Pupillary Dilation
Recently Published Documents


TOTAL DOCUMENTS

197
(FIVE YEARS 50)

H-INDEX

23
(FIVE YEARS 4)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yudai Takarada ◽  
Daichi Nozaki

AbstractPrevious research has demonstrated that human maximal voluntary force is generally limited by neural inhibition. Producing a shout during maximal exertion effort enhances the force levels of maximal voluntary contraction. However, the mechanisms underlying this enhancement effect on force production remain unclear. We investigated the influence of producing a shout on the pupil-linked neuromodulatory system state by examining pupil size. We also examined its effects on the motor system state by examining motor evoked potentials in response to transcranial magnetic stimulation applied over the contralateral primary motor cortex, and by evaluating handgrip maximal voluntary force. Analysis revealed that producing a shout significantly increased handgrip maximal voluntary force, followed by an increase in pupil size and a reduction of the cortical silent period. Our results indicate that producing a shout increased handgrip maximal voluntary force through the enhancement of motor cortical excitability, possibly via the enhancement of noradrenergic system activity. This study provides evidence that the muscular force-enhancing effect of shouting during maximal force exertion is related to both the motor system state and the pupil-linked neuromodulatory system state.


2021 ◽  
Author(s):  
Yolanda Lopez de Audicana Jimenez de Abera ◽  
Ana Vallejo De la Cueva ◽  
Nerea Aretxabala Cortajarena ◽  
Amaia Quintano Rodero ◽  
Cesar Rodriguez Nuñez ◽  
...  

Abstract Background: Pain continues to be an underdiagnosed problem. Objective tools are needed for its assessment. The objective of this study was to determine the diagnostic performance, validity and reliability of the pupillary dilation reflex (PDR) against the Behavioural Pain Scale (BPS) to assess pain in patients under light-moderate sedation.Methods: A study of diagnostic tests using PDR versus BPS as a reference test was performed. The patients were recruited from the Intensive Care Units of the Araba University Hospital and were consecutively admitted. They were older than 18 years, under intravenous analgosedation, mechanically ventilated and had a BPS score of three and a Richmond Agitation and Sedation Scale (RASS) score between -1 and -4. The responses to a non-painful (NP) stimulus, 10 mA, 20 mA, 30 mA and 40 mA stimuli, and was assessed with the BPS and PDR. PDR measurements were performed with an Algican® pupilometer. Pain was considered to be present at BPS≥4. The receiver operating curve (ROC) was plotted, and the area under the curve (AUC) was calculated. We identified the cut-off points showing the highest sensitivity and specificity. Diagnostic performance was studied based on the Youden index, negative predictive value (NPV), positive predictive value (PPV), accuracy, positive likelihood ratio (PLR), and negative likelihood ratio (NPC) of each of them. They are presented with their 95% confidence intervals (CI). Results: Thirty-one patients were included and 183 measurements were performed. 49 (27%) measurements showed a painful response according to the BPS. We obtained an AUC of 0.885 (95% CI 0.830-0.940). The PDR value with the best diagnostic efficacy was 11.5%, which had a sensitivity of 89.8% (95% CI 78.2-95.6) and a specificity of 78.4% (95% CI 70.6-84.5) with an accuracy of 81.4 (75.2-86.4). The agreement between BPS and PDR had a kappa index of 0.6. Conclusions: Pupillometry could be a valid alternative for identifying pain in analgosedated critical patients. Trial registrationPhase 1 of the project PUPIPAIN ClinicalTrials.gov Identifier: NCT04078113


2021 ◽  
Vol 11 (9) ◽  
pp. 1194
Author(s):  
Joanna Sołek-Pastuszka ◽  
Małgorzata Zegan-Barańska ◽  
Jowita Biernawska ◽  
Marcin Sawicki ◽  
Waldemar Iwańczuk ◽  
...  

Background: During routine diagnosis of brain death, changes in pupil diameter in response to the stimulation of peripheral nerves are sometimes observed. For example, pupillary dilation after diagnosed brain death is described in the literature as the ciliospinal reflex. However, pupil constriction creates diagnostic doubts. Objective: The pupillometric analysis of pupil response to stimulation of the cervicothoracic spinal cord in patients with diagnosed brain death. Methods: Instrumental tests to confirm the arrest of cerebral circulation were performed in 30 adult subjects (mean age 53.5 years, range 26–75 years) with diagnosed brain death. In addition, a pupillometer was used to measure the change in pupil diameter in response to neck flexion. Intervention: Flexion of the neck and measuring the response in change of the pupil with the use of the pupillometer. Results: The change in the pupil was observed in the examined group of patients. Difference in pupil size ≥0.2 mm was observed in 14 cases (46%). In five cases (17%), pupil constriction was found (from 0.2 to 0.7 mm). Measurement error was +/− 0.1 mm. Conclusions: Both pupillary constriction and dilatation may occur due to a ciliospinal reflex in patients with brain death. This phenomenon needs further research in order to establish its pathophysiology.


2021 ◽  
pp. 112067212110443
Author(s):  
Ersin Muhafiz ◽  
Erdinç Bozkurt ◽  
Can Emre Erdoğan ◽  
Şerif Nizamoğulları ◽  
Mehmet Siraç Demir

Purpose: To examine the static and dynamic pupillary functions with automated pupillography in multiple sclerosis (MS) patients with preserved visual acuity. Methods: Forty-seven MS patients with preserved visual acuity were included in the study group and 43 healthy volunteers in the control group. The visual evoked potential of the patients was obtained. After routine ophthalmologic examination contrast sensitivity and the retinal nerve fiber layer (RNFL) thickness were measured. Finally scotopic, mesopic, and photopic pupillographies followed by dynamic pupillography were undertaken, and the pupillary dilatation speed was calculated. Results: The contrast sensitivity and RNFL thickness of the MS group were significantly lower than those of the control group ( p < 0.05; for both). In the MS and control groups, the scotopic pupil diameters were 5.48 ± 1.03 and 5.28 ± 0.78 mm, mesopic pupil diameters were 4.82 ± 0.83 and 4.48 ± 0.70 mm, and photopic pupil diameters were 3.84 ± 0.79 and 3.42 ± 0.49 mm, respectively ( p = 0.315, p = 0.044, and p = 0.004, respectively). In dynamic pupillography, the pupil in the MS group was more dilated than control group at all time sections examined except the sixth second ( p < 0.05; for all). Although the mean pupillary dilation speed in the first second was higher in the MS group ( p = 0.044), there was no significant difference between the groups for the other time intervals examined ( p > 0.05; for all). There was no correlation between pupillary parameters and P100-wave latency, RNFL thickness, or contrast sensitivity ( p > 0.05; for all). Conclusions: Static and dynamic pupillary functions may be affected in MS patients with preserved visual acuity. Although scotopic pupillary functions are preserved, mesopic, and photopic pupil functions are weakened.


2021 ◽  
Vol 10 (16) ◽  
pp. 3452
Author(s):  
Sze H. Wong ◽  
James C. Tsai

Telehealth has become a viable option for glaucoma screening and glaucoma monitoring due to advances in technology. The ability to measure intraocular pressure without an anesthetic and to take optic nerve photographs without pharmacologic pupillary dilation using portable equipment have allowed glaucoma screening programs to generate enough data for assessment. At home, patients can perform visual acuity testing, web-based visual field testing, rebound tonometry, and video visits with the physician to monitor for glaucomatous progression. Artificial intelligence will enhance the accuracy of data interpretation and inspire confidence in popularizing telehealth for glaucoma.


Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2553
Author(s):  
Pinakin Gunvant Davey ◽  
Richard B. Rosen ◽  
Dennis L. Gierhart

The study was designed to: (1) Analyze and create protocols of obtaining measurements using the Macular Pigment Reflectometry (MPR). (2) To assess the agreement of MPOD measurements obtained using the heterochromatic flicker photometry (MPS II) and MPR. (3) To obtain the lutein and zeaxanthin optical density obtained using the MPR in the central one-degree of the macula. The measurements were performed using the MPR and heterochromatic flicker photometry. The MPR measurements were performed twice without pupillary dilation and twice following pupillary dilation. The MPR measurements were performed for a 40-s period and the spectrometer signal was parsed at different time points: 10–20, 10–30, 10–40, 20–30, 20–40, and 30–40 s. The MPR analyzes the high-resolution spectrometer signal and calculates MPOD, lutein optical density and zeaxanthin optical density automatically. The MPR-MPOD data was compared with MPPS II-MPOD results. The MPR-MPOD values are highly correlated and in good agreement with the MPS II-MPOD. Of the various parsing of the data, the data 10–30 interval was the best at obtaining the MPOD, lutein, and zeaxanthin values (8–12% coefficient of repeatability). The lutein to zeaxanthin ratio in the central one-degree of the macula was 1:2.40. Dilation was not needed to obtain the MPOD values but provided better repeatability of lutein and zeaxanthin optical density. MPR generates MPOD measurements that is in good agreement with MPS II. The device can produce lutein and zeaxanthin optical density which is not available from other clinical devices.


2021 ◽  
Author(s):  
Yudai Takarada ◽  
Daichi Nozaki

Abstract Previous research has demonstrated that human maximal voluntary force is generally limited by neural inhibition. Indeed, producing a shout during maximal exertion efforts enhances the force levels of maximum voluntary contractions. However, the mechanisms underlying this enhancing effect of force production remain unknown. We investigated the influence of a shout on the pupil-linked neuromodulatory system state by examining pupil size. We also examined its effect on the motor system state by examining motor evoked potentials in response to transcranial magnetic stimulation applied over the contralateral primary motor cortex, and by evaluating the handgrip maximal voluntary force. Analysis showed that a shout significantly increased the handgrip maximal voluntary force, followed by an increase in pupil size and a reduction of the cortical silent period. Our results indicate that a shout can increase handgrip maximal voluntary force through the enhancement of motor cortical excitability, possibly via the enhancement of noradrenergic system activity. This study provides evidence that the muscular force-enhancing effect of a shout during maximal force exertion is related to both the motor system state and the pupil-linked neuromodulatory system state.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fang Fang ◽  
Jie Zhang ◽  
Pei Zhuang ◽  
Pingting Liu ◽  
Liang Li ◽  
...  

AbstractRecently, we established silicone oil-induced ocular hypertension (SOHU) mouse model with significant glaucomatous neurodegeneration. Here we characterize two additional variations of this model that simulate two distinct glaucoma types. The first is a chronic model produced by high frequency (HF) pupillary dilation after SO-induced pupillary block, which shows sustained moderate IOP elevation and corresponding slow, mild glaucomatous neurodegeneration. We also demonstrate that although SO removal quickly returns IOP to normal, the glaucomatous neurodegeneration continues to advance to a similar degree as in the HF group without SO removal. The second, an acute model created by no pupillary dilation (ND), shows a greatly elevated IOP and severe inner retina degeneration at an early time point. Therefore, by a straightforward dilation scheme, we extend our original SOHU model to recapitulate phenotypes of two major glaucoma forms, which will be invaluable for selecting neuroprotectants and elucidating their molecular mechanisms.


2021 ◽  
pp. 112067212110065
Author(s):  
Savleen Kaur ◽  
Shagun Korla ◽  
Jagat Ram ◽  
Parul Chawla Gupta ◽  
Jaspreet Sukhija

Purpose: To assess the efficacy and safety of intracameral mydriatic and anesthetic combination for pupillary dilation in pediatric cataract surgery Methods: This prospective series included children <12 years, with visually significant unilateral or bilateral cataracts planned for cataract surgery with/without intraocular lens implantation. At the beginning of surgery, 0.025 ml of a combination of phenylephrine hydrochloride (0.31%), tropicamide (0.02%), and lidocaine hydrochloride (1%) was injected intracamerally. The efficacy of the combination was tested by achieving capsulorhexis and intraocular lens implantation without additional mydriatics. Results: We recruited 13 patients (16 eyes) with a mean age of 4.1 ± 3.9 years. The mean pupillary diameter changed increased from 1.92 to 5.68 mm after injection of one unit (0.025 ml) of drug ( p < 0.0001). There was a strong positive correlation of the pupillary dilation with axial length ( R = 0.86) and horizontal corneal diameter ( R = 0.81). Seventy-five percent patients had a pupillary diameter >6 mm and surgery could be completed successfully in all cases without additional mydriatics. In all cases, pupil dilated as the surgery progressed. No adverse event to the drug was noted. Conclusions: Intracameral mydriatic-anesthetic combination is an effective and safe way to obtain stable mydriasis in pediatric cataract surgery.


2021 ◽  
Vol 21 (1) ◽  
pp. 11
Author(s):  
Xiaofei Hu ◽  
Rumi Hisakata ◽  
Hirohiko Kaneko
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document