Stimulation and recording of dynamic pupillary reflex: the IRIS technique Part 2

Reulen, J. P. H.; Marcus, J. Tim; Gilst, M. J. van; Koops, David; Bos, Jelte E.; Tiesinga, G.; Vries, F. R. de; Boshuizen, K.

doi:10.1007/bf02441824

Cited by 38 publications

(10 citation statements)

References 14 publications

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“…A similar study which evaluated normal corneas demonstrated an increase in PD and decrease in ACD (16) . The only organ related to the autonomic nervous system in the study was the pupil (17) . There was decreased vagal and increased peripheral sympathetic stimulation during VM, and the noted dilation could be explained by this.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of anterior segment parameters using Scheimpflug technology during the Valsalva maneuver in patients with keratoconus

Koçluk¹,

Sukgen²,

Cevher³

2016

Arquivos Brasileiros De Oftalmologia

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Keratoconus (KC) is a noninflammatory eye condition characterized by progressive corneal ectasia, myopia, and irregular astigmatism, generally with bilateral involvement. The etiology and progression of keratoconus have been closely linked to genetic factors, which appear to be multifactorial. However, the majority of cases are not linked to genetic factors (1,2) . It is important to detect progression in KC before making collagen cross-linking (CXL).The Valsalva maneuver (VM) is an attempt at a powerful exhalation against a closed airway. VM is frequently performed during normal daily activities: examples include lifting heavy items, performing physical exercise, vomiting, and coughing. Various physiological changes happen during these activities, including elevated blood pressure, increased intrathoracic pressure, increased peripheral venous pressure, ABSTRACTPurpose: This study aimed to explore the effects of the Valsalva maneuver (VM) on ectatic corneas during anterior segment tomography scans using a Scheimpflug camera. Methods: This prospective observational study included 100 eyes of 50 patients with bilateral keratoconus (KC). Anterior segment tomography was first performed when the patients were in a resting position and immediately repeated as the participant performed VM. Scheimpflug images were taken using a Pentacam®. Results: The mean age of the participants was 24.14 ± 6.59 years. Of the 100 eyes included in the study, 7% had stage 1 KC, 47% had stage 2 KC, 32% had stage 3 KC, and 14% had stage 4 KC. The indices of KC were not significantly affected by VM. Similarly, no statistically significant differences were found between the stages of KC, or with the mean pachymetric progression index during VM. Pupil diameter showed a statistically significant increase during VM (p=0.017). There was a statistically significant decrease in the anterior chamber angle measurement during VM (p=0.001). Maximum curvature power in the front of the cornea decreased more during VM in stage 4 KC than for the other stages (p=0.014). Conclusions:No changes associated with VM were found in the KC indices or the stage of the disease. However, an increase in pupil diameter and a decrease in anterior chamber angle value were found. These changes were comparable to values obtained from previous studies performed on normal corneas.

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Section: Discussionmentioning

confidence: 99%

Evaluation of anterior segment parameters using Scheimpflug technology during the Valsalva maneuver in patients with keratoconus

Koçluk¹,

Sukgen²,

Cevher³

2016

Arquivos Brasileiros De Oftalmologia

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“…In addition, the reliability of the present IR illumination unit which leaves some to be desired, is being replaced at the present time by an improved system. A number of excellent solutions may be found in the literature such as the one described by Reulen and co-workers [34,35]. There are no obstacles which would prevent transforming the present monocular into a binocular recording system.…”

Section: Features Of the Puptrak 10 Systemmentioning

confidence: 95%

“…Development of new pupillographic methods has resulted in an ever increasing complexity of expensive apparatus [34][35][36][37][38][39][40][41][42]. Here, it is shown how an electronic analysis of the pupillomotor light reflex may be achieved using mostly commercially available, standardized equipment.…”

Section: Rationalementioning

confidence: 99%

“…Such noise may be a source of disturbance in open loop systems unless the scan is rigorously controlled during its ....... 0 3 ........................................................................... In the majority of available systems, i.e. systems working with area summation (with the exception of 34,35,36,38,39), only integral quantities (such as the area of the pupil as a function of time) may be measured. This procedure results in high temporal resolution.…”

Section: Features Of the Puptrak 10 Systemmentioning

confidence: 99%

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Puptrak 1.0 — a new semiautomated system for pupillometry with the Octopus perimeter: A preliminary report

Fankhauser¹

1989

Doc Ophthalmol

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A provisional, semiautomated version of a system for automated testing of the afferent pupillary reflex with perimetric methods under controlled conditions is described. The target projected onto the perimeter cupola is used as the stimulus for triggering the pupillary response. In a modification to the Octopus 201, the pupil is illuminated by two IR LED diodes, while the pupillary responses are recorded by the onboard IR sensitive TV camera built into the perimetric unit. Measurements of the pupillary area as a function of time and stimulus luminance have been performed and have resulted in consistent results. Here, one perimetric program, working with stimuli above the threshold for the afferent pupillary light reflex is described. The present setup works with system-specific software and standard hardware, the central data processing unit being a desk-top computer (IBM PC AT-03). The mating of an automated pupillary measuring unit to an automated perimeter may open the door for a more widespread evaluation of the value and the clinical application range of pupillary perimetry and may be of interest in other areas of visual and clinical psychophysics. The shortcomings of the present system, in particular insufficient temporal resolution and lack of full automation, are being removed at the present time.

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“…Eye movements were recorded using infrared oculography (IRIS model 6500; Skalar Medical BV, Delft, The Netherlands) (Reulen et al, 1988). Horizontal recordings with the IRIS system can be made within a range of 7 301.…”

Section: Eye Movement Recordingmentioning

confidence: 99%

Effects of Procyclidine on Eye Movements in Schizophrenia

Ettinger

Kumari²,

Zachariah³

et al. 2003

Neuropsychopharmacol

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Smooth pursuit eye movement (SPEM) and antisaccade deficits are observed in the schizophrenia spectrum and have been used to study the pathophysiology as well as the genetic basis of this condition. The neurotransmitter acetylcholine has been implicated in a number of cognitive processes thought to underlie SPEM and antisaccade performance. This study investigates effects on eye movements of procyclidine, an anticholinergic drug often administered to schizophrenic patients. A total of 13 patients completed a double-blind placebo-controlled crossover design, receiving 15 mg procyclidine and placebo. Seven participants received procyclidine first and placebo second, six participants were tested in the reverse order. SPEM and antisaccade (as well as fixation and prosaccade) eye movements were recorded using infrared oculography. Results showed that procyclidine overall, relative to placebo, mildly worsened SPEM performance, as indicated by nonsignificantly reduced gain (p ¼ 0.08) and increased frequency of intrusive anticipatory saccades during pursuit (p ¼ 0.06). A significant interaction of group and order of administration indicated that procyclidine increased the rate of antisaccade reflexive errors only when administered first; the opposite pattern was observed when placebo was administered first, likely due to the operation of practice effects at second assessment. These findings indicate that acute administration of a clinically relevant dose of procyclidine leads to mild impairments in eye movement performance in schizophrenic patients, suggesting the need to consider this compound in oculomotor studies in schizophrenia. The action of this anticholinergic drug on oculomotor performance is consistent with the hypothesized role of the cholinergic system in the cognitive mechanisms of attention and working memory, processes thought to underlie SPEM and antisaccade performance. Effects of order of administration and practice on the antisaccade task suggest that these factors need to be taken into consideration in future pharmacological studies.

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Stimulation and recording of dynamic pupillary reflex: the IRIS technique Part 2

Cited by 38 publications

References 14 publications

Evaluation of anterior segment parameters using Scheimpflug technology during the Valsalva maneuver in patients with keratoconus

Evaluation of anterior segment parameters using Scheimpflug technology during the Valsalva maneuver in patients with keratoconus

Puptrak 1.0 — a new semiautomated system for pupillometry with the Octopus perimeter: A preliminary report

Effects of Procyclidine on Eye Movements in Schizophrenia

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