Gaze-contingent flicker pupil perimetry detects scotomas in patients with cerebral visual impairments or glaucoma

The pupillary light reflex is weaker for stimuli presented inside as compared to outside absolute scotomas. Pupillograph perimetry could thus be an objective measure of impaired visual processing. However, the diagnostic accuracy in detecting scotomas has remained unclear. We quantitatively investigated the accuracy of a novel form of pupil perimetry. The new perimetry method, termed gaze-contingent flicker pupil perimetry, consists of the repetitive on, and off flickering of a bright disk (2 hz; 320 cd/m; 4° diameter) on a gray background (160 cd/m) for 4 seconds per stimulus location. The disk evokes continuous pupil oscillations at the same rate as its flicker frequency, and the oscillatory power of the pupil reflects visual sensitivity. We monocularly presented the disk at a total of 80 locations in the central visual field (max. 15°). The location of the flickering disk moved along with gaze to reduce confounds of eye movements (gaze-contingent paradigm). The test lasted ~5 min per eye and was performed on 7 patients with cerebral visual impairment (CVI), 8 patients with primary open angle glaucoma (age >45), and 14 healthy, age/gender-matched controls. For all patients, pupil oscillation power (FFT based response amplitude to flicker) was significantly weaker when the flickering disk was presented in the impaired as compared to the intact visual field (CVI: 12%, AUC = 0.73; glaucoma: 9%, AUC = 0.63). Differences in power values between impaired and intact visual fields of patients were larger than differences in power values at corresponding locations in the visual fields of the healthy control group (CVI: AUC = 0.95; glaucoma: AUC = 0.87). Pupil sensitivity maps highlighted large field scotomas and indicated the type of visual field defect (VFD) as initially diagnosed with standard automated perimetry (SAP) fairly accurately in CVI patients but less accurately in glaucoma patients. We provide the first quantitative and objective evidence of flicker pupil perimetry's potential in detecting CVI-and glaucoma-induced VFDs. Gaze-contingent flicker pupil perimetry is a useful form of objective perimetry and results suggest it can be used to assess large VFDs with young CVI patients whom are unable to perform SAP

Campimetry with Offset Stimulus and Dynamic Fixation

The dark-on-bright (negative contrast, light decremental, light offset) stimulus and dynamic fixation target are non-conventional and their usefulness in visual field examination has not been fully documented before. The utility of light offsets (i.e. offset stimuli) and dynamic fixation was investigated for kinetic and static perimetry on a tangent screen without or with automation and the results were compared to those from conventional bright-on-dark (positive contrast, light incremental, light onset) stimuli and static fixation. The disappearance eccentricities of offset and onset stimuli of equal size were determined in eight normal eyes, using dynamic fixation technique at two different levels of surrounding illumination. Kinetic' offset stimulus has a smaller "isoptre" than onset stimulus and, the variation of ambient illumination has less effect on the visibility of offset stimulus. The Oculokinetic Campimetry (OKC) with a constantly exposed offset stimulus was performed in 366 glaucomatous eyes and 217 normal eyes. When a 1.5 mm stimulus was used, a true positive OKC result was obtained in 45% of eyes with relative scotomas and 81% of eyes with small absolute scotomas. A false positive result was obtained in 9% of patients aged 60-70 yrs and 13% of patients older than 70 yrs. When a 3 mm stimulus was used in the glaucomatous patients above the age of 60 yrs, the OKC test was positive in 33% of eyes with relative scotomas and 56% of eyes with small absolute scotomas while none of the control subjects produced a positive result. In 63% of the eyes, abnormal OKC results reflected smaller scotomas than those to the conventional visual field tests, suggesting underestimation of the topographical extent of the scotomas. Inside the absolute scotomas, constantly exposed offset stimulus was still detectable with 19% - 67% frequency between

Gaze-Contingent Flicker Pupil Perimetry Detects Scotomas in Patients With Cerebral Visual Impairments or Glaucoma

Background: The pupillary light reflex is weaker for stimuli presented inside as compared to outside absolute scotomas. Pupillograph perimetry could thus be an objective measure of impaired visual processing. However, the diagnostic accuracy in detecting scotomas has remained unclear. We quantitatively investigated the accuracy of a novel form of pupil perimetry.Methods: The new perimetry method, termed gaze-contingent flicker pupil perimetry, consists of the repetitive on, and off flickering of a bright disk (2 hz; 320 cd/m2; 4° diameter) on a gray background (160 cd/m2) for 4 seconds per stimulus location. The disk evokes continuous pupil oscillations at the same rate as its flicker frequency, and the oscillatory power of the pupil reflects visual sensitivity. We monocularly presented the disk at a total of 80 locations in the central visual field (max. 15°). The location of the flickering disk moved along with gaze to reduce confounds of eye movements (gaze-contingent paradigm). The test lasted ~5 min per eye and was performed on 7 patients with cerebral visual impairment (CVI), 8 patients with primary open angle glaucoma (age >45), and 14 healthy, age/gender-matched controls.Results: For all patients, pupil oscillation power (FFT based response amplitude to flicker) was significantly weaker when the flickering disk was presented in the impaired as compared to the intact visual field (CVI: 12%, AUC = 0.73; glaucoma: 9%, AUC = 0.63). Differences in power values between impaired and intact visual fields of patients were larger than differences in power values at corresponding locations in the visual fields of the healthy control group (CVI: AUC = 0.95; glaucoma: AUC = 0.87). Pupil sensitivity maps highlighted large field scotomas and indicated the type of visual field defect (VFD) as initially diagnosed with standard automated perimetry (SAP) fairly accurately in CVI patients but less accurately in glaucoma patients.Conclusions: We provide the first quantitative and objective evidence of flicker pupil perimetry's potential in detecting CVI-and glaucoma-induced VFDs. Gaze-contingent flicker pupil perimetry is a useful form of objective perimetry and results suggest it can be used to assess large VFDs with young CVI patients whom are unable to perform SAP

Standards in Pupillography

The number of research groups studying the pupil is increasing, as is the number of publications. Consequently, new standards in pupillography are needed to formalize the methodology including recording conditions, stimulus characteristics, as well as suitable parameters of evaluation. Since the description of intrinsically photosensitive retinal ganglion cells (ipRGCs) there has been an increased interest and broader application of pupillography in ophthalmology as well as other fields including psychology and chronobiology. Color pupillography plays an important role not only in research but also in clinical observational and therapy studies like gene therapy of hereditary retinal degenerations and psychopathology. Stimuli can vary in size, brightness, duration, and wavelength. Stimulus paradigms determine whether rhodopsin-driven rod responses, opsin-driven cone responses, or melanopsin-driven ipRGC responses are primarily elicited. Background illumination, adaptation state, and instruction for the participants will furthermore influence the results. This standard recommends a minimum set of variables to be used for pupillography and specified in the publication methodologies. Initiated at the 32nd International Pupil Colloquium 2017 in Morges, Switzerland, the aim of this manuscript is to outline standards in pupillography based on current knowledge and experience of pupil experts in order to achieve greater comparability of pupillographic studies. Such standards will particularly facilitate the proper application of pupillography by researchers new to the field. First we describe general standards, followed by specific suggestions concerning the demands of different targets of pupil research: the afferent and efferent reflex arc, pharmacology, psychology, sleepiness-related research and animal studies

Microsaccades in applied environments: Real-world applications of fixational eye movement measurements

Across a wide variety of research environments, the recording of microsaccades and other fixational eye movements has provided insight and solutions into practical problems. Here we review the literature on fixational eye movements—especially microsaccades—in applied and ecologically-valid scenarios. Recent technical advances allow noninvasive fixational eye movement recordings in real-world contexts, while observers perform a variety of tasks. Thus, fixational eye movement measures have been obtained in a host of real-world scenarios, such as in connection with driver fatigue, vestibular sensory deprivation in astronauts, and elite athletic training, among others. Here we present the state of the art in the practical applications of fixational eye movement research, examine its potential future uses, and discuss the benefits of including microsaccade measures in existing eye movement detection technologies. Current evidence supports the inclusion of fixational eye movement measures in real-world contexts, as part of the development of new or improved oculomotor assessment tools. The real-world applications of fixational eye movement measurements will only grow larger and wider as affordable high-speed and high-spatial resolution eye trackers become increasingly prevalent

Conducción, tecnología, intervención y riesgo vial en conductores españoles

Lamentablemente, los siniestros de tráfico siguen siendo una de las primeras causas de mortalidad y lesividad en la población española y se han convertido en una pandemia a nivel mundial. La Organización Mundial de la Salud, calcula que alrededor de 1,35 millones de personas siguen muriendo en el mundo anualmente, a causa de los siniestros viales. Actualmente nos encontramos ante un nuevo Decenio de Acción para la Seguridad Vial 21-30, declarado por la Asamblea General de Naciones Unidas, que solicita continuar trabajando para reducir a la mitad la mortalidad y lesividad derivada de estos siniestros. Números estudios siguen afirmando que el factor humano está directamente relacionado con la siniestralidad vial y que, entre el 70% y el 90% de los siniestros, se explican por diversos errores humanos. Al objeto de reducir la siniestralidad vial y mejorar la movilidad, esta Tesis de Psicología por Compendio de Publicaciones investiga sobre factores emergentes en seguridad vial con efectos determinantes en la población conductora española. Estos factores han sido agrupados en tres ejes temáticos relacionados con la tecnología y la automatización de los vehículos, la salud visual y las conductas infractoras reincidentes, que dieron como resultado cuatro publicaciones científicas. Para el desarrollo de las investigaciones, se elaboraron herramientas específicas de recogida de datos, se realizó investigación documental y de campo, con muestras robustas y representativas a nivel nacional y se analizaron los datos obtenidos en busca de respuestas prácticas a estos factores emergentes. En la parte final de este documento, se encuentran los artículos científicos resultantes y un resumen en castellano de cada uno de ellos

A study of the relationship between age and performance on computer -assisted rehabilitation tasks for children

The purpose of this study was to investigate relationships between performance by children on computerized rehabilitation tasks, age and standardized assessment instruments. It was hypothesized that children\u27s performance would differ by age on standardized assessment instruments and computer tasks developed for rehabilitation of attention, visual/perceptual and visual memory skills.;Two hundred five children from three schools in Chesapeake, Virginia, completed the Benton Visual Retention Test - Administration C, the Trail Making Test (B), and six computer tasks. Significant correlation was found between age, and both assessment instruments as well as five of the computer tasks. Standardized instruments correlated with one of each type of computer task for attention, visual/perceptual and visual memory skills. Additionally, correlation was found between one computer program and the Trail Making Test for visual/perceptual skills.;Further study is needed to develop standardization of these computer tasks for use rehabilitation of attention, visual/perceptual and memory skills dysfunction

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 144

This bibliography lists 257 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1975

Interventions for visual field defects in people with stroke

BACKGROUND:Visual field defects are estimated to affect 20% to 57% of people who have had a stroke. Visual field defects can affect functional ability in activities of daily living (commonly affecting mobility, reading and driving), quality of life, ability to participate in rehabilitation, and depression and anxiety following stroke. There are many interventions for visual field defects, which are proposed to work by restoring the visual field (restitution); compensating for the visual field defect by changing behaviour or activity (compensation); substituting for the visual field defect by using a device or extraneous modification (substitution); or ensuring appropriate diagnosis, referral and treatment prescription through standardised assessment or screening, or both. OBJECTIVES:To determine the effects of interventions for people with visual field defects after stroke. SEARCH METHODS:We searched the Cochrane Stroke Group Trials Register, the Cochrane Eyes and Vision Group Trials Register, CENTRAL, MEDLINE, Embase, CINAHL, AMED, PsycINFO, and PDQT Databse, and clinical trials databases, including ClinicalTrials.gov and WHO Clinical Trials Registry, to May 2018. We also searched reference lists and trials registers, handsearched journals and conference proceedings, and contacted experts. SELECTION CRITERIA:Randomised trials in adults after stroke, where the intervention was specifically targeted at improving the visual field defect or improving the ability of the participant to cope with the visual field loss. The primary outcome was functional ability in activities of daily living and secondary outcomes included functional ability in extended activities of daily living, reading ability, visual field measures, balance, falls, depression and anxiety, discharge destination or residence after stroke, quality of life and social isolation, visual scanning, adverse events, and death. DATA COLLECTION AND ANALYSIS:Two review authors independently screened abstracts, extracted data and appraised trials. We undertook an assessment of methodological quality for allocation concealment, blinding of outcome assessors, method of dealing with missing data, and other potential sources of bias. We assessed the quality of evidence for each outcome using the GRADE approach. MAIN RESULTS:Twenty studies (732 randomised participants, with data for 547 participants with stroke) met the inclusion criteria for this review. However, only 10 of these studies compared the effect of an intervention with a placebo, control, or no treatment group, and eight had data which could be included in meta-analyses. Only two of these eight studies presented data relating to our primary outcome of functional abilities in activities of daily living. One study reported evidence relating to adverse events.Three studies (88 participants) compared a restitutive intervention with a control, but data were only available for one study (19 participants). There was very low-quality evidence that visual restitution therapy had no effect on visual field outcomes, and a statistically significant effect on quality of life, but limitations with these data mean that there is insufficient evidence to draw any conclusions about the effectiveness of restitutive interventions as compared to control.Four studies (193 participants) compared the effect of scanning (compensatory) training with a control or placebo intervention. There was low-quality evidence that scanning training was more beneficial than control or placebo on quality of life, measured using the Visual Function Questionnaire (VFQ-25) (two studies, 96 participants, mean difference (MD) 9.36, 95% confidence interval (CI) 3.10 to 15.62). However, there was low or very-low quality evidence of no effect on measures of visual field, extended activities of daily living, reading, and scanning ability. There was low-quality evidence of no significant increase in adverse events in people doing scanning training, as compared to no treatment.Three studies (166 participants) compared a substitutive intervention (a type of prism) with a control. There was low or very-low quality evidence that prisms did not have an effect on measures of activities of daily living, extended activities of daily living, reading, falls, or quality of life, and very low-quality evidence that they may have an effect on scanning ability (one study, 39 participants, MD 9.80, 95% CI 1.91 to 17.69). There was low-quality evidence of an increased odds of an adverse event (primarily headache) in people wearing prisms, as compared to no treatment.One study (39 participants) compared the effect of assessment by an orthoptist to standard care (no assessment) and found very low-quality evidence that there was no effect on measures of activities of daily living.Due to the quality and quantity of evidence, we remain uncertain about the benefits of assessment interventions. AUTHORS' CONCLUSIONS:There is a lack of evidence relating to the effect of interventions on our primary outcome of functional ability in activities of daily living. There is limited low-quality evidence that compensatory scanning training may be more beneficial than placebo or control at improving quality of life, but not other outcomes. There is insufficient evidence to reach any generalised conclusions about the effect of restitutive interventions or substitutive interventions (prisms) as compared to placebo, control, or no treatment. There is low-quality evidence that prisms may cause minor adverse events