Difference In Pupil Diameter Research Articles

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.

Eighth Cervical Nerve Root Block During Interscalene Brachial Plexus Block Decreases Pain Caused by Posterior Portal Placement but Increases Horner Syndrome in Patients Undergoing Arthroscopic Shoulder Surgery: A Randomized Controlled Trial

To compare the intensity of pain on posterior portal placement between a C5-C7 root block (conventional interscalene brachial plexus block [ISBPB]) and a C5-C8 root block in patients undergoing arthroscopic shoulder surgery. In this prospective, single-blinded, parallel-group randomized controlled trial, patients were randomized to receive either a C5-C7 root block (C5-C7 group, n= 37) or a C5-C8 root block (C5-C8 group, n= 36) with 25 mL of 0.75% ropivacaine. The primary outcome was the pain intensity on posterior portal placement, which was graded as 0 (no pain), 1 (mild pain), or 2 (severe pain). The secondary outcomes were the bilateral pupil diameters measured 30 minutes after ISBPB placement; the incidence of Horner syndrome, defined as a difference in pupil diameter (ipsilateral - contralateral) of less than -0.5 mm; the onset of postoperative pain; and the postoperative numerical rating pain score, where 0 and 10 represent no pain and the worst pain imaginable, respectively. Fewer patients reported mild or severe pain on posterior portal placement in the C5-C8 group than in the C5-C7 group (9 of 36 [25.0%] vs 24 of 37 [64.9%], P= .003). Less pain on posterior portal placement was reported in the C5-C8 group than in the C5-C7 group (median [interquartile range], 0 [0-0.75] vs 1 [0-1]; median difference [95% confidence interval], 1 [0-1]; P=.001). The incidence of Horner syndrome was higher in the C5-C8 group than in the C5-C7 group (33 of 36 [91.7%] vs 22 of 37 [59.5%], P= .001). No significant differences in postoperative numerical rating pain scores and onset of postoperative pain were found between the 2 groups. A C5-C8 root block during an ISBPBreduces the pain intensity on posterior portal placement. However, it increases the incidence of Horner syndrome with no improvement in postoperative pain compared with the conventional ISBPB (C5-C7 root block). Level I, randomized controlled trial.

A Comparative Study of Vision Outcome Between Small Incision Cataract Surgery (SICS) and Phacoemulsification as Well as Comparison of Mydriatic Effects Between Two Drugs in Cataract Surgery Patients

Aims: Knowing the Mydriatic effect of Tropicamide and Cyclopentolate as well as the difference in vision improvement between phacoemulsification and small-incision cataract surgery. Study type and place: A prospective & cross-sectional study. Total number of cases 1446 were collected over a period of 6 month was conducted in Nagapattinam Government medical college. Objectives: To know the prevalence of cataracts on the basis of age and sex, To find the major systemic co-morbidities in cataract patients, To compare the pupil dilation between Tropicamide and Cyclopentolate, To compare the visual acuity after cataract surgery using SICS and phacoemulsification, To find drug utilization in pre- and post-operative cataract surgery Utilizing statistical analysis: The SPSS software package was used to compute and analyze the data. A 0.05 p value was deemed significant. Results: Among 1446 patients, gender distribution showed that 934 (65%) were female and 509 (35%) were male; According to age category, the majority of the patients in our study who have cataracts are between the ages of 60 and 79. The distribution of patients by eye wise was as follows: right eye (845, or 58%); left eye (601, or 42%); There were 624 cases of immature cataract (43%), 475 cases of mature cataract (32.8%), 289 cases of hyper-mature cataract (19.9%), and 58 cases of pseudophakia (4%).Patients undergoing cataract surgery frequently have diabetes and high blood pressure. One of the risk factors for cataract is diabetes (73.5%). SICS is more successful than phacoemulsification in terms of improving visual acuity, and since the pupil dilated larger with duration, it is Cyclopentolate rather than Tropicamide; Conclusions: By comparing visual acuity measured using the Snellen chart, there was a substantial difference in the visual outcome on the first postoperative day. Small-incision cataract surgery is more effective than phacoemulsification. The difference in pupil diameters between Cyclopentolate and Tropicamide demonstrates that the latter is less effective than the former. Keywords: Cyclopentolate, Diabetic mellitus, small incision cataract surgery, immature cataract, and female

Use of pupillometry for the evaluation of analgesia in dogs hospitalized in intensive care: A prospective study

A prospective study was performed on hospitalized conscious dogs. The objectives were: 1) to evaluate the feasibility and reliability of portable infrared pupillometry using a measure of photo light reflexes, 2) to identify parameters influencing measures, and 3) to compare parameters before and after the administration of analgesia.Twenty-nine dogs were included. Pupillometry was feasible by a single person. There was an excellent reliability for the evaluation of pupil diameter. There was poor to good reliability for the other parameters. There was an association between weight and mean pupil diameter (estimate = 0.1 mm, CI95 = [0.0; 0.1], P = 0.02), mean diameter variation (estimate = 0.2%, CI95 = [0.0; 0.4], P = 0.01), and mean velocity (estimate = 0.08 ms, CI95 = [0.03; 0.13], P = 0.002). Male dogs had a significantly larger mean pupil diameter than females (estimate = 1.3 mm, CI95 = [0.1; 2.5], P = 0.03). Independently of weight and sex, there was an association between mean pupil diameter and pain score: the higher the pain score, the lower the mean pupil diameter. There was a correlation between mean pupil diameter and morphine dose (ρ = −0.78, P = 0.0004). There was no significant difference in pupil diameter, velocity, and latency before and after analgesic administration.In conclusion, results do not support the use of PLR measurement by pupillometry as a pain assessment technique in hospitalized conscious dogs.

Does past/current pain change pain experience? Comparing self-reports and pupillary responses.

For decades, a substantial body of research has confirmed the subjective nature of pain. Subjectivity seems to be integrated into the concept of pain but is often confined to self-reported pain. Although it seems likely that past and current pain experiences would interact and influence subjective pain reports, the influence of these factors has not been investigated in the context of physiological pain. The current study focused on exploring the influence of past/current pain on self-reporting and pupillary responses to pain. Overall, 47 participants were divided into two groups, a 4°C-10°C group (experiencing major pain first) and a 10°C-4°C group (experiencing minor pain first), and performed cold pressor tasks (CPT) twice for 30 s each. During the two rounds of CPT, participants reported their pain intensity, and their pupillary responses were measured. Subsequently, they reappraised their pain ratings in the first CPT session. Self-reported pain showed a significant difference (4°C-10°C: p = 0.045; 10°C-4°C: p < 0.001) in the rating of cold pain stimuli in both groups, and this gap was higher in the 10°C-4°C group than in the 4°C-10°C group. In terms of pupillary response, the 4°C-10°C group exhibited a significant difference in pupil diameter, whereas this was marginally significant in the 10°C-4°C group (4°C-10°C: p < 0.001; 10°C-4°C: p = 0.062). There were no significant changes in self-reported pain after reappraisal in either group. The findings of the current study confirmed that subjective and physiological responses to pain can be altered by previous experiences of pain.

Automatic and controlled information processing in the context of students’ ethnic background and social status: An eye-tracking study

Based on the continuum model of impression formation (Fiske & Neuberg, 1990), information processing can be more or less automated or controlled and thus relies more or less on stereotype-based or individual-based characteristics. Also, teachers’ impression formation can be influenced by social categories like students’ ethnic background or social status. However, when teachers form an impression of students’ abilities or performance social categories should not play a role. But a lot of empirical findings show that teachers make a difference depending on students’ backgrounds. Whether this can be explained by a more automated or controlled information processing depending on students’ backgrounds is still an open question. Accordingly, the purpose of this study was to investigate teacher students’ impression formation in dependence on students’ ethnic backgrounds and social status. In order to investigate whether information processing differs according to students’ ethnic backgrounds and social status, an experimental eye-tracking study with 45 teacher students was designed. As physiological processes are strongly connected to psychological processes, specific eye-movements can be interpreted as indicators for physiological arousal in first place, but might also allow conclusions about mental processes like information processing. Pupil diameter and blink rate were measured while participants read three case vignettes with manipulated student background. Analysis of variance with repeated measures showed differences in pupil diameter and blink rate according to students’ background. Results showed less arousal when forming an impression about students without immigrant background and with high social status compared to students with immigrant background and with low social status. This might indicate more automated information processing for non-immigrant students with high-status, and more controlled processing for students with immigrant background and low-status.

Effect of anatomical differences and intraocular lens design on negative dysphotopsia.

To assess the effect of ocular anatomy and intraocular lens (IOL) design on negative dysphotopsia (ND). Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands. Ray-tracing study based on clinical data. Ray-tracing simulations were performed to assess the effect of anatomical differences and differences in IOL design on the peripheral retinal illumination. To that end, eye models that incorporate clinically measured anatomical differences between eyes of patients with ND and eyes of pseudophakic controls were created. The anatomical differences included pupil size, pupil centration, and iris tilt. The simulations were performed with different IOL designs, including a simple biconvex IOL design and a more complex clinical IOL design with a convex-concave anterior surface. Both IOL designs were analyzed using a clear edge and a frosted edge. As ND is generally considered to be caused by a discontinuity in peripheral retinal illumination, this illumination profile was determined for each eye model and the severity of the discontinuity was compared between eye models. The peripheral retinal illumination consistently showed a more severe discontinuity in illumination with ND-specific anatomy. This difference was the least pronounced, 8%, with the frosted edge clinical IOL and the most pronounced, 18%, with the clear edge biconvex IOL. These results show that small differences in the ocular anatomy or IOL design affect the peripheral retinal illumination. Therewith, they can increase the severity of ND by up to 18%.

The pupil and myself: pupil dilation during retrieval of self-defining memories.

There is a recent interest in pupil dilation during the retrieval of autobiographical memory. We pursued this line of research by measuring pupil diameter during the retrieval of self-defining memories, that is, memories that are highly vivid, emotionally intense, and are retrieved to reflect enduring concerns in a person's life. We invited 40 participants to retrieve self-defining memories while their pupil activity was recorder with eye-tracking glasses. We analyzed memories regarding specificity (i.e., specific or general) and emotional valence (neutral, positive, negative, or mixed). Analysis demonstrated larger pupil diameter during the retrieval of specific than general self-defining memories. However, no significant differences in pupil diameter were observed across the four emotional categories of self-defining memories. The increased pupil size during retrieval of specific self-defining memories can be attributed to the autonoetic experience during retrieval of these memories and/or to the cognitive load as required to construct these memoires. By investigating pupil dilation during the retrieval of self-defining memories, our study provides an original, ecological, and reliable physiological assessment of these memories.

Comparison of preoperative angle kappa measurements in the eyes of cataract patients obtained from Pentacam Scheimpflug system, optical low-coherence reflectometry, and ray-tracing aberrometry

BackgroundAngle kappa plays a vital role in the implantation of multifocal intraocular lens (MIOL). Large angle kappa is related to a higher risk of postoperative photic phenomena. This study aims to compare preoperative angle kappa in the eyes of cataract patients obtained from the Pentacam Scheimpflug system (Pentacam), optical low-coherence reflectometry (Lenstar), and ray-tracing aberrometry (iTrace).MethodsOne hundred thirteen eyes of 113 patients with cataracts were included. Each eye was examined 3 times using all devices to obtain angle kappa and pupil diameter. When considering dependent eyes for one individual, angle kappa in both right eyes and left eyes should be analysed separately. The repeatability and reproducibility were evaluated using the within-subject standard deviation (Sw), repeatability (2.77 Sw), and intraclass correlation coefficient (ICC). The difference, correlation, and agreement between devices were evaluated by paired t-tests, Pearson tests, and Bland-Altman analysis, respectively.ResultsIntraoperator repeatability and interoperator and intersession reproducibility of angle kappa showed an Sw of less than 0.05 mm, a 2.77 Sw of 0.14 mm or less, and an ICC of more than 0.96. Angle kappa was not significantly different between Pentacam and Lenstar (P > 0.05), while angle kappa was significantly different between Pentacam and iTrace and between Lenstar and iTrace (P < 0.05). There was a strong correlation between Pentacam and Lenstar for angle kappa (r =0.907 to 0.918) and a weak or moderate correlation between Pentacam and iTrace and between Lenstar and iTrace (r =0.292 to 0.618). There were narrow 95% limits of agreement (LoA) between Pentacam and Lenstar for angle kappa and wide 95% LoA between Pentacam and iTrace and between Lenstar and iTrace. No significant differences in pupil diameter were found between Pentacam and Lenstar in either eye (P > 0.05). Positive angle kappa (nasal light reflex) was found in most cataract patients (79.25% to 84.91%) through 3 different devices in both eyes.ConclusionsThe 3 devices provided high intraoperator repeatability and interoperator and intersession reproducibility for angle kappa measurements. The measurement of preoperative angle kappa in the eyes of patients with cataracts by Pentacam and Lenstar has good agreement.

Evaluation and Comparison of Posterior Corneal Elevation Parameters in Different Grades of Keratoconus by Pentacam

To evaluate and compare posterior corneal elevation data and anterior segment parameters in different grades of keratoconus by Pentacam. 114 eyes of 114 keratoconic patients (85 men and 56 women) with a mean age of 31.6±4.7 years were evaluated with a Pentacam Scheimpflug camera. Keratoconic eyes were divided into 3 groups or grades according to the maximum keratometry reading: mild or grade I (K=50 or less than 50 diopters [D]), moderate or grade II (K=50.0 to 55.0 D), and severe or grade III (K=55.0 D or higher). The posterior corneal parameters were obtained posterior. There were no statistically significant differences between keratoconus grades in terms of sex (P=0.661). Also, there were no statistically significant differences between 3 grades in terms of age (P=0.214). There were statistically significant differences in anterior keratometry readings (K), anterior chamber depth (ACD), anterior chamber angle (ACA), and all pachymetric corneal measurements between all groups. With the progression of the disease, posterior K readings and all posterior elevation measurements were statistically different between the three grades. However, there were no significant differences in pupil diameter, anterior chamber volume (ACV), and corneal volume (CV) between the three grades of keratoconus. According to the results of this study, height data of posterior elevation, when combined with corneal anterior segment parameter, could provide a useful keratoconus severity classification tool.

Dynamic assessment of variations in pupil diameter using swept-source anterior segment optical coherence tomography after phakic collamer lens implantation

PurposeTo dynamically assess variations in pupil diameter induced by changes in brightness in myopic eyes implanted with an implantable collamer lens (ICL, STAAR Surgical) with a central port.MethodsThis prospective, observational single-center case series study comprised 65 eyes from 65 consecutive patients undergoing ICL implant. A modified commercially available swept-source Fourier-domain anterior segment optical coherence tomography (AS-OCT) device was used for imaging and performing dynamic pupillometry under changing light conditions before and after a mean follow-up interval of four months after surgery.ResultsPreoperative mean pupil size under photopic conditions was 3.38 ± 0.64 mm; after surgery, this increased to 3.48 ± 0.61 mm. Mean pupil size under scotopic light conditions was 5.72 ± 0.79 mm before surgery and 5.84 ± 0.77 mm postoperatively. The differences between preoperative and postoperative pupil diameter in miosis and mydriasis were 0.10 ± 0.44 mm (P = 0.078) and 0.12 ± 0.58 mm (P = 0.098), respectively. The scotopic pupil exceeded the optic zone of the implanted lens in 39 eyes (60%). The mean central vault value was 412 ± 177 μm under maximum miosis and 506 ± 190 μm under maximum mydriasis. We found a positive correlation between vault and differences in pupil diameter under all light conditions (P < 0.05).ConclusionDynamic AS-OCT enables a very precise determination of the pupillary diameter in the iris plane. The changes in the pupil diameter under different light conditions after the implantation of an ICL are related to the postoperative vault.

Changes in Pupil Mydriasis as a Marker for Diabetes

Clinical Relevance: Optometrists often are the first to examine previously underdiagnosed diabetic patients because of its ocular manifestations such as a change in refractive status. This study is relevant to help optometrists identify patients with diabetes using changes in pupil mydriasis as a marker. Background: This study compared the pupillary dilatation in subjects with diabetes mellitus and those without diabetes mellitus. The purpose of the study was to use this difference as a diagnostic marker for identification of diabetes in previously undiagnosed subjects who present for eye examination. Methods: An experimental study was conducted involving 40 non-diabetic and 80 diabetic subjects with or without diabetic retinopathy. Baseline pupil diameter was measured using Orbscan and Aberrometer. Mydriasis was elicited using a combination eye drop (0.8% Tropicamide and 5% Phenylephrine). Pupil diameter was measured at 15, 30, 45 and 60 minutes after the instillation of the eye drops. The difference in pupil diameter amongst the three groups was determined using factorial ANOVA to account for the effect of age. Results: There was no significant difference between the mean pupil diameter among the three groups at baseline when measured with Orbscan (p=0.187) and Aberrometer (p=0.146). There was a significant difference in the mean and mean change in pupil diameter among the three groups with either Orbscan or Aberrometer at 30, 45 and 60 minutes after the instillation of mydriatic drops. The non-diabetics have larger pupil diameter while the diabetics with retinopathy have the least pupil diameter. Conclusion: The study showed that there was a significant difference in pupil diameter between non-diabetics, diabetics without retinopathy and diabetics with retinopathy during mydriasis. Alongside a history of symptoms of diabetes, this difference could be explored as an ocular biomarker to identify previously undiagnosed diabetes in individuals who present for routine eye examination.

Efficacy of Nepafenac versus Flurbiprofen in Maintaining Intraoperative Mydriasis During Phacoemulsification: A Comparative Study.

PurposeTo compare the efficacy of topical nepafenac (0.1%) with flurbiprofen (0.03%) in maintaining intra-operative mydriasis during phacoemulsification surgery.Patients and MethodsThis study comprised of 160 patients, who were divided into two arms of 80 each (arms A and B) after randomisation. Pre-operatively, all patients received one drop of tropicamide 0.8% and phenylephrine 5% (combination), 4 times, at an interval of 15 minutes on the day of surgery. Thereafter, Nepafenac drop in arm A/Flurbiprofen drop in arm B was administered 4 times, at an interval of 15 minutes keeping a gap of 10 minutes between tropicamide-phenylephrine and any of the experimental drugs. Phacoemulsification was performed one hour after the administration of last drop. Both vertical and horizontal pupillary diameter were measured at three steps; immediately before the surgical incision (baseline), at the end of emulsification of nucleus (before irrigation and aspiration) and at the end of surgery (after stromal hydration).ResultsThe difference in pupillary diameter between two groups, was statistically insignificant for vertical diameter (P = 0.08) and horizontal diameter (P = 0.28) at the start of surgery. On the other hand, pupillary diameter difference was statistically significant after emulsification of nucleus and at the end of surgery as well when both vertical (P < 0.05) and horizontal diameter (P < 0.05) were considered. The total reduction in pupillary diameter (both vertically and horizontally) was significantly less in the Nepafenac as compared to Flurbiprofen group (P < 0.05). Analysis of mean cumulative dissipated energy did not document any appreciable difference between the two groups. Phacoemulsification time analysis yielded statistically significant results (P = 0.004) between the Nepafenac and Flurbiprofen group.ConclusionIn the present study, topical Nepafenac (0.1%) proved to be more efficacious in maintaining intra-operative mydriasis during phacoemulsification surgery as compared to topical Flurbiprofen (0.03%).

Efficacy of a Cycloplegic Agent Administered as a Spray in the Pediatric Population.

To evaluate the efficacy and tolerability of cyclopentolate 1% administered as a spray in pediatric patients between 3 and 6 years old. In this prospective, randomized, parallel group study, healthy volunteers were randomly assigned to receive cyclopentolate 1% as a single drop or a single puff into closed eyes. There were 61 patients included in the study; 31 received cyclopentolate 1% as drops and 30 received cyclopentolate 1% as spray. The mean age at presentation was 4.5 ± 1.07 years (range: 3 to 6 years) and 4.2 ± 1.06 years (range: 3 to 6 years) in the drops and spray groups, respectively. The distress level was significantly lower at the time of receiving cyclopentolate as a spray (P < .0001), with the exception of patients aged 6 years. There were no significant differences in pupil diameter between the two groups (P = .51), whereas 5 of 30 patients (16.6%) with dark irises who received cyclopentolate spray did not have adequate cycloplegia to allow for accurate refraction. Cycloplegia achieved with cyclopentolate 1% administered as a spray may be an option in uncooperative children because it is less distressing compared to cyclopentolate 1% drops. However, physicians should be aware that cycloplegia obtained is only partially effective in children with dark irises. [J Pediatr Ophthalmol Strabismus. 2020;57(5):301-304.].

Difference in Pupillary Diameter as an Important Factor for Evaluating Amplitude of Accommodation: A Prospective Observational Study.

Presbyopia is increasing globally due to aging and the widespread use of visual display terminals. Presbyopia is a decrease in the eye’s amplitude of accommodation (AA) due to loss of crystalline lens elasticity. AA differs widely among individuals. We aimed to determine the factors that cause presbyopia, other than advanced age, for early medical intervention. We examined 95 eyes of 95 healthy volunteers (33 men, 62 women) aged 22–62 years (mean: 37.22 ± 9.77 years) with a corrected visual acuity of ≥1.0 and without other eye afflictions except ametropia. Subjective refraction, AA, maximum and minimum pupillary diameters during accommodation, axial length of the eye, and crystalline lens thickness were measured. AA was measured using an auto refractometer/keratometer/tonometer/pachymeter. The difference between maximum and minimum pupillary diameters was calculated. On multiple regression analysis, age and difference in pupillary diameter were both significantly and independently associated with AA in participants aged <44 years, but not in those aged ≥45 years. Our results suggest that the difference in pupillary diameter could be an important age-independent factor for evaluating AA in healthy individuals without cataract. Thus, improving the difference in pupillary diameter values could be an early treatment target for presbyopia.

Pupillary response in air force and air defence pilots when exposed to Gz+ acceleration

Background/Aim. In aviation, visual functions are important for the simultaneous monitoring the instrument panel and signs in the environment. From the very beginning of the development of aviation, visual function has been deemed particularly important. The effect of +Gz acceleration on the organ of vision is very significant for investigations in aviation medicine. Visual functions are the most important of all sensory functions where flight safety and quality of flight performance are concerned. High acceleration onset rates may cause changes in pupil diameter of a pilot with significant changes in visual function. However, it is important to maintain visual functions due to rapid pilot?s orientation in the space. The aim of this study was to establish whether there was any pupillary response in Air Force and Air Defence pilots or changes in pupil diameter when exposed to +Gz acceleration in the human centrifuge. ??thods. The study was conducted on 65 Air Force and Air Defence pilots aged from 28 to 45 years of age. The pilots were exposed to an acceleration of +5.5Gz to +7Gz. We examined the obtained differences in pupil diameter according to a rate of acceleration in the period of three consecutive days. R?sults. Changes in pupil diameter during the pilot?s exposure to different high values of acceleration in the course of three days, measured before, during and after the exposure, generated statistically significant results. No statistically significant differences in pupil diameter were noticed when the pilots were exposed to the same values of acceleration before the testing on the first, second or third day. During the test, pupil diameter was statistically significantly larger than before the test. Conclusion. Transient changes in pupil diameter occurred in pilots exposed to a +7Gz acceleration. Pilots were able to withstand exposure to a +5.5Gz acceleration, without any major changes in the pupil diameter. Physiological training of pilots in the human centrifuge mimicking conditions of real G acceleration, improves tolerance to acceleration, which is important for flight safety.

LEFT ‐RIGHT PUPIL DIAMETER DIFFERENCE‐DURING RADIOGRAPHIC READING OF BRONCOPULMONARY CARCINOMA: AN EXPLORATION WITH COGNITIVE LOAD AMONG NOVICES AND EXPERTS

INTRODUCTIONThe visual reading of an x‐ray image is a necessary process in order to find specific pathological patterns. With Functional Near Infrared Spectroscopy study have shown that increased levels of oxy and deoxy hemoglobin in the left hemisphere are associated with greater cognitive load in visual challenges and Transcranial Doppler has shown an increase on left middle cerebral artery flow associated with cognitive tasks in the face of visual challenges. Nowdays, pupil diameter begins to be recognized as a non‐intrusive method for measuring cognitive load during radiographic, dental radiographic, and histopathological diagnosis processes. The present work’s objective, is to show the difference in left and right pupillary diameters during the radiographic reading of bronchopulmonary carcinoma, to explore the cognitive burdens of novice, intermediate and expert groups.MATERIAL AND METHODSWith a 60 Hz Gazepoint GP3 Eyetracker, the pupil diameter of 8 doctors was quantified during the chest radiographic reading postero‐anterior projection of a bronchopulmonary carcinoma, taken from RadioGrapichs Magazine; first‐to‐fourth year resident physicians with age = 30.6 were classified as novice with 8.5‐month training, intermediate years with 41‐month training and expert doctors with age = 67 years and with 462 months of experience. All the diagnostic challenge was exposed on a monitor with 300 DPI connected to an Intel Core i5 PC with 8GB RAM.RESULTSThe average found of pupil diameter was 4.05 mm to all groups, over the course of 2 minutes, and the difference in pupil diameter went from 3.66 mm to 4.08 mm. However, the expert group demonstrated a pattern of smaller right pupil diameter with 3.98 mm, while the left pupillary diameter reached 4.22 mm. In contrast, during the same diagnostic task, the intermediate and novice groups showed a more homogeneous pupillary opening between left and right eye, being 4.05 mm and 4.01 mm respectively.Differences obtained between the left and right pupillary diameters during the chest x ray reading tasked were observed in all groups. However, it was observed that this difference occurred at different times. The expert group increased left pupillary diameter immediately while novice and intermediate achieved the same pupillary effect 50 seconds after the task was initiated. Fig 1.CONCLUSIONIn the two minutes radiological diagnosis process for bronchopulmonary carcinoma, radiologist doctors express greater left pupil diameter with respect to the right. However, experts make such a statement almost from the beginning of the task; while the intermediate and novice groups reach this same pattern approximately half way through the task’s total time. This finding, suggests that differences in pupil diameter may be associated with visual cognitive processing during diagnostic processes. This possible relationship may be related to cognitive load lateralization to the left hemisphere. Therefore, studies of cognitive load laterality vs. ipsilateral pupil diameter during imaging are necessary, since their possible effects on academic and labor scenarios are yet to be established.Support or Funding InformationPROSEIMLEFT ‐RIGHT PUPIL DIAMETER DIFFERENCE‐ DURING 2 MINUTES OF RADIOGRAPHIC READING OF BRONCHOPULMONARY CARCINOMA AMONG NOVICES AND EXPERTSFigure 1

Effects of prostaglandin-mediated and cholinergic-mediated miosis on morphology of the ciliary cleft region in dogs.

OBJECTIVE To compare morphology of the ciliary cleft (CC) region in dogs after topical administration of latanoprost, pilocarpine, or a combination of latanoprost and pilocarpine. ANIMALS 6 Beagles. PROCEDURES A prospective 4-phase crossover study with washout periods was performed. Latanoprost (phase L), pilocarpine (phase P), pilocarpine followed by latanoprost (phase PL), and latanoprost followed by pilocarpine (phase LP) were administered to the right eye. Artificial tears were administered to the left eye (control eye). For each phase, pupil diameter and intraocular pressure (IOP) were measured and ultrasonographic biomicroscopy was performed 2 hours after topical treatment. Angle opening distance (AOD), ciliary cleft width (CCW), ciliary cleft length (CCL), and ciliary cleft area (CCA) were evaluated. RESULTS All treated eyes had marked miosis without significant differences in pupil diameter among phases. Significant IOP reductions were detected for all phases, except phase P. The AOD and CCA were significantly increased in all phases for treated eyes, compared with results for control eyes. The CCW was significantly increased in phases P, PL, and LP; CCL was significantly increased in phases PL and LP. Comparison of treated eyes among phases revealed that CCW differed significantly between phases L and P and between phases L and PL. CONCLUSIONS AND CLINICAL RELEVANCE Prostaglandin-mediated and cholinergic-mediated miosis caused variations in CC configurations. When latanoprost and pilocarpine were used in combination, the first drug administered determined the cleft morphology, which was not fully reversed by the second drug. The CC morphology did not fully explain IOP reductions.

Physiologic anisocoria under various lighting conditions.

PurposeTo evaluate the measurement of anisocoria in a group of ocular healthy subjects using a standardized protocol in scotopic, mesopic, and photopic lighting conditions, and determine the optimal threshold of difference in pupil diameter in determining physiologic anisocoria.MethodsRight and left pupil diameters of 126 ocular healthy subjects with a mean age 30.5±7.8 years (40 males and 86 females) were measured sequentially under photopic conditions using a monocular infrared pupillometer. A sub-group of 51 individuals had right and left pupil measurements performed under three additional lighting conditions, allowing for a 2-minute recovery between measurements. A white light emitting diode (LED) in the eyecup of the pupillometer produced three controlled light settings: scotopic (0 lux), low mesopic (0.3 lux), and high mesopic (3 lux). The criterion for anisocoria was defined as ≥0.4 mm difference in pupil diameter between the eyes.ResultsIn the 126 subjects tested, 23.8% (n=30) exhibited anisocoria in photopic conditions. In the sub-group measured under three additional light settings, 43.1% (n=22) exhibited anisocoria in scotopic conditions, 43.1% (n=22) in low mesopic conditions, and 47.1% (n=24) in high mesopic conditions. Approximately 73% of subjects exhibited anisocoria in at least one light setting, while only approximately 8% had anisocoria in every light setting. When the criterion for anisocoria was shifted to ≥0.2 mm or ≥0.6 mm, the prevalence of anisocoria shifted significantly. Using a higher cutoff of ≥0.6 mm effectively reduced the number of healthy individuals who exhibit anisocoria in every light setting to almost zero.ConclusionBased on our data, anisocoria is more prevalent under varied lighting conditions. To ensure the anisocoria is due to physiologic reasons, one should ensure that it is present under all lighting conditions to avoid excessive false positives.

Pupillary response to nitrous oxide administration in cataract surgery under general anesthesia

BackgroundDespite recent innovations in cataract surgery, pupillary diameter is one of the most important affecting factors in outcome of this surgery. As cataract surgery is performed ideally when the pupil is sufficiently dilated, anesthesia may contribute significantly in success or failure of this operation. This study was performed to evaluate the effect of nitrous oxide on pupillary diameter in cataract surgery under general anesthesia. MethodsForty patients with cataract, scheduled for operation under general anesthesia, were randomly allocated into two groups. After induction of anesthesia, anesthesia was maintained with isoflurane and nitrous oxide – oxygen (60%-40%) in group 1 versus oxygen 100% in group 2. Pupillary diameter, heart rate and blood pressure were monitored and recorded, before induction of anesthesia, just before tracheal intubation, and one and 5 min after laryngoscopy and tracheal intubation. ResultsStatistical analysis of the results using Mann–Whitney test showed no significant difference in pupillary diameter between two the groups. ConclusionAccording to the results of this study, nitrous oxide has no effect on pupillary diameter of patients under general anesthesia, so it could be safety used, in this regard, in ophthalmic operations.