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1.
Crit Care ; 24(1): 66, 2020 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-32093710

RESUMO

BACKGROUND: Intensive care unit (ICU) delirium is a frequent secondary neurological complication in critically ill patients undergoing prolonged mechanical ventilation. Quantitative pupillometry is an emerging modality for the neuromonitoring of primary acute brain injury, but its potential utility in patients at risk of ICU delirium is unknown. METHODS: This was an observational cohort study of medical-surgical ICU patients, without acute or known primary brain injury, who underwent sedation and mechanical ventilation for at least 48 h. Starting at day 3, automated infrared pupillometry-blinded to ICU caregivers-was used for repeated measurement of the pupillary function, including quantitative pupillary light reflex (q-PLR, expressed as % pupil constriction to a standardized light stimulus) and constriction velocity (CV, mm/s). The relationship between delirium, using the CAM-ICU score, and quantitative pupillary variables was examined. RESULTS: A total of 59/100 patients had ICU delirium, diagnosed at a median 8 (5-13) days from admission. Compared to non-delirious patients, subjects with ICU delirium had lower values of q-PLR (25 [19-31] vs. 20 [15-28] %) and CV (2.5 [1.7-2.8] vs. 1.7 [1.4-2.4] mm/s) at day 3, and at all additional time-points tested (p < 0.05). After adjusting for the SOFA score and the cumulative dose of analgesia and sedation, lower q-PLR was associated with an increased risk of ICU delirium (OR 1.057 [1.007-1.113] at day 3; p = 0.03). CONCLUSIONS: Sustained abnormalities of quantitative pupillary variables at the early ICU phase correlate with delirium and precede clinical diagnosis by a median 5 days. These findings suggest a potential utility of quantitative pupillometry in sedated mechanically ventilated ICU patients at high risk of delirium.


Assuntos
Estado Terminal , Delírio , Pupila , Respiração Artificial , Idoso , Estudos de Coortes , Cuidados Críticos , Delírio/diagnóstico , Delírio/etiologia , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Pupila/fisiologia , Respiração Artificial/efeitos adversos
2.
PLoS One ; 15(1): e0224733, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31986151

RESUMO

SIGNIFICANCE: This is the first study to validate the repeatability of objective measurements of amplitude of accommodation (AA) using the TONOREF III (NIDEK Co., Ltd., Japan), which can measure the AA in 30 seconds. PURPOSE: To evaluate the repeatability of objective measurements of AA using the TONOREF III and explored the association between objectively measured AA and factors, including age, sex, spherical equivalent, baseline pupil size and pupil size change during accommodation. METHODS: This cross-sectional study recruited 35 healthy subjects aged 26 to 52 years. The Bland-Altman method and intraclass correlation coefficients (ICCs) were used to assess the repeatability of TONOREF III measurements. The relationships between AA and age, sex, baseline pupil size, changes in pupil size (ΔPS) during accommodation were analyzed using linear regression for univariate and multivariate analysis. RESULTS: The mean difference in AA (ΔAA) between two sessions of TONOREF III measurements was 0.23 D (95% CI: -1.07 to +1.53 D), while no significant correlation was found between the mean and ΔAA (p = .14). The ICCs of the TONOREF III was 0.96. Age, sex, and ΔPS during accommodation were significant factors affecting the AA in multivariate analysis. CONCLUSIONS: The repeatability of objective AA measurements using the TONOREF III was good. Measuring AA using the TONOREFTM III in clinical practice is feasible.


Assuntos
Acomodação Ocular/fisiologia , Optometria , Pupila/fisiologia , Refração Ocular/fisiologia , Adulto , Estudos Transversais , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
3.
Int J Radiat Oncol Biol Phys ; 106(2): 422-429, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31669563

RESUMO

PURPOSE: Patients have reported sensations of seeing light flashes during radiation therapy, even with their eyes closed. These observations have been attributed to either direct excitation of retinal pigments or generation of Cherenkov light inside the eye. Both in vivo human and ex vivo animal eye imaging was used to confirm light intensity and spectra to determine its origin and overall observability. METHODS AND MATERIALS: A time-gated and intensified camera was used to capture light exiting the eye of a patient undergoing stereotactic radiosurgery in real time, thereby verifying the detectability of light through the pupil. These data were compared with follow-up mechanistic imaging of ex vivo animal eyes with thin radiation beams to evaluate emission spectra and signal intensity variation with anatomic depth. Angular dependency of light emission from the eye was also measured. RESULTS: Patient imaging showed that light generation in the eye during radiation therapy can be captured with a signal-to-noise ratio of 68. Irradiation of ex vivo eye samples confirmed that the spectrum matched that of Cherenkov emission and that signal intensity was largely homogeneous throughout the entire eye, from the cornea to the retina, with a slight maximum near 10 mm depth. Observation of the signal external to the eye was possible through the pupil from 0° to 90°, with a detected emission near 2500 photons per millisecond (during peak emission of the ON cycle of the pulsed delivery), which is over 2 orders of magnitude higher than the visible detection threshold. CONCLUSIONS: By quantifying the spectra and magnitude of the signal, we now have direct experimental observations that Cherenkov light is generated in the eye during radiation therapy and can contribute to perceived light flashes. Furthermore, this technique can be used to further study and measure phosphenes in the radiation therapy clinic.


Assuntos
Luz , Fenômenos Fisiológicos Oculares/efeitos da radiação , Radiocirurgia , Razão Sinal-Ruído , Animais , Humanos , Neoplasias Meníngeas/radioterapia , Meningioma/radioterapia , Pupila/fisiologia , Suínos
4.
Curr Opin Ophthalmol ; 31(1): 33-42, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31743155

RESUMO

PURPOSE OF REVIEW: Cataract surgery is the most common surgical procedure performed worldwide. Small pupils have been an eternal challenge for cataract surgeons; insufficient pupil dilation is associated with increased complication rates, including capsule rupture, vitreous loss, iris trauma or postoperative inflammation. The aim of the current review is to present the methods for pupil dilation and the risk factors for a small pupil in a cataract patient. RECENT FINDINGS: Risk factors for intraoperative small pupil include diabetes, intraoperative floppy iris syndrome, pseudoexfoliation syndrome, receiving glaucoma medications, having undergone previous ocular surgery and iris sphincter sclerosis from aging. There is a wide range of options to manage the small pupil, including pharmacological treatment, mechanical stretching, dilation with iris hooks or pupil expanders. We recommend a stepwise approach for intraoperative pupil dilation, from pharmacological mydriasis to pupil expanders. SUMMARY: The current article discusses risk factors for a small pupil and the methods for pupil dilation in a cataract patient. Every cataract surgeon needs to be ready to cope with a small pupil, both manifesting preoperatively and intraoperatively.


Assuntos
Extração de Catarata , Miose/terapia , Pupila/fisiologia , Humanos , Miose/fisiopatologia , Oftalmologia/métodos , Fatores de Risco
5.
J Pediatr Ophthalmol Strabismus ; 56: e76-e78, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31821512

RESUMO

Ocular complications of adenotonsillectomy are rare. The authors describe a 6-year-old boy who developed mydrasis and limitations of supraduction and infraduction after adenotonsillectomy. This was attributed to the hemorrhagic compression of the nerve in the cavernous sinus. This is the first report of pupil-involving oculomotor nerve palsy following adenotonsillectomy. [J Pediatr Ophthalmol Strabismus. 2019;56:e76-e78.].


Assuntos
Adenoidectomia/efeitos adversos , Movimentos Oculares/fisiologia , Midríase/etiologia , Doenças do Nervo Oculomotor/etiologia , Nervo Oculomotor/fisiopatologia , Pupila/fisiologia , Tonsilectomia/efeitos adversos , Criança , Humanos , Imagem por Ressonância Magnética , Masculino , Midríase/diagnóstico , Midríase/fisiopatologia , Doenças do Nervo Oculomotor/diagnóstico , Doenças do Nervo Oculomotor/fisiopatologia , Complicações Pós-Operatórias
6.
PLoS One ; 14(12): e0226692, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31877152

RESUMO

Autonomous sensory meridian response (ASMR) is a sensory phenomenon commonly characterized by pleasant tingling sensations arising from the back of the head and accompanied by feelings of relaxation and calmness. Although research has found ASMR to have a distinct physiological pattern with increased skin conductance levels and reduced heart rate, the specific tingles felt in ASMR have not received much investigation. The aim of the present study was to investigate the physiology and characteristics of ASMR further by examining whether experiencing ASMR is visible from the pupil of the eye. A total of 91 participants were recruited and assigned to three different groups based on their experience of ASMR (ASMR vs. non-ASMR vs. unsure). Participants were instructed to watch a control video and an ASMR video and to report any tingling sensations by pressing down a button on the keyboard. Pupil diameter was measured over the duration of both videos using a tower-mounted eye tracker. Data was analyzed on a general level, averaging pupil diameter over each video, as well as on a more specific level, comparing pupil diameter during reported episodes of tingling sensations to pupil diameter outside of those episodes. On the general level, results revealed no significant differences between the groups. On the specific level, however, the tingling sensations experienced in ASMR were found to cause statistically significant increases in pupil diameter, demonstrating that they have a physiological basis. The results of the study further reinforce the credibility of ASMR and suggest that the tingles felt in ASMR are at the very core of the experience itself.


Assuntos
Pupila/fisiologia , Campos Visuais , Adulto , Emoções , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fenômenos Fisiológicos Oculares , Óptica e Fotônica , Sensação , Fenômenos Fisiológicos da Pele , Adulto Jovem
8.
Invest Ophthalmol Vis Sci ; 60(13): 4303-4309, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31618767

RESUMO

Purpose: To investigate specific effects of denervation and stimulation of the internal carotid nerve (ICN) on the choroid and retina. Methods: Female Sprague Dawley rats underwent unilateral ICN transection (n = 20) or acute ICN electrical stimulation (n = 7). Rats in the denervation group were euthanized 6 weeks after nerve transection, and eyes were analyzed for changes in choroidal vascularity (via histomorphometry) or angiogenic growth factors and inflammatory markers (via ELISA). Rats in the stimulation group received acute ICN electrical stimulation with a bipolar cuff electrode over a range of stimulus amplitudes, frequencies, and pulse widths. Choroidal blood flow and pupil diameter were monitored before, during, and after stimulation. Results: Six weeks after unilateral ICN transection, sympathectomized choroids exhibited increased vascularity, defined as the percentage of choroidal surface area occupied by blood vessel lumina. Vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2) protein levels in denervated choroids were 61% and 124% higher than in contralateral choroids, respectively. TNF-α levels in denervated retinas increased by 3.3-fold relative to levels in contralateral retinas. In animals undergoing acute ICN electrical stimulation, mydriasis and reduced choroidal blood flow were observed in the ipsilateral eye. The magnitude of the reduction in blood flow correlated positively with stimulus frequency. Conclusions: Modulation of ICN activity reveals a potential role of the ocular sympathetic system in regulating endpoints related to neovascular diseases of the eye.


Assuntos
Artéria Carótida Interna/inervação , Corioide/irrigação sanguínea , Simpatectomia , Sistema Nervoso Simpático/cirurgia , Animais , Biomarcadores/metabolismo , Corioide/metabolismo , Estimulação Elétrica , Ensaio de Imunoadsorção Enzimática , Feminino , Pupila/fisiologia , Ratos , Ratos Sprague-Dawley , Retina/metabolismo , Gânglio Cervical Superior/fisiologia , Sistema Nervoso Simpático/fisiologia , Fator de Necrose Tumoral alfa/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
9.
Nat Neurosci ; 22(12): 2066-2077, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31659343

RESUMO

When learning the value of actions in volatile environments, humans often make seemingly irrational decisions that fail to maximize expected value. We reasoned that these 'non-greedy' decisions, instead of reflecting information seeking during choice, may be caused by computational noise in the learning of action values. Here using reinforcement learning models of behavior and multimodal neurophysiological data, we show that the majority of non-greedy decisions stem from this learning noise. The trial-to-trial variability of sequential learning steps and their impact on behavior could be predicted both by blood oxygen level-dependent responses to obtained rewards in the dorsal anterior cingulate cortex and by phasic pupillary dilation, suggestive of neuromodulatory fluctuations driven by the locus coeruleus-norepinephrine system. Together, these findings indicate that most behavioral variability, rather than reflecting human exploration, is due to the limited computational precision of reward-guided learning.


Assuntos
Tomada de Decisões/fisiologia , Aprendizagem/fisiologia , Recompensa , Adulto , Comportamento de Escolha/fisiologia , Feminino , Lobo Frontal/fisiologia , Humanos , Imagem por Ressonância Magnética , Masculino , Modelos Neurológicos , Neuroimagem , Pupila/fisiologia , Adulto Jovem
10.
Postgrad Med ; 131(7): 539-545, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31482757

RESUMO

Objectives: Cardiac autonomic nervous system (ANS) dysfunction is a common feature in patients receiving hemodialysis (HD) therapy, whilst is associated with an increased risk of ventricular arrhythmias and sudden cardiac death. The aim of this study is to investigate and compare the hemodynamic changes and responses of ANS function in HD patients using pupillometry and Heart Rate Variability (HRV) parameters. Methods: Sixteen chronic kidney diseases (CKD) patients receiving HD (52.18 ± 17.7 years) underwent both pupillometric measurements using a portable handheld pupil-measuring device and standard HRV analysis pre HD, every hour and 30 min post-HD session under two different scenarios: at rest while the patient resting at HD bed and when the patient performed a single bout of intradialytic aerobic exercise lasting for 45 min during the second hour of the HD therapy. Results: No significant changes in ANS values were observed in neither of the pupillometric and the HRV values pre HD, for each hour and post-HD session. HRV parameters were significantly correlated with pupillometric parameters at pre HD and immediately after the single bout of intradialytic exercise. ANS activity did not differ during the conventional HD session and during the session included intradialytic exercise. Moreover, sympatho-vagal balance indices deriving from pupillometric assessment showed beneficial changes after the exercise event. Conclusion: Pupillometry is a promising and robust technique with fewer artifacts compared to HRV especially in studies involving exercise sessions. Thus, pupillometry can be used as a complementary tool in the evaluation of cardiac autonomic dysfunction.


Assuntos
Doenças do Sistema Nervoso Autônomo/fisiopatologia , Exercício/fisiologia , Frequência Cardíaca/fisiologia , Pupila/fisiologia , Diálise Renal , Insuficiência Renal Crônica/terapia , Adulto , Idoso , Sistema Nervoso Autônomo/fisiopatologia , Humanos , Pessoa de Meia-Idade , Insuficiência Renal Crônica/fisiopatologia
11.
Invest Ophthalmol Vis Sci ; 60(12): 4021-4032, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31560767

RESUMO

Purpose: Connexins and aquaporins play essential roles in maintaining lens homeostasis and transparency and there is a close physical and functional relationship between these two proteins. Aquaporin 0 (AQP0), in addition to its role in water transport in the lens, acts as a cell-cell adhesion molecule. Recently, we showed a new role of connexin (Cx) 50 in mediating cell-cell adhesion. However, the cooperative roles of these two proteins in the lens in vivo have not been reported. Methods: We generated an AQP0/Cx50 double knockout (dKO) mouse model. Light, fluorescence, transmission thin section, and freeze-fracture electron microscopy, as well as wheat germ agglutinin and phalloidin labeling were used to evaluate lens structure. Mechanical properties of lenses were determined by mechanical compression testing. Results: DKO mice exhibited small eyes and lenses with severe cataracts, along with lens posterior defects, including posterior capsule rupture. The dKO mouse lenses had severe structural disruption associated with increased spaces between lens fiber cells when compared with wild-type lenses or lenses deficient in either Cx50 or AQP0. DKO mice also exhibited greater reduction in lens size compared with Cx50 KO mice. Gap-junction plaque size was greatly decreased in cortical fiber cells in dKO mice. Moreover, lens stiffness and elasticity were completely diminished, exhibiting a gelatinous texture in adult dKO mice. Conclusions: This novel mouse model reveals that Cx50 and AQP0 play an important role in mediating cell-cell adhesion function in the lens fiber cells and their deficiency impairs lens fiber organization, integrity, mechanical properties, and lens development.


Assuntos
Aquaporinas/fisiologia , Catarata/metabolismo , Conexinas/fisiologia , Anormalidades do Olho/metabolismo , Proteínas do Olho/fisiologia , Cristalino/metabolismo , Animais , Catarata/patologia , Adesão Celular/fisiologia , Anormalidades do Olho/patologia , Feminino , Técnica de Fratura por Congelamento , Cristalino/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Pupila/fisiologia
12.
Nat Commun ; 10(1): 4030, 2019 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-31492881

RESUMO

The ability to track the statistics of our surroundings is a key computational challenge. A prominent theory proposes that the brain monitors for unexpected uncertainty - events which deviate substantially from model predictions, indicating model failure. Norepinephrine is thought to play a key role in this process by serving as an interrupt signal, initiating model-resetting. However, evidence is from paradigms where participants actively monitored stimulus statistics. To determine whether Norepinephrine routinely reports the statistical structure of our surroundings, even when not behaviourally relevant, we used rapid tone-pip sequences that contained salient pattern-changes associated with abrupt structural violations vs. emergence of regular structure. Phasic pupil dilations (PDR) were monitored to assess Norepinephrine. We reveal a remarkable specificity: When not behaviourally relevant, only abrupt structural violations evoke a PDR. The results demonstrate that Norepinephrine tracks unexpected uncertainty on rapid time scales relevant to sensory signals.


Assuntos
Nível de Alerta/fisiologia , Potenciais Evocados Auditivos/fisiologia , Desempenho Psicomotor/fisiologia , Pupila/fisiologia , Tempo de Reação/fisiologia , Som , Estimulação Acústica , Adulto , Encéfalo/metabolismo , Encéfalo/fisiologia , Feminino , Humanos , Masculino , Norepinefrina/metabolismo , Incerteza , Adulto Jovem
13.
J Vis ; 19(9): 5, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31415056

RESUMO

The size of the pupil depends on light level. Watson and Yellott (2012) developed a unified formula to predict pupil size from luminance, field diameter, age, and number of eyes. Luminance reflects input from the L and M cones in the retina but ignores the contribution of intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing the photopigment melanopsin, which are known to control the size of the pupil. We discuss the role of melanopsin in controlling pupil size by reanalyzing an extant data set (Bouma, 1962). We confirm that melanopsin-weighted quantities, in conjunction with Watson and Yellott's formula, adequately model intensity-dependent pupil size. We discuss the contributions of other photoreceptors into pupil control.


Assuntos
Pupila/fisiologia , Células Fotorreceptoras Retinianas Cones/fisiologia , Animais , Humanos , Estimulação Luminosa , Células Ganglionares da Retina/fisiologia , Opsinas de Bastonetes/metabolismo
14.
J Fr Ophtalmol ; 42(8): e339-e348, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31439408

RESUMO

INTRODUCTION: Cataract surgery is the most commonly performed surgery in the world, and its success depends in part on the quality of mydriasis. PURPOSE: To compare, for the same eye, the pupillary dilation obtained with Mydrane® (standardized intracameral solution of 0.02% tropicamide, combined with 0.31% phenylephrine and 1% lidocaine) intraoperatively versus Mydriasert® (0.28mg tropicamide insert and 5.4mg phenylephrine) with a contact time between 45 and 60 minutes in the preoperative period. METHODS: Single center prospective study from November 2016 to January 2018 at the Laveran Army Instructional Hospital in Marseille. Patients referred for surgery were dilated at the preoperative consultation with Mydriasert®. The pupillary diameter after 45-60 minutes of contact with the insert was manually measured, by two different examiners, through the "iris image" tab of the Pentacam® elevation topography. Patients were dilated on the day of their cataract surgery with 0.2cc of Mydrane® injected in the anterior chamber through a paracentesis. Thirty seconds later, prior to injection of viscoelastic, an eye photograph was taken by screen capture. The pupillary diameter was evaluated by two different examiners with to the Piximeter 5.9 metrology software. The difference in pupil dilation between Mydriasert® and Mydrane® was tested with the paired series Student t-test. RESULTS: A hundred and eleven eyes of 82 patients were included. Mydriasert® achieved a mean pupillary dilation of 7.21±0.79mm. The mydriasis obtained with Mydrane® averaged 6.35±0.8mm. This difference of 0.86mm was statistically significant (P<0.001) with a confidence interval of 95% [-0.97; -0.74]. CONCLUSION: On average, Mydrane® dilates the pupil less than Mydriasert®. However, the mydriasis obtained with Mydrane® remains comfortable for the performance of the capsulorhexis. It helps save preoperative time and affords additional anesthetic to the cataract surgery. Nevertheless, the use of Mydriasert® is beneficial when extra mydriasis is required.


Assuntos
Extração de Catarata/métodos , Midriáticos/administração & dosagem , Pupila/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Extração de Catarata/normas , Dilatação , Esquema de Medicação , Combinação de Medicamentos , Feminino , Humanos , Período Intraoperatório , Masculino , Pessoa de Meia-Idade , Soluções Oftálmicas , Período Pré-Operatório , Pupila/fisiologia , Padrão de Cuidado
15.
Asia Pac J Ophthalmol (Phila) ; 8(4): 304-307, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31385819

RESUMO

PURPOSE: The aim of this study was to evaluate the factors affecting cycloplegia, as determined by pupil reactivity, in Asian children. DESIGN: Prospective observational study. METHODS: Two-hundred sixty-eight children, aged 2 to 12 years, requiring cycloplegic refraction, were recruited. Nurses instilled 2 to 3 cycles of eye drops consisting of cyclopentolate 1%, tropicamide 0.5%, and phenylephrine 2.5%, and recorded the child's level of cooperation. Optometrists recorded pupil reactivity after the last cycle. Multivariate analysis determined factors affecting pupil reactivity including age, sex, race, number of eye drop cycles, pupil sizes before and after cycloplegia, and child's cooperation during eye drops instillation. RESULTS: The pupils in 36 children (13.4%) were found to be still reactive. On univariate analysis, children with reactive pupils also had smaller pupils after cycloplegia (6.27 ±â€Š1.16 mm vs 7.42 ±â€Š0.81 mm, P < 0.001). On multiple logistic regression analysis, for every 1-mm increase in the pupil size after cycloplegic eye drop administration, the odds of having reactive pupils decreases by 65% (odds ratio = 0.35, 95% confidence interval 0.25-0.51, P ≤ 0.001). Those who were uncooperative during administration of eye drops were 3.13 times more likely to have reactive pupils (95% confidence interval 1.21-8.13, P = 0.019), whereas age (P = 0.904), sex (P = 0.355), the number of cycles of eye drops (P = 0.462), and other psychological factors were not relevant in affecting pupil reactivity. CONCLUSIONS: Pupil reactivity, which was used as a measure of cycloplegia, was more likely to be affected by children's level of cooperation during instillation of eye drops, rather than age and sex. Two cycles of eye drops were as effective as 3 cycles in producing cycloplegia.


Assuntos
Acomodação Ocular/efeitos dos fármacos , Ciclopentolato/administração & dosagem , Fenilefrina/administração & dosagem , Pupila/fisiologia , Refração Ocular/fisiologia , Tropicamida/administração & dosagem , Criança , Pré-Escolar , China , Feminino , Humanos , Masculino , Midriáticos/administração & dosagem , Soluções Oftálmicas , Estudos Prospectivos , Pupila/efeitos dos fármacos
16.
Acta Psychol (Amst) ; 198: 102882, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31288107

RESUMO

We hypothesized that pupil constrictions to the glare illusion, where converging luminance gradients subjectively enhance the perception of brightness, would be stronger for 'blue' than for other colors. Such an expectation was based on reflections about the ecology of vision, where the experience of dazzling light is common when one happens to look directly at sunlight through some occluders. Thus, we hypothesized that pupil constrictions to 'blue' reflect an ecologically-based expectation of the visual system from the experience of sky's light and color, which also leads to interpret the blue gradients of illusory glare to act as effective cues to impending probable intense light. We therefore manipulated the gradients color of glare illusions and measured changes in subjective brightness of identical shape stimuli. We confirmed that the blue resulted in what was subjectively evaluated as the brightest condition, despite all colored stimuli were equiluminant. This enhanced brightness effect was observed both in a psychophysical adjustment task and in changes in pupil size, where the maximum pupil constriction peak was observed with the 'blue' converging gradients over and above to the pupil response to blue in other conditions (i.e., diverging gradients and homogeneous patches). Moreover, glare-related pupil constrictions for each participant were correlated to each individual's subjective brightness adjustments. Homogenous blue hues also constricted the pupil more than other hues, which represents a pupillometric analog of the Helmholtz-Kohlrausch effect on brightness perception. Together, these findings show that pupillometry constitutes an easy tool to assess individual differences in color brightness perception.


Assuntos
Percepção de Cores/fisiologia , Cor , Ofuscação , Ilusões/fisiologia , Estimulação Luminosa/métodos , Pupila/fisiologia , Adulto , Sinais (Psicologia) , Feminino , Humanos , Individualidade , Masculino , Percepção Visual/fisiologia , Adulto Jovem
17.
PLoS Comput Biol ; 15(7): e1007126, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31276488

RESUMO

Living creatures must accurately infer the nature of their environments. They do this despite being confronted by stochastic and context sensitive contingencies-and so must constantly update their beliefs regarding their uncertainty about what might come next. In this work, we examine how we deal with uncertainty that evolves over time. This prospective uncertainty (or imprecision) is referred to as volatility and has previously been linked to noradrenergic signals that originate in the locus coeruleus. Using pupillary dilatation as a measure of central noradrenergic signalling, we tested the hypothesis that changes in pupil diameter reflect inferences humans make about environmental volatility. To do so, we collected pupillometry data from participants presented with a stream of numbers. We generated these numbers from a process with varying degrees of volatility. By measuring pupillary dilatation in response to these stimuli-and simulating the inferences made by an ideal Bayesian observer of the same stimuli-we demonstrate that humans update their beliefs about environmental contingencies in a Bayes optimal way. We show this by comparing general linear (convolution) models that formalised competing hypotheses about the causes of pupillary changes. We found greater evidence for models that included Bayes optimal estimates of volatility than those without. We additionally explore the interaction between different causes of pupil dilation and suggest a quantitative approach to characterising a person's prior beliefs about volatility.


Assuntos
Modelos Biológicos , Pupila/fisiologia , Acetilcolina/fisiologia , Adolescente , Adulto , Teorema de Bayes , Biologia Computacional , Simulação por Computador , Tomada de Decisões , Meio Ambiente , Humanos , Locus Cerúleo/fisiologia , Cadeias de Markov , Modelos Neurológicos , Norepinefrina/fisiologia , Transdução de Sinais , Incerteza , Adulto Jovem
18.
J Abnorm Psychol ; 128(6): 622-632, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31318244

RESUMO

Psychopathy is characteristically associated with impairments in recognizing others' facial expressions of emotion, and there is some evidence that these difficulties are specific to the callousness features of the disorder. However, it remains unclear whether these difficulties are accompanied by reductions in autonomic reactivity when viewing others' emotional expressions, and whether these impairments are particular to expressions showing another's distress or are more pervasive across different emotional expressions. In this study, 73 adult male prisoners with histories of serious sexual or violent offenses-who ranged across the psychopathy continuum-completed a facial emotion recognition task. For the first time in a convicted offender sample, we used pupillometry techniques to measure changes in the pupil dilation response, a measure of sympathetic autonomic arousal to affective stimuli. We found that the callousness features of psychopathy were related to impaired recognition of fearful faces. Strikingly, we also showed that increasing callousness was associated with a reduction in the pupil dilation response and that this was pervasive across different emotional expressions. Our results highlight a potential role of the locus coeruleus-noradrenaline system in the pathophysiology of psychopathy and demonstrate the potential of the pupillary response as a technique for understanding attention-emotion interactions in psychopathy. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Transtorno da Personalidade Antissocial/fisiopatologia , Criminosos , Expressão Facial , Reconhecimento Facial/fisiologia , Medo/fisiologia , Pupila/fisiologia , Percepção Social , Violência , Adulto , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Prisioneiros , Adulto Jovem
19.
Optom Vis Sci ; 96(8): 587-598, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31318801

RESUMO

SIGNIFICANCE: This study highlights potential differences that can arise in gaze-position estimates from first Purkinje image-based eye trackers based on how individual Hirschberg ratios (HRs) are calculated. PURPOSE: The purpose of this study was to evaluate the accuracy and repeatability of eccentric-viewing, prism-based, and theoretical techniques that are routinely used to calibrate HR in first Purkinje image-based eye trackers. METHODS: Hirschberg ratios of 28 participants (18 to 40 years old) were obtained using the PlusOptix PowerRef 3 photorefractor and eye tracker. In the gold standard eccentric-viewing technique, participants viewed eccentric targets (±12°, 4° steps) at 2 m. In the prism-based technique, 4 to 16Δ-D base-out and base-in prisms were placed in 4Δ-D steps before an eye occluded with an infrared filter; the fellow eye fixated a target at 1 m. Each participant's HR was calculated as the slope of the linear regression of the shift in Purkinje image relative to the pupil center for each target eccentricity or induced prism power. Theoretical HR was calculated from the participant's corneal curvature and anterior chamber depth measures. Data collection was repeated on another visit using all three techniques to assess repeatability. Data were also obtained from an Indian cohort (n = 30, 18 to 40 years old) using similar protocols. RESULTS: Hirschberg ratio ranged from 10.61 to 14.63°/mm (median, 11.90°/mm) in the eccentric-viewing technique. The prism-based and theoretical techniques demonstrated inaccuracies of 12 and 4% relative to the eccentric-viewing technique. The 95% limits of agreement of intrasubject variability were ±2.00, ±0.40, and ±0.30°/mm for the prism-based, eccentric-viewing, and theoretical techniques, respectively (P > .05). Intraclass correlation coefficients (95% confidence interval) were 0.99 (0.98 to 1.00) for eccentric, 0.99 (0.99 to 1.00) for theoretical, and 0.88 (0.74 to 0.94) for prism-based techniques. Similar results were found for the Indian cohort. CONCLUSIONS: The prism-based and theoretical techniques both demonstrated relative inaccuracies in measures of HR compared with the eccentric-viewing technique. The prism-based technique exhibited the poorest repeatability.


Assuntos
Movimentos Oculares/fisiologia , Fixação Ocular/fisiologia , Fotogrametria/normas , Gravação em Vídeo/normas , Adolescente , Adulto , Calibragem , Feminino , Humanos , Masculino , Pupila/fisiologia , Reprodutibilidade dos Testes , Adulto Jovem
20.
J Binocul Vis Ocul Motil ; 69(3): 102-105, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31329052

RESUMO

The pupillary exam in the pediatric population is a vital part of any clinician's workup. In the right clinical setting, pupillary abnormalities such as anisocoria, light-near dissociation, an afferent pupillary defect, and paradoxic pupillary constriction in the dark can be red flags that trigger further examination and workup. Through both careful physical examination and detailed history-taking and observation, potentially vision- and life-threatening conditions can be detected.


Assuntos
Exame Físico , Distúrbios Pupilares/diagnóstico , Criança , Pré-Escolar , Feminino , Síndrome de Horner/diagnóstico , Humanos , Masculino , Transtornos da Motilidade Ocular/diagnóstico , Doenças do Nervo Oculomotor/diagnóstico , Pupila/fisiologia , Distúrbios Pupilares/fisiopatologia , Reflexo Pupilar/fisiologia
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