Changes In Pupil Diameter Research Articles

Jacobi-Fourier phase masks as ophthalmic elements to correct presbyopia.

Investigations into the correction of presbyopia have considered lens design, clinical implications and the development of objective metrics such as the visual Strehl ratio. This study investigated the Jacobi-Fourier phase mask as an ophthalmic element in the correction of presbyopia. The goal was to develop a contact or intraocular lens whose performance was largely insensitive to changes in pupil diameter. Numerical simulations based on Fourier optics were performed to evaluate three different Jacobi-Fourier polynomials, with the aim of providing a range of clear vision (1 Dioptre (D)). Performance was evaluated for three pupil sizes (6, 4 and 2 mm), while polychromatic images were simulated using three different wavelengths (656.3, 587.6 and 486.1 nm). The Neural Transfer function was included in the simulation. To validate the method and results, we used the Visual Strehl combined objective metric (VSCombined) currently used in visual optics. This metric gives more weight to the phase transfer function and is more suitable for non-symmetrical phase functions. Numerical validation showed the suitability of the Jacobi-Fourier phase masks for extending the range of clear vision of presbyopic eyes, providing a visual acuity of at least 0.10 logMAR (6/7.5 Snellen) at all distances between 1 and 6 m. The results show a range of clear vision of 1D was not affected by changes in pupil size, an increase in retinal image contrast accompanied by image artefact reduction by increasing the radial order of the Jacobi-Fourier phase mask and a reduction of wavelength dependence of the retinal images. These results are supported by simulated images and the objective criterion VSCombined. The use of Jacobi-Fourier phase masks as ophthalmic elements for presbyopic correction show promising results, with a good range of clear vision andreduced dependence on pupil size and chromatic aberration.

Pupil old/new effect as an objective measure of recognition memory: a meta-analysis of 17 eye-tracking experiments

ABSTRACT Recognition memory, the ability to recognise previously encountered information, correlates with pupil diameter changes during the recognition period. This physiological response, known as the pupil old/new effect, generally reflects the variation in pupil dilation when encountering previously studied (old) stimuli compared to new stimuli. To develop a more precise understanding of the pupil old/new effect, we conducted a meta-analysis of 17 eye-tracking experiments (across 12 articles spanning from 2008 to 2023) involving 560 healthy adults with a mean age of 22.31 years. Analysis of publication bias showed a rather low risk of bias in the selected articles. The main meta-analysis revealed a significant and large pooled pupil old/new effect (Cohen’s dz = 0.73, 95% CI [0.50, 0.95]). Further analysis of moderators showed that the number of participants included in the experiments and the criteria for selecting trials (only correct trials vs. all trials) had a significant impact on the meta-analytic results. In general, the analyses revealed a robust pupil old/new effect across all selected articles. This finding underscores its potential utility as a marker of recognition memory across different stimuli type, and various experimental designs.

Pupillometry as a biomarker of postural control: Deep-learning models reveal side-specific pupillary responses to increased intensity of balance tasks.

Pupillometry has been used in the studies of postural control to assess cognitive load during dual tasks, but its response to increased balance task intensity has not been investigated. Furthermore, it is unknown whether side-specific changes in pupil diameter occur with more demanding balance tasks providing additional insights into postural control. The two aims of this study were to analyze differences in steady-state pupil diameter between balance tasks with increased intensity and to determine whether there are side-specific changes. Forty-eight healthy subjects performed parallel and left and right one-legged stances on a force plate with and without foam with right and left pupil diameters measured with a mobile infrared eye-tracker. Differences between balance tasks in parameters (average pupil diameter of each eye, average of both pupil diameters and the difference between the left and right pupil diameter) were analyzed using a two-way repeated measures analysis of variance, and deep learning neural network models were used to investigate how pupillometry predicted each balance task. The pupil diameter of the left eye, the average pupil diameter of both eyes and the difference in pupil diameters increased statistically significantly from simpler to more demanding balance tasks, with this being more pronounced for the left eye. The deep learning neural network models revealed side-specific changes in pupil diameter with more demanding balance tasks. This study confirms pupillary responses to increased intensity of balance task and indicates side-specific pupil responses that could be related to task-specific involvement of higher levels of postural control.

Smartphone pupillometry for detection of cerebral vasospasm after aneurysmal subarachnoid hemorrhage

ObjectivesVasospasm is a complication of aneurysmal subarachnoid hemorrhage (aSAH) that can change the trajectory of recovery and is associated with morbidity and mortality. Earlier detection of vasospasm could improve patient outcomes. Our objective is to evaluate the accuracy of smartphone-based quantitative pupillometry in the detection of radiographic vasospasm and delayed cerebral ischemia (DCI) after aSAH. Materials and MethodsWe prospectively collected pupillary light reflex (PLR) parameters from patients with aSAH admitted to a neurocritical care unit at a single hospital twice daily using quantitative smartphone pupillometry recordings. PLR parameters included: Maximum pupil diameter, minimum pupil diameter, percent change in pupil diameter, latency in beginning of pupil constriction to light, mean constriction velocity, maximum constriction velocity, and mean dilation velocity. Two-tailed t-tests for independent samples were performed to determine changes in average concurrent PLR parameter values between the following comparisons: (1) patients with and without radiographic vasospasm (defined by angiography with the need for endovascular intervention) and (2) patients with and without DCI. Results49 subjects with aSAH underwent 323 total PLR recordings. For PLR recordings taken with (n=35) and without (n=241) radiographic vasospasm, significant differences were observed in MIN (35.0 ± 7.5 pixels with vasospasm versus 31.6 ± 6.2 pixels without; p=0.002). For PLR recordings taken with (n=43) and without (n=241) DCI, significant differences were observed in MAX (48.9 ± 14.3 pixels with DCI versus 42.5 ± 9.2 pixels without; p<0.001). ConclusionsQuantitative smartphone pupillometry has the potential to be used to detect radiographic vasospasm and DCI after aSAH.

Changes in optic nerve sheath diameter and its correlation with degree of consciousness, pupil diameter, and light reflex in children with central nervous system infection after osmotherapy.

High intracranial pressure (ICP) is one of the most common complications of central nervous system (CNS) infection. Failure to control high intracranial pressure results in brain herniation and death. One of the treatments for high ICP involves the administration of osmotherapy in the form of 3% NaCl or 20% mannitol with observation during administration. Observation of ICP during administration of osmotherapy is possible through measurement of optic nerve sheath diameter (ONSD), which could be correlated with degree of consciousness, pupil diameter, and light reflex. Previous studies have not correlated ONSD with degree of consciousness, pupil diameter, and light reflex during the administration of osmotherapy. To provide insights of incorporating ONSD measurement as a form of non-invasive bedside method for ICP monitoring by correlating it with degree of consciousness, pupil diameter, and light reflex at several time points. This study is a prospective cohort study, performed at Dr. Hasan Sadikin General Central Hospital Bandung, Cibabat General Regional Hospital, and General Regional Hospital Bandung Kiwari on children aged 2-18 years with decreased consciousness and CNS infection, from June 2023. Inter-rater reliability was performed with a correlation coefficient of 0.90. Measurement of ONSD, degree of consciousness, pupil diameter, and light reflex simultaneously up to 48 h after initiation of osmotherapy to 30 patients. Correlational analyses were performed using Spearman's rank. Observation for 48 h after administration of osmotherapy showed changes in ONSD. A significant positive correlation was found between ONSD and degree of consciousness (r = 0.621 for the right eye and r = 0.602 for the left eye, p < 0.001). A significant positive correlation was found between ONSD and light reflex (r = 0.801 for the right eye and r = 0.812 for the left eye, p < 0.001). No significant correlation was found with changes of pupil diameter (r = -0.136 for the right eye and r = -0.141 for the left eye, p > 0.05). A significant correlation was found between ONSD and degree of consciousness and light reflex in children aged 2-18 years with CNS infection during administration of osmotherapy.

Intrasubject Variability in Intravenous and Oral Probes for Hepatic and First-Pass CYP3A Activity.

Clearances and the area under the plasma concentration-time curve extrapolated to infinity (AUC0-∞) of intravenous (IV) and oral midazolam and alfentanil are probes for hepatic and first-pass cytochrome P450 3A (CYP3A) activity, drug interactions, and phenotyping. Single-time plasma concentrations are also used as a proxy for clearance and AUC0-∞. Pupil diameter change is a noninvasive surrogate for plasma alfentanil. An ideal probe should have minimal intrasubject (interday) variability. Despite their widespread use, the intrasubject variability of CYP3A probes is not well characterized. This investigation determined the intrasubject (interday) variability of midazolam and alfentanil metrics of hepatic and first-pass CYP3A. Twelve volunteers were studied in a four-period protocol, with each period identical and separated by approximately 2 weeks. In each period, participants received 1 mg IV midazolam then 15 μg/kg IV alfentanil 1 h later. The next day, they received 3 mg oral midazolam then 60 μg/kg oral alfentanil. Plasma drug concentrations were determined by liquid chromatography-mass spectrometry (LCMS). Dark-adapted pupil diameters were measured coincident with blood sampling. Plasma concentrations and pupil effects (miosis) were analyzed using noncompartmental methods. The results were the coefficient of variation (%CV, mean ± SD) across four sessions in 12 participants. For IV midazolam: AUC0-∞, clearance, and 5 h concentration, the %CVs were 12 ± 3, 12 ± 3, and 18 ± 8. For IV alfentanil AUC0-∞, clearance, 2 h concentration, and area under the effect curve from time zero to infinity (AUEC0-∞), the %CVs were 16 ± 5, 15 ± 4, 22 ± 7, and 50 ± 28. For oral midazolam AUC0-∞, clearance, and 5 h concentration, %CVs were 19 ± 5, 18 ± 4, and 28 ± 11. For oral alfentanil: AUC0-∞, clearance, 4 h concentration, and AUEC0-∞, %CVs were 20 ± 4, 21 ± 4, 42 ± 26, and 37 ± 14. Midazolam and alfentanil had comparable intrasubject variabilities of clearance and AUC0-∞. Single-time point metrics had greater intrasubject variability than AUC0-∞ and clearance. Miosis was a surrogate for alfentanil concentrations and provided real-time results, but intrasubject variability was greater than that of clearances and AUC0-∞.

Widefield in vivo imaging system with two fluorescence and two reflectance channels, a single sCMOS detector, and shielded illumination.

Widefield microscopy of the entire dorsal part of mouse cerebral cortex enables large-scale ("mesoscopic") imaging of different aspects of neuronal activity with spectrally compatible fluorescent indicators as well as hemodynamics via oxy- and deoxyhemoglobin absorption. Versatile and cost-effective imaging systems are needed for large-scale, color-multiplexed imaging of multiple fluorescent and intrinsic contrasts. We aim to develop a system for mesoscopic imaging of two fluorescent and two reflectance channels. Excitation of red and green fluorescence is achieved through epi-illumination. Hemoglobin absorption imaging is achieved using 525- and 625-nm light-emitting diodes positioned around the objective lens. An aluminum hemisphere placed between objective and cranial window provides diffuse illumination of the brain. Signals are recorded sequentially by a single sCMOS detector. We demonstrate the performance of our imaging system by recording large-scale spontaneous and stimulus-evoked neuronal, cholinergic, and hemodynamic activity in awake, head-fixed mice with a curved "crystal skull" window expressing the red calcium indicator jRGECO1a and the green acetylcholine sensor . Shielding of illumination light through the aluminum hemisphere enables concurrent recording of pupil diameter changes. Our widefield microscope design with a single camera can be used to acquire multiple aspects of brain physiology and is compatible with behavioral readouts of pupil diameter.

Mydriasis in eastern box turtles (Terrapene carolina carolina) following topical administration of proparacaine, 10% phenylephrine, and rocuronium bromide.

To determine the mydriatic effect of topical 10% phenylephrine with 10 mg/mL rocuronium bromide and compare this protocol with and without pretreatment with proparacaine. Ten client-owned pet adult eastern box turtles (Terrapene carolina carolina). All turtles were sedated with 8 mg/kg alfaxalone intramuscularly. One group of four turtles received four 20 μL drops of 10% phenylephrine and four 20 μL drops of rocuronium bromide in the right eye. Another group of four turtles received one standard drop of proparacaine followed by four 20 μL drops of 10% phenylephrine and four 20 μL drops of rocuronium bromide in the right eye. Two control group turtles received four 20 μL drops of saline in the right eye. The left eye was untreated in all turtles. Drops of the same type were separated by 2 min while drops of different types were separated by 5 min. Pupil size was recorded at 0, 15, 30, 60, 90, 120, 180, 240, and 360 min after administration of the final drop. Treatment with 10% phenylephrine and rocuronium bromide resulted in pupil diameter changes from baseline that were statistically significant from zero at 60, 90, and 120 min in the non-proparacaine group and 90 min in the proparacaine group. The time to peak effect was 90 min in the proparacaine group and 75 min in the non-proparacaine group. Saline-treated pupils in the control group decreased in diameter over the study period. Overall, the treated eyes of the proparacaine group and non-proparacaine group were not different from each other, but both dilated more than the control group. Rocuronium bromide and 10% phenylephrine can produce effective and safe mydriasis in eastern box turtles, but there was wide interindividual variation in effectiveness. Proparacaine did not improve the mydriatic effect.

The other-race effect of pupil contagion in infancy

Pupil contagion refers to the observer’s pupil-diameter changes in response to changes in the pupil diameter of others. Recent studies on the other-race effect on pupil contagion have mainly focused on using eye region images as stimuli, revealing the effect in adults but not in infants. To address this research gap, the current study used whole-face images as stimuli to assess the pupil-diameter response of 5–6-month-old and 7–8-month-old infants to changes in the pupil-diameter of both upright and inverted unfamiliar-race faces. The study initially hypothesized that there would be no pupil contagion in either upright or inverted unfamiliar-race faces, based on our previous finding of pupil contagion occurring only in familiar-race faces among 5–6-month-old infants. Notably, the current results indicated that 5–6-month-old infants exhibited pupil contagion in both upright and inverted unfamiliar-race faces, while 7–8-month-old infants showed this effect only in upright unfamiliar-race faces. These results demonstrate that the face inversion effect of pupil contagion does not occur in 5–6-month-old infants, thereby suggesting the presence of the other-race effect in pupil contagion among this age group. Overall, this study provides the first evidence of the other-race effect on infants’ pupil contagion using face stimuli.

404 Mobile Pupillometry for Detection of Vasospasm, Delayed Cerebral Ischemia, and Neuro Exam Change in Subjects With Aneurysmal Subarachnoid Hemorrhage

INTRODUCTION: The pupillary light reflex (PLR) parameters are quantitative biomarkers that can be used to detect neurological disease. Vasospasm complicates aneurysmal subarachnoid hemorrhage (aSAH) trajectory, causing morbidity and mortality. METHODS: We prospectively collected PLR parameters from patients with aSAH admitted to a neurological intensive care unit twice daily using quantitative smartphone pupillometry recordings. PLR parameters included: Maximum pupil diameter (MAX), minimum pupil diameter (MIN), percent change in pupil diameter (CHANGE), latency in beginning of pupil constriction to light (LAT), mean constriction velocity (MCV), maximum constriction velocity (MAXCV), mean dilation velocity (MDV). One-tailed t-tests were performed to determine changes in PLR parameters between the following comparisons: (1) patients with and without radiographic vasospasm (defined by computed tomography angiography (CTA) or digital subtraction angiography (DSA)); (2) patients with and without delayed cerebral ischemia (DCI); and (3) patients with and without neurological exam change due to vasospasm. RESULTS: 42 total subjects were enrolled. For patients with (n = 13) and without (n = 29) radiographic vasospasm, significant PLR parameter differences were observed in: MAX (p = .024) and MIN (p = .0018). For patients with (n = 14) and without (n = 28) DCI, significant PLR parameter differences were observed in: CHANGE (p = .008). For patients with (n = 13) and without (n = 29) neurological exam change due to vasospasm, significant PLR parameter differences were observed in: MIN (34.7 vs 31.7, p = .014), CHANGE (20.6 vs 24.7, p = .025), and LAT (.36 vs .2, p = .0002). All other PLR parameters were not significantly different between groups for the three comparisons. CONCLUSIONS: Quantitative smartphone pupillometry may be of clinical use in the detection of radiographic vasospasm, DCI, and neuro exam changes via separate and distinct parameters from the PLR.

Evaluating the utility of quantitative pupillometry in a neuro-critical care setting for the monitoring of intracranial pressure: A prospective cohort study

IntroductionAssessment of the pupillary light reflex (PLR) is key in intensive care monitoring of neurosurgical patients, particularly for monitoring intracranial pressure (ICP). Quantitative pupillometry using a handheld pupillometer is a reliable method for PLR assessment. However, many variables are derived from such devices. We therefore aimed to assess the performance of these variables at monitoring ICP. MethodsSedated patients admitted to neurocritical care in a tertiary neurosurgical centre with invasive ICP monitoring were included. Hourly measurement of ICP, subjective pupillometry (SP) using a pen torch device, and quantitative pupillometry (QP) using a handheld pupillometer were performed. Results561 paired ICP, SP and QP pupillary observations from nine patients were obtained (1122 total pupillary observations). SP and QP had a moderate concordance for pupillary size (κ=0.62). SP performed poorly at detecting pupillary size changes (sensitivity=24%). In 40 (3.6%) observations, SP failed to detect a pupillary response whereas QP did. Moderate correlations with ICP were detected for maximum constriction velocity (MCV), dilation velocity (DV), and percentage change in pupillary diameter (%C). Discriminatory ability at an ICP threshold of >22 mmHg was moderate for MCV (AUC=0.631), DV (AUC=0.616), %C (AUC=0.602), and pupillary maximum size (AUC=0.625). ConclusionQP is superior to SP at monitoring pupillary reactivity and changes to pupillary size. Although effect sizes were moderate to weak across assessed variables, our data indicates MCV and %C as the most sensitive variables for monitoring ICP. Further study is required to validate these findings and to establish normal range cut-offs for clinical use.

Cognitive effort assessment through pupillary responses: Insights from multinomial processing tree modeling and neural interconnections

The pupillary responses of humans exhibit variations in size, which are mediated by optic and oculomotor cranial nerves. Due to their sensitivity and high resolution of pupillary responses, they are used for a long time as measurement metrics of cognitive effort. Investigating the extent of cognitive effort required during tasks of varying difficulty is crucial for understanding the neural interconnections underlying these pupillary responses. This study aims to assess human cognitive efforts involved in visually presented cognitive tasks using the multinomial processing tree (MPT) model, an analytical tool that disentangles and predicts distinct cognitive processes, resulting in changes in pupil diameter. To achieve this, a pupillary response dataset was collected during mental multiplication (MM) tasks and visual stimuli presentations as cognitive tasks. MPT model describes observed response frequencies across various response categories and determines the transition probabilities from one latent state to the next. The expectation maximization (EM) algorithm is employed with MPT model to estimate parameter values based on response frequency within each category. Both group-level and individual subject-to-subject comparisons are conducted to estimate cognitive effort. The results reveal that in the group comparison and with respect to task difficulty level, that subject’s knowledge on MM task influences the successfully solve the problem. Regarding individual analysis, no significant differences are observed in parameters related to correct recall, problem-solving ability, and time constraint compliance. However, some significant differences are found in parameters associated with the perceived difficulty level and ability to recall the correct answers. MPT model combined with EM algorithm constitutes a probabilistic model that enhances pupillary responses identification related to the cognitive effort. Potential applications of this model include disease diagnostics based on parameter values and identification of neural pathways that are involved in the pupillary response and subject’s cognitive effort. Furthermore, efforts are underway to connect this psychological model with an artificial neural network.

Evaluation of early period changes in intraocular pressure, ocular biometry and anterior segment after upper eyelid blepharoplasty.

To investigate the acute effects of upper eyelid blepharoplasty on intraocular pressure (IOP) and ocular biometric parameters. This prospective cross sectional study examined the eyes of 49 patients with dermatochalasis. Following a detailed ophthalmological examination, corneal topography was used to evaluate the eyes mesopic and photopic pupil diameter, anterior chamber depth, and corneal astigmatism on the day of surgery and on days first and seventh postoperatively. Ocular biometry was used to assess axial length and intraocular lens power. Goldmann applanation tonometry was used to measure intraocular pressure. Forty-nine eyes (26 males and 23 females) of 49 patients aged between 44 and 76years (mean 61 ± 7.9) were included in our study. The mean anterior chamber depth (ACD) was 2.90 ± 0.37mm preoperatively, 3.00 ± 0.29mm at postoperative day first, and 3.04 ± 0.29mm at postoperative day seventh, and the increase in anterior chamber depth was statistically significant (p < 0.001). The mean astigmatism values were measured as preoperative 0.73 ± 0.69 D, postoperative first day 0.93 ± 0.81 D, and postoperative seventh day 1.26 ± 0.90 D. The increase in astigmatism values was statistically significant (p < 0.001).The mean pupil diameter measurements in the mesopic environment were 4.20 ± 0.61mm preoperatively, 4.40 ± 0.59mm on the first postoperative day, and 4.39 ± 0.57mm on the seventh postoperative day, and there was a statistically significant difference between the three measurements (p = 0.03). The mean IOP measurements of the patients were 15.91 ± 3.51mmHg preoperatively, 16.81 ± 3.36mmHg on the first postoperative day, and 16.97 ± 3.13mmHg on the seventh postoperative day. The increase between these three measurements was statistically significant (p = 0.013). This study includes important insights into the potential acute phase impact of blepharoplasty surgery on ocular findings. Patients undergoing upper eyelid surgery should be informed about the possible change in ocular biometric parameters, intraocular pressure, and pupil diameter.

Quantitative analysis of dynamic iris changes in primary angle-closure disease with long axial lengths: the Handan Eye Study.

To investigate dynamic iris changes in patients with primary angle-closure disease (PACD) with long axial length (AL) compared to those with short and medium AL. This observational cross-sectional study enrolled participants aged 35 years or older from the Handan Eye Study follow-up examination who were diagnosed with PACD and underwent Visante anterior segment optical coherence tomography (ASOCT) imaging under light and dark conditions. The right eye of each participant was included in the analysis. AL was categorized as short (<22.0 mm), medium (≥22.0 to ≤23.5 mm), or long (>23.5 mm). Anterior segment parameters, including iris dynamic changes, were compared among the three groups with different ALs. Data from 448 patients with PACD were analyzed. We found that 10.9% of included eyes had a long AL with a flatter cornea; larger central anterior chamber depth, angle opening distance, anterior chamber width, anterior chamber area, and volume; and smaller lens thickness and lens vault (LV) (P < 0.05) than those with short AL. No significant difference existed between the three groups in iris thickness, iris cross-sectional area (IA), iris curvature, or pupil diameter (PD) change between light and dark (P > 0.05). The significant associated factors for IA changes were area recess area (ARA) in the dark, LV in the dark, and PD change from light to dark (P < 0.05). Dynamic and static iris parameters were consistent across patients with PACD with short, medium, or long AL and may contribute to the pathogenesis of angle closure in atypical PACD.

Long-Term Visual Quality and Pupil Changes after Small-Incision Lenticule Extraction for Eyes without Preoperative Cylinder Refraction.

To investigate the long-term changes in visual quality and pupil size after small incision lenticule extraction (SMILE) for eyes without preoperative cylinder refraction. Thirty-three myopic eyes (33 patients) without preoperative cylinder refraction were corrected using SMILE. Refractive outcomes, corneal curvature, aberrations, contrast sensitivity (CS), and pupil diameter were evaluated preoperatively, and 30 months postoperatively. The 30-month postoperative uncorrected and corrected distance visual acuity (UDVA and CDVA, LogMAR) were -0.10 ± 0.09 and -0.14 ± 0.06, respectively, whereas the preoperative CDVA (LogMAR) was -0.07 ± 0.05. Cylinder refraction of -0.11 ± 0.21 D (ranging from -0.50 to 0.00) was observed at 30 months postoperatively, increasing from the preoperative cylinder refraction of 0.00 ± 0.00 D (P=0.004). Moreover, the centroid coordinates x, y of corneal anterior astigmatic vectors were -0.19 ± 0.22, 0.81 ± 0.33 at 30 months postoperatively, and 0.02 ± 0.28, 0.76 ± 0.51 preoperatively (Px < 0.001 and Py=0.810, respectively). Furthermore, a 15° axis change in the mean anterior corneal astigmatic vector was observed at 30 months postoperatively from the preoperative state, as measured by Pentacam. At 30 months postoperatively, the photopic Log CS reduced significantly with glare at three and six cycles/degrees (P < 0.001 and P=0.015, respectively), a decreased photopic pupil diameter (3.27 ± 0.55 mm vs. 3.10 ± 0.66 mm, P=0.030), and an increased Coma (Z31) and Trefoil (Z3-3) at 4 mm diameter area analysis. However, a significant linear regression relationship was only observed between changes in photopic pupil diameter and changes in photopic Log CS with glare at 12 cycles/degree (P=0.038 and β = 0.282). Slight cylinder regression was observed with thicker corneal lenticular extraction after SMILE correction of nonastigmatic eyes 30 months postoperatively. This regression was mainly because of the axis changes in anterior corneal astigmatism power. Therefore, a cylinder nomogram modification of 0.25 to 0.50 D is considerable for correcting nonastigmatic myopic eyes with a predicted spherical lenticular thickness over 100 µm.

Cortical Zinc Signaling Is Necessary for Changes in Mouse Pupil Diameter That Are Evoked by Background Sounds with Different Contrasts.

Luminance-independent changes in pupil diameter (PD) during wakefulness influence and are influenced by neuromodulatory, neuronal, and behavioral responses. However, it is unclear whether changes in neuromodulatory activity in a specific brain area are necessary for the associated changes in PD or whether some different mechanisms cause parallel fluctuations in both PD and neuromodulation. To answer this question, we simultaneously recorded PD and cortical neuronal activity in male and female mice. Namely, we measured PD and neuronal activity during adaptation to sound contrast, which is a well-described adaptation conserved in many species and brain areas. In the primary auditory cortex (A1), increases in the variability of sound level (contrast) induce a decrease in the slope of the neuronal input-output relationship, neuronal gain, which depends on cortical neuromodulatory zinc signaling. We found a previously unknown modulation of PD by changes in background sensory context: high stimulus contrast sounds evoke larger increases in evoked PD compared with low-contrast sounds. To explore whether these changes in evoked PD are controlled by cortical neuromodulatory zinc signaling, we imaged single-cell neural activity in A1, manipulated zinc signaling in the cortex, and assessed PD in the same awake mouse. We found that cortical synaptic zinc signaling is necessary for increases in PD during high-contrast background sounds compared with low-contrast sounds. This finding advances our knowledge about how cortical neuromodulatory activity affects PD changes and thus advances our understanding of the brain states, circuits, and neuromodulatory mechanisms that can be inferred from pupil size fluctuations.

Pupillary Diameter Change and Dynamics in Different Refractive Error Groups after Implantation of a Collamer Lens with a Central Hole Without Viscoelastic Agent

Background: To investigate the pupillary diameter and dynamics in different refractive error groups after non-viscoelastic agent-assisted implantation of a collamer lens with a central hole, so as to evaluate the effect on the pupil of this type of surgery. Methods: Consecutive patients with a range of refractive errors who underwent non-viscoelastic agent-assisted implantation of a collamer lens with a central hole (ICL V4c) were analyzed. OPD-Scan III (NIDEK Japan)was used to measure the pupillary diameter preoperatively and 1 month postoperatively. Pupillary dynamics were assessed by calculating the scotopic pupillary diameter minus the photopic pupillary diameter. All variables were measured under photopic and scotopic conditions. Results: In 53 patients (medium-low myopia group 44 eyes, 23 patients, age 33.3±1.2 years and high myopia group 60 eyes, 30 patients, age 31.7±1.5 years), the postoperative photopic pupil was significantly smaller than preoperatively in both groups, and the postoperative pupillary size was significantly larger in the high myopia group under both the photopic and scotopic conditions. Besides, the high myopia group had a significantly larger photopic-scotopic change postoperatively and greater change in the pupillary dynamics. Conclusion: Implantation of a collamer lens with a central hole without viscoelastic agent assistance affected the pupillary diameter and dynamics at 1 month postoperatively in the medium-low and high myopia groups. The group with medium and low diopters had stronger changes in pupil diameter after surgery, while the group with high diopters was more likely to be affected by changes in visual quality.

A closer look at the time course of bodily responses to awe experiences

The structure and function of awe have been examined by focusing on the average level of outcomes during awe experiences. In the present study, we tested the psychophysiological process of experiencing awe, focusing on time-series changes in skin conductance responses (SCRs), a moment-by-moment measure of sympathetic nervous responses, and pupil diameter, which is dilated or constricted through the sympathetic and parasympathetic nervous system. The responses were measured through an experiment where 77 Japanese university students watched emotional (awe, amusement, or neutral) videos while moving a joystick when they felt supernatural agency or non-agency, examining the underlying psychological processes. We found that experiencing awe was associated with frequent and steep changes in SCRs and frequent changes in pupil diameter. The joystick inclination, the perceptions of the supernatural, was kept at a high level from the start to the end of awe experiences. These results may reflect the psychophysiological processes of awe: the “fluctuation” of the sympathetic nervous system might underlie awe-specific experiences. Our findings shed new light on the mechanisms of the body-mind interaction in awe experiences.

Linking vestibular, tactile, and somatosensory rhythm perception to language development in infancy

First experiences with rhythm occur in the womb, with different rhythmic sources being available to the human fetus. Among sensory modalities, vestibular, tactile, and somatosensory perception plays a crucial role in early processing. However, a limited number of studies so far have specifically focused on VTS rhythms in language development. The present work investigated VTS rhythmic abilities and their role in language acquisition through two experiments with 45 infants (21 females, sex assigned at birth; M age = 661.6 days, SD = 192.6) with middle/high socioeconomic status. Specifically, 37 infants from the original sample completed Experiment 1, assessing VTS rhythmic abilities through a vibrotactile tool for music perception. In Experiment 2, linguistic abilities were evaluated in 40 participants from the same cohort, specifically testing phonological and prosodic processing. Discrimination abilities for rhythmic and linguistic stimuli were inferred from changes in pupil diameter to contingent visual stimuli over time, through a Tobii X-60 eye-tracker. The predictive effect of VTS rhythmic abilities on linguistic processing and the developmental changes occurring across ages were explored in the 32 infants who completed both Experiments 1 and 2 by means of generalized, additive and linear, mixed-effect models. Results are discussed in terms of cross-sensory (i.e., haptic to hearing) and cross-domain (i.e., music to language) effects of rhythm on language acquisition, with implications for typical and atypical development.

Emotional response in babies’ pupil contagion

In this study, it was investigated whether an emotional response would occur in pupil contagion by using skin conductance response (SCR) in 5- and 6-month-old infants. In the experiment, emotional responses to pupil diameter change (dilating/constricting) between the face and eyes regions were compared by using pupil diameter response and SCR. The results showed that pupil diameter responses to pupil diameter changes did not differ between face and eyes regions. The emotional response indicated by the SCR significantly increased when participants looked at dilating pupils of face stimuli compared with when participants looked at constricted pupils of face stimuli. In addition, we found a significant correlation between SCR and pupil dilation in the face. This means that pupil diameter expansion significantly increases emotional response in pupil dilation of the face region.