s train of cathodal square wave (0.5 ms duration, 50 Hz) pulses. Stimulation of the PC evoked a pupillary response complex (PRC), which began with a rapid pupillary constriction after the latency of 210-317 ms. The threshold of constriction was 10 or 20 microA. Constriction reached its peak shortly after the onset of the stimulus, then the pupil gradually re-dilated (pupillary escape, PE) even though the stimulus was still lasting. The pupil gradually returned, after stimulus termination, to the size before stimulation in the cases with the pupil area before stimulation larger than 20 mm2. On the other hand, in the cases with smaller pupil area before stimulation (< 20 mm2), rapid constriction and PE were followed, after stimulus termination, by a large dilation (after-dilation, AD). The thresholds of PE and AD were 20 or 40 microA. Pupillary constriction was evoked with a large range of stimulus frequency (1-100 Hz). To evoke PE and AD, stimulus frequencies of 10 and 50 Hz were required respectively, and lower frequencies were ineffective. The peak latency of AD increased in proportion to the increase in stimulus frequency and intensity. Following horseradish peroxidase (dissolved in 5% alkyl-phenol ethylene oxide) injection into the pretectal region where fibers from the PC fan out, retrogradely labeled neurons occurred in many subthalamic, pretectal and midbrain nuclei on the other side. They were classified into three groups in terms of the pupillary response evoked by electrical stimulation; the pupillo-constrictory nuclei (PCNs) of which stimulation evoked constriction with the threshold of 20 microA, the pupillo-dilatory nuclei (PDNs) of which stimulation evoked dilation with the threshold of 20 or 10 microA, and other nuclei with higher thresholds of constriction or dilation. The PDNs were further, classified into two groups (Type 1 and Type 2 PDNs) according to the relationship between stimulus intensity and the peak latency of dilation.(ABSTRACT TRUNCATED AT 400 WORDS)     

Mathematical procedures in data recording and processing of pupillary fatigue waves

Spontaneous pupillary behaviour in darkness provides information about a subject's level of vigilance. To establish infrared video pupillography (IVP) as a reliable and objective test in the detection and quantification of daytime sleepiness, the definition of numerical parameters is an important precondition characterising spontaneous pupil behaviour adequately for further statistical procedures. The correct measurement of the pupil size, even if the lid or eyelashes are occluding the pupil, is of particular concern when testing vigilance. In this case many edge points of the pupil are detected and a fitting procedure is described that fits these edge points to a circle and excludes outliers. The first step of data preparation consists of a mathematical artefact management consisting of blink detection and elimination, followed by interpolation. Second, a fast Fourier transformation is carried out for frequencies from 0.0 to 0.8 Hz for each time segment of 82 s. Results are given in absolute and relative power of each frequency band per time segment and mean values over the entire record of 11 min. Third, the changes of the mean pupillary diameter per data window against time are shown graphically. An additional parameter referring to the pupil's tendency to instability, the pupillary unrest index (PUI), is defined by cumulative changes in pupil size based on mean values of consecutive data sequences. These mathematical procedures provide a high level of quality in both data collection and evaluation of IVP as an objective test of vigilance. In a pilot study, the pupillary behaviour of two groups were measured. One group rated themselves as alert (ten men), the other group as sleepy (12 men). The power and PUI were compared using the Mann-Whitney U-test. Both parameters show significant differences between the two groups.     

Automated pupil perimetry in amblyopia: generalized depression in the involved eye

OBJECTIVE: This study was designed to determine whether the relative afferent pupillary defects observed commonly in amblyopic eyes are associated with a uniform depression of the pupillary light reflex throughout the visual field or solely by a focal decrease in pupillary response near fixation. DESIGN: The authors used pupil perimetry to evaluate the contraction amplitude of the pupil in response to focal light stimuli at 76 points throughout the 30 degrees field in each eye of 28 patients with amblyopia. The "pupil fields" were recorded using a computerized infrared pupillograph linked to a Humphrey Field Analyzer, so that the pupil contraction could be recorded in response to perimetric light stimuli. PARTICIPANTS: Nine patients had strabismic amblyopia, ten had anisometropia, six had a combination of anisometropia and strabismus, and three had deprivation amblyopia due to monocular congenital cataract. MAIN OUTCOME MEASURES: Mean pupillary contraction amplitude for the entire field and focal amplitudes at each tested location were compared. Mixed-model analysis of variance was used to assess effects of perimetry location, type of amblyopia, and interaction effects. RESULTS: The overall average of all the pupil contractions throughout the 30 degrees field was less for the amblyopic eye compared with that of the fellow eye. This decrease in focal pupil response for amblyopic eyes was present in each type of amblyopia and was greatest for deprivation amblyopia. The contraction amplitude was depressed diffusely throughout the pupil field and showed neither focal deficits nor a selective depression about fixation. CONCLUSION: Amblyopia produces a global depression of focal pupillary responses across the entire 30 degrees field.     

受限空间不同照度环境下VDT作业视觉疲劳

受限空间内视觉疲劳是造成事故的主要原因之一。为探究有限空间内光照对视屏显示终端（Visual display terminals,VDT）作业视觉疲劳的影响,选取24名作业人员,在搭建的受限空间平台内进行VDT打字作业1 h,在50～700 lx范围内设置7个光照梯度使用眼动仪采集瞳孔直径数据。将采集数据进行归一化和降噪处理。实验结果表明,随着照度增大,瞳孔直径总体呈减小趋势,且瞳孔?照度关系符合幂函数关系;照度400,550和700 lx环境下瞳孔直径变化率在?12%～8%之间浮动,且随着光照强度的增强,作业人员视觉疲劳发生的程度增加;在低照度50,100和200 lx环境下,瞳孔直径变化率在?8%～4%之间浮动,且随着强度的减弱,作业人员视觉疲劳发生的程度也会增加。本研究提出使用窗口化的瞳孔直径标准差σ判断视觉疲劳出现时间,低照度下的σ峰值出现时间早于高照度下σ峰值出现的时刻,300 lx照度下σ峰值出现的时刻最晚,50～300 lx弱光照下对视觉造成的疲劳程度大于300～700 lx强光照下造成的疲劳。      

Topographic disorientation: two cases

BACKGROUND: There are many theories, but the etiology of chronic fatigue syndrome (CFS) remains unknown. Diagnosticians have set guidelines to try to classify the condition, but its clinical definition is one of exclusion rather than defined by specific clinical testing. The primary goal of this investigation was to find a diagnostic key to define CFS. CFS patients and those diagnosed with the sympathetic hypersensitivity condition called fibromyalgia syndrome (FMS) exhibit identical brain single photon emission computerized tomography (SPECT) images. Therefore, this investigation was initiated to see if CFS patients also had denervation hypersensitivity of the sympathetic system. METHODS: A standardized supersensitivity test was performed using an ocular instillation of two drops of 1.0% phenylephrine. Sixty-two subjects (29 CFS patients and 33 normals) participated in the study. Measurements of pupil size were recorded by pupil gauge and flash photography. A pupillary dilation of greater than 2.5 mm would suggest a sympathetic denervation hypersensitivity. RESULTS: For all participants, a small, but statistically significant increase in pupil size was found (mean of 0.788 mm in normals and 0.931 mm in CFS patients). The change in pupil size in the CFS patients and controls showed substantial overlap and was not statistically significant (t = 0.83, p = 0.42, dF = 60). CONCLUSION: In conclusion, the results suggest that a denervation hypersensitivity of the pupil does not occur in CFS patients. The use of 1.0% topical phenylephrine had no diagnostic value in detecting CSF patients vs. normals.     

Pupillographic sleepiness testing in hypersomniacs and normals

BACKGROUND: Pupillary oscillations in darkness are considered to be a sign of sleepiness. The purpose of this pilot study was to ascertain whether pupillary oscillations were more pronounced in patients with hypersomnia than in normals. METHODS: Seven patients (four with sleep apnea syndrome, three with narcolepsy) and seven age-matched controls underwent pupillography for 11 min in complete darkness. The changes in pupil size were analyzed mathematically to determine quantitatively the amount of pupillary instability. RESULTS: Hypersomniacs had much higher amounts of pupillary oscillations in darkness than normals. The differences were significant. Baseline pupil size did not differ significantly between the two groups. CONCLUSION: This study showed that a pupillographic sleepiness test based on the evaluation of spontaneous pupillary changes in darkness is applicable in hypersomniacs and may facilitate therapy control, i.e. diagnostic grading by measuring daytime sleepiness objectively.     

The use of Baypamun N in crowding-associated infectious respiratory disease: efficacy of Baypamun N (freeze dried product) in 2-week-old veal calves

BACKGROUND: Disturbances of blue color vision and of temporal contrast sensitivity can indicate early damage in glaucoma. For the present study a quick and easy test was devised which examines both functions at one time by testing the temporal contrast sensitivity of a blue flickering light on an intense yellow background. METHODS: Large coextensive background and test fields (85 degrees) are used, making fixation uncritical. Detailed experiments were made in two normal subjects to derive spectral sensitivity curves from flicker-fusion frequency (FFF) versus intensity functions and to obtain complete temporal contrast-sensitivity (De Lange) curves under different levels of adaptation and test lights. After selection of appropriate luminances and one stimulation frequency from these experiments, test-retest variability was studied in four subjects in five repetitions. In addition, normal values were collected from 22 subjects. RESULTS: Spectral sensitivities for two levels of FFF (15 Hz and 44 Hz) agree with Stiles' pi 1 at the low and with pi 4 at the high FFF. Temporal contrast-sensitivity curves show a low-frequency section with peak sensitivity at 1 Hz and a high-frequency section with a peak at around 4 Hz. From the basic experiments the following conditions for the clinical examination were selected: Background luminance 2600 cd/m2, test luminance at 451 nm 0.8 cd/m2, stimulation frequency 4 Hz. The test-retest variability showed an acceptable intraclass correlation co-efficient (0.6). CONCLUSIONS: The present experiments carried out with a very large stimulus led to meaningful results which are in rather good agreement with results reported in the literature on small-field stimuli. The blue-on-yellow flicker test carried out under the conditions mentioned above is a quick and easy test which could be helpful in improving early glaucoma diagnosis.     

Subjective and objective visual acuity testing techniques

The Catford apparatus for determining the objective visual acuity was elevated with 20 normal (20 eyes) and 40 abnormal (75 diseased eyes) patients. The vision of the normal individuals was fogged with neutral-density filters and convex lenses. Eyes with normal or near normal vision showed good correlation between optokinetic response and visual acuity, but no correlation was observed in eyes with poor vision. These findings, which vary from those of Catford, indicate that objective methods of visual acuity testing using a nystagmoid response do not appear useful for general clinical purposes.     

Consistency of pupillary abnormality in children and adolescents with diabetes

Repeat measurements on pupillary adaptation to darkness were performed in a cohort of 66 children and adolescents with insulin-dependent diabetes mellitus (IDDM) (initial age 6.9-17.0 years) after a mean interval of 3.5 years, using a portable pupillometer. While there was a close correlation between the results of the two studies (r = 0.94, p < 0.001), the pupillary dilatation, the ratio of the pupil diameter to the iris diameter % (PD%), had decreased significantly (61.5% vs 62.9%, p < 0.001) over these 3.5 years in children with diabetes. The same measurements were performed on 89 healthy control children in the first study and 66 in the reassessment period and PD% was not significantly different in the two control groups. Five children with diabetes identified as having abnormal pupillary dilatation in the first study were outside the normal range 3.5 years later. In addition 4 children in whom initial testing had been normal, showed abnormality at the time of the second study. None of these children had symptoms of autonomic neuropathy. These findings suggest that abnormality in pupillary adaptation in diabetic children is consistent and increases with time and may serve as an early marker of tissue damage associated with diabetes.     

Can tropicamide eye drop response differentiate patients with progressive supranuclear palsy and Alzheimer's disease from healthy control subjects?

Pupillary dilation in response to dilute tropicamide eye drops has been proposed as a noninvasive diagnostic test to identify patients with Alzheimer's disease (AD). We examined 14 patients with progressive supranuclear palsy (PSP), another related neurodegenerative disorder characterized by severe widespread cholinergic deficits and known central hypersensitivity to cholinergic blockade, to determine whether they also showed a marked pupil dilation after administration of dilute tropicamide eye drops. Both PSP patients and healthy age-matched control subjects had a similar pupillary response comparable with that previously reported in AD patients. Given its lack of specificity, physicians should be very cautious in using this test for identification of patients with AD.     

Processing of observed pupil size modulates perception of sadness and predicts empathy.

Facial autonomic responses may contribute to emotional communication and reveal individual affective style. In this study, the authors examined how observed pupillary size modulates processing of facial expression, extending the finding that incidentally perceived pupils influence ratings of sadness but not those of happy, angry, or neutral facial expressions. Healthy subjects rated the valence and arousal of photographs depicting facial muscular expressions of sadness, surprise, fear, and disgust. Pupil sizes within the stimuli were experimentally manipulated. Subjects themselves were scored with an empathy questionnaire. Diminishing pupil size linearly enhanced intensity and valence judgments of sad expressions (but not fear, surprise, or disgust). At debriefing, subjects were unaware of differences in pupil size across stimuli. These observations complement an earlier study showing that pupil size directly influences processing of sadness but not other basic emotional facial expressions. Furthermore, across subjects, the degree to which pupil size influenced sadness processing correlated with individual differences in empathy score. Together, these data demonstrate a central role of sadness processing in empathetic emotion and highlight the salience of implicit autonomic signals in affective communication. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pupillometric assessment of compensatory effort in a memory search task under physical and pharmacologically-induced suboptimal states

Extensive research has shown that the phasic pupil size (peak level on each trial) is a sensitive measure of the degree of mental effort demanded by a task. In the present study, the validity of the pupil response as an index of mental effort in suboptimal conditions was investigated. Thirteen males (19-29 years) performed a memory and display-search task in a practice session, followed in random order by an oxazepam session, a placebo session, a physical exercise session, and a control session. After both oxazepam and physical exercise, decision times increased, but pupil response increased only after physical exercise. This result was explained by the possibility that under physical fatigue, compensatory effort was exerted, whereas under drug-induced fatigue, subjects seemed unable to compensate for the performance decrement. The pupil response appears to be a valuable tool for gaining more insight into different effects of suboptimal states.     

Abnormal pupillary responses in myasthenia gravis. A pupillographic study

Using an open-loop stimulus (Maxwellian view), the direct pupillary response to light and its derivative curves (velocity and accleration of pupillary reactions) were recorded by infrared video pupillography in seven patients with myasthenia gravis and in three normal subjects. Responses before and after intravenous injection of 5 mg edrophonium hydrochloride were determined. Five of the patients had never taken anticholinesterase drugs except for diagnostic injections of edrophonium while the other two patients had been treated with oral preparations of corticosteroids. Analyses of the pupillary responses showed reduced amplitude, amximal velocity, and maximal acceleration of pupillary constriction in the myasthenic patients. On the other hand, changes in parameters of pupillary dilatation were minimal. Abnormal values returned towards normal within five minutes after edrophonium injection in all patients except in one individual who was being treated with corticosteroids at the time of examination. These results suggest that involvement of the iris sphincter may be common in patients with myasthenia gravis and this can be demonstrated by analysing the pupillary reaction and its derivative curves in response to an open-loop stimulus.     

An initial evaluation of work fatigue and circadian changes as assessed by multiplate posturography

The sensitivity of postural responses to the effects of work fatigue and circadian changes was explored in a pilot study using a specific method of multiplate posturography based on the differential assessment of vertical pressure on four separate platforms for each heel and set of toes of each foot, respectively 8 normal subjects, M.D.s, were given six posturographic examinations immediately before and after three 8-hr. work shifts in the emergency room of a major hospital in Tel-Aviv. 3 posturographic measures (stability, spectral power of postural sway at low frequency of 0.1-0.25 Hz, and unilateral weakening of heel-toe synchronisation) were significantly affected by work fatigue whilst also showing interaction with circadian rhythm. 2 additional measures (power of sway at high frequency of 1.00-3.00 Hz and dysharmonic distribution of weight over the four platforms) were not related to workload but showed significant circadian changes. These effects appeared only on positions involving restricted visual and somatosensory feedback causing vestibular stress. Results justify the application of multiplate posturography as an ancillary tool in measuring objectively the effects of fatigue and circadian changes as well as the interaction between endogenous chronobiological processes and their external conditioning factors (Zeitgebers). Pragmatic implications of the findings in the context of industrial medicine and interdisciplinary efforts to prevent road and air accidents are discussed.     

Gain and delay of human vestibulo-ocular reflexes to oscillation and steps of the head by a reactive torque helmet. I. Normal subjects

Vestibulo-ocular reflexes (VOR) were evaluated with a reactive torque helmet that imposed high-frequency oscillation (2-20 Hz) or step displacements of the head in the horizontal plane. The present paper describes the results in patients with vestibular deficiencies (labyrinthine defective; LD); experimental and analytical techniques and results for normal subjects were described in Part 1 of this paper. The patient groups included: total unilateral LD (related to acoustic neuroma; n = 40); severe (clinically total) bilateral LD (n = 7); bilateral hyporeflexia (n = 14); unilateral hyporeflexia (n = 11); and patients with LD phenomena that had subsided (n = 3). Helmet-induced head steps provided the most specific information. Characteristically, gain was lowered in one direction or both directions after unilateral or bilateral vestibular lesions, respectively; in general, the magnitude of the gain reduction correlated well with the degree of complaints and disability. Surprisingly, delay was systematically prolonged (up to several tens of milliseconds) in all groups of subjects with manifest vestibular pathology. These results suggest that the determination of delay, in addition to gain of the VOR, is feasible and important in the evaluation of vestibular function. The results of head oscillation generally supported the results for steps, but were somewhat less specific. The responses to manually generated head steps roughly agreed with those to helmet-induced steps, but because of the non-uniform acceleration they allowed a less exact analysis of VOR function.     

HLA class I (A, B) and II (DR, DQ) gene and haplotype frequencies in blood donors from Wales

Recent studies have disclosed several oscillations occurring during resting sleep within the frequency range of the classical delta band (0.5-4 Hz). There are at least 3 oscillations with distinct mechanisms and sites of origin: a slow (<1 Hz) cortically-generated oscillation, a clock-like thalamic oscillation (1-4 Hz), and a cortical oscillation (1-4 Hz). The present paper reviews data on these oscillations and the possible mechanisms which coalesce them into the polymorphic waves of slow wave sleep. Data stem from intracellular (over 500 single cell and 50 double impalements) and field potentials recorded from the cortex and thalamus of cats (120 animals) under ketamine and xylazine anesthesia. Other experiments were based on whole night EEG recordings from humans (5 subjects). The frequency of the slow oscillation both in anesthetized animals and in naturally sleeping humans ranged between 0.1 and 1 Hz (89% of the cases being between 0.5 and 0.9 Hz). The slow (<1 Hz) oscillation is reflected in the EEG as rhythmic sequences of surface-negative waves (associated with hyperpolarizations of deeply-lying neurons) and surface-positive K-complexes (representing excitation in large pools of cortical neurons). Through its long-range synchronization, the slow oscillation has the ability to trigger and to group thalamically-generated spindles and two delta (1-4 Hz) oscillations. Finally, it is argued that the analysis of the electroencephalogram should transcend the spectral analyses, by taking into account the shape of the waves and, when possible, the basic mechanisms that generate those waves.     

Changes of auditory word discrimination induced by inversion of the visual field.

Examined auditory discrimination in normal hospital staff members during induced visual conflict. Discrimination of words accompanied by background noise was measured at 6 speech-signal-noise intensity levels during preexperimental (normal vision), experimental (inverted vision), and postexperimental (normal vision) periods. A control condition (no inverted vision) served as a check for the possible effects of practice or fatigue. Significant losses of word discrimination occurred only in the inverted vision condition. Discrimination losses occurred at all intensity levels in which speech was accompanied by noise, prior to walking in the inverted vision condition, following a walking period, and after removal of inversion eyepieces. Results are attributed to a process of visually induced conflict in which Ss were unable to decenter the altered contents of vision. Affinities between reports of induced alterations of experience and pathological alterations of experience are discussed. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anonymity and pseudonymity in whistleblowing to the U.S. Office of Research Integrity

This study attempts to find out whether the motor evoked potential (MEP) elicited by single pulse and slow-rate (1 Hz) repetitive transcranial magnetic stimulation (TMS) can disclose concealed subclinical impairments in the cerebral motor system of patients with minor head injury. The motor response to single pulse TMS (STMS) of the patient group was characterized by significantly higher threshold compared with that of the control group. The central motor conduction time, as well as the peripheral conduction time were normal in all patients pointing to cortical impairment. Two main patterns of MEP changes in response to repetitive TMS (RTMS) were observed in the patient group. A.--progressive decrease of the MEP amplitude throughout the stimulation session to a near complete abolition. B.--irregularity of the amplitude and the waveform of the MEP in a chaotic form. The MEP latency remained stable during the whole stimulation session. The MEP abnormalities recovered gradually over the period of a few months. The higher threshold of the motor response to STMS and the abnormal patterns of the MEP to RTMS seem to reflect transient impairment of cortical excitability or "cortical fatigue" in patients who sustained minor head injures. Further study is needed to evaluated the extent and the pathophysiological mechanisms of the central nervous system fatigue phenomenon following head injury.