Pupillary Function Research Articles

The Pupillary Light-Off Reflex in Acute Disorders of Consciousness.

In intensive care patients with disorders of consciousness, the pupillary light reflex is a measure of pupillary parasympathetic function. By contrast, the pupillary light-off reflex leads to pupil dilation in response to an abrupt change from light to darkness ("light-off") and reflects combined parasympathetic and sympathetic pupillary function. To our knowledge, this reflex has not been systematically investigated in patients with disorders of consciousness. We hypothesized that the pupillary light-off reflex correlates with consciousness levels after acute brain injury. From November 2022 to March 2023, we enrolled 100 study participants: 25 clinically unresponsive (coma or unresponsive wakefulness syndrome) and 25 clinically low-responsive (minimally conscious state or better) patients from the intensive care units of a tertiary referral center, and 50 age-matched and sex-matched healthy controls. Exclusion criteria were active or chronic eye disease. We used automated pupillometry to assess the pupillary light-off reflex and the pupillary light reflex of both eyes under scotopic conditions in all study participants. The pupillary light-off reflex was strongly correlated with consciousness levels (r = 0.62, p < 0.001), the increase in pupillary diameters being smallest in unresponsive patients (mean ± standard deviation 20% ± 21%), followed by low-responsive patients (mean ± standard deviation 47% ± 26%) and healthy controls (mean ± standard deviation 67% ± 17%; p < 0.001). Similar yet less pronounced patterns were observed for the pupillary light reflex. Twenty-one of 25 (84%) unresponsive patients had preserved pupillary light reflexes, but only seven (28%) had fully preserved pupillary light-off reflexes (p < 0.0001). Of these 7 patients, five (71%) regained awareness. The pupillary light-off reflex may be more sensitive to consciousness levels than the pupillary light reflex. The clinical implications of this finding seem worthy of further investigation, particularly regarding possible benefits for neuromonitoring and prognostication after brain injury.

Influencing Factors on Pupillary Light Responses as a Biomarker for Local Retinal Function in a Large Normative Cohort.

Investigating influencing factors on the pupillary light response (PLR) as a biomarker for local retinal function by providing epidemiological data of a large normative collective and to establish a normative database for the evaluation of chromatic pupil campimetry (CPC). Demographic and ophthalmologic characteristics were captured and PLR parameters of 150 healthy participants (94 women) aged 18 to 79 years (median = 46 years) were measured with L-cone- and rod-favoring CPC protocols. Linear-mixed effects models were performed to determine factors influencing the PLR and optical coherence tomography (OCT) data were correlated with the pupillary function volume. Relative maximal constriction amplitude (relMCA) and latency under L-cone- and rod-favoring stimulation were statistically significantly affected by the stimulus eccentricity (P < 0.0001, respectively). Iris color and gender did not affect relMCA or latency significantly; visual hemifield, season, and daytime showed only minor influence under few stimulus conditions. Age had a statistically significant effect on latency under rod-specific stimulation with a latency prolongation ≥60 years. Under photopic and scotopic conditions, baseline pupil diameter declined significantly with increasing age (P < 0.0001, respectively). Pupillary function volume and OCT data were not correlated relevantly. Stimulus eccentricity had the most relevant impact on relMCA and latency of the PLR during L-cone- and rod-favoring stimulation. Latency is prolonged ≥60 years under scotopic conditions. Considering the large study collective, a representative normative database for relMCA and latency as valid readout parameters for L-cone- and rod-favoring stimulation could be established. This further validates the usability of the PLR in CPC as a biomarker for local retinal function.

Outcome after Intracerebral Haemorrhage and Decompressive Craniectomy in Older Adults.

There is a relationship between the incidence of spontaneous intracerebral haemorrhage (ICH) and age. The incidence increases with age. This study aims to facilitate the decision-making process in the treatment of ICH. It therefore investigated the outcome after ICH and decompressive craniectomy (DC) in older adults (>65 years of age). Retrospective, multicentre, descriptive observational study including only consecutive patients who received DC as the consequence of ICH. Additive evacuation of ICH was performed after the individual decision of the neurosurgeon. Besides demographic data, clinical outcomes both at discharge and 12 months after surgery were evaluated according to the Glasgow Outcome Scale (GOS). Patients were divided into age groups of ≤65 and >65 years and cohorts with favourable outcome (GOS IV-V) and unfavourable outcome (GOS I to III). 56 patients were treated. Mean age was 53.3 (SD: 16.13) years. There were 41 (73.2%) patients aged ≤65 years and 15 (26.8%) patients aged >65 years. During hospital stay, 10 (24.4%) patients in the group of younger (≤65 years) and 5 (33.3%) in the group of older patients (>65 years) died. Mean time between ictus and surgery was 44.4 (SD: 70.79) hours for younger and 27.9 (SD: 41.71) hours for older patients. A disturbance of the pupillary function on admission occurred in 21 (51.2%) younger and 2 (13.3%) older patients (p = 0.014). Mean arterial pressure was 99.9 (SD: 17.00) mmHg for younger and 112.9 (21.80) mmHg in older patients. After 12 months, there was no significant difference in outcome between younger patients (≤65 years) and older patients (>65 years) after ICH and DC (p = 0.243). Nevertheless, in the group of younger patients (≤65 years), 9% had a very good and 15% had a good outcome. There was no good recovery in the group of older patients (>65 years). Patients >65 years of age treated with microsurgical haematoma evacuation and DC after ICH are likely to have a poor outcome. Furthermore, in the long term, only a few older adults have a good functional outcome with independence in daily life activities.

Intraocular pressure-related side-effects after endothelial keratoplasty.

To investigate circumpapillary retinal nerve fibre layer (RNFL) thickness, pupillary function and diameter after phacoemulsification and lens implantation alone or combined with endothelial keratoplasty (EK). This study was a secondary analysis of data from a randomized, single-masked trial, that included 72 patients with Fuchs' endothelial dystrophy and cataract, equally allocated (1:1) to ultrathin Descemet's stripping automated endothelial keratoplasty or Descemet's membrane endothelial keratoplasty. The cataract extraction (CE) group included 40 patients undergoing cataract surgery only. All patients were treated with phacoemulsification and lens implantation. RNFL thickness was significantly lower in the CE group than after EK for the global (p < 0.01), nasal (p = 0.04), and temporal sectors (p = 0.01) 12 months after surgery. RNFL thickness was comparable between patients treated with rebubbling and others (p ≥ 0.16 for all comparisons) after 12 months. The CE group and patients treated with EK demonstrated a comparable scotopic (p = 0.34) and photopic pupil diameter (p = 0.95) as well as a comparable maximum (p = 0.83) and average pupillary constriction velocity (p = 0.95) after 12 months. In contrast, patients treated with rebubbling had a significantly smaller scotopic pupil diameter (p = 0.04). In this study, no evidence was found indicating a negative impact on the RNFL thickness after EK when compared to CE 12 months after surgery. Iris function and pupil diameter were comparable between the CE group and patients treated with EK after 12 months.

The long-term effects of topical latanoprost 0.005% treatment on pupillary functions: A 2-year longitudinal study.

To investigate the long-term effects of topical latanoprost 0.005% treatment on pupillary functions in early-stage primary open-angle glaucoma (POAG) eyes using automated pupillometry. This prospective study involved 20 eyes of 20 treatment-naive subjects with early-stage POAG. After comprehensive ophthalmic examination, static and dynamic pupillometry measurements were performedbefore treatment, at the 1st follow-up visit (1.10 ± 0.30 months) and the 2nd follow-up visit (25.85 ± 10.26 months) after treatment initiation. Dynamic parameters included resting diameter (mm), amplitude (mm), latency (ms), duration (ms), and velocity (mm/s) of pupil contraction and dilation. Static pupillometry parameters were pupil diameter (PD, mm) in high-photopic, low-photopic, mesopic and scotopic conditions. The velocity of pupil dilation significantly decreased during the 1st visit (p = 0.008) and the 2nd visit (p = 0.0003) of treatment compared to the pre-treatment visit. The resting PD was also significantly higher after the 1st visit (p = 0.003) and the 2nd visit (p = 0.001) compared to the pre-treatment visit. However, the difference in resting PD measured between the 1st and 2nd visits did not reach statistical significance (p = 0.065). There were no significant changes in other dynamic parameters (p > 0.05 for all). Additionally, a mild, but not significant, mydriatic effect was observed in PD measurements under scotopic, mesopic and low photopic lighting conditions after follow-up. None of the static and dynamic parameters correlate with age, changes in intraocular pressure (IOP) or mean deviation (MD) values of visual field tests. The long-term topical latanoprost 0.005% treatment in early-stage POAG has a slight mydriatic effect on the pupil. Further longitudinal clinical studies with larger patient cohorts are necessary to better understand the effects of latanoprost on pupillary functions.

Neuro-Ophthalmic Adverse Events of COVID-19 Infection and Vaccines: A Nationwide Cohort Study.

To evaluate the association of COVID-19 infection and vaccination with neuro-ophthalmic adverse events. In this nationwide population-based retrospective cohort study, 8,498,353 patients were classified into three groups: control, COVID-19 infection, and COVID-19 vaccination. We conducted separate analyses for the early phase (within 60 days) and late phases (61-180 days) to estimate the incidence rates and hazard ratio (HR) for each neuro-ophthalmic adverse event. The adverse events included in this analysis were optic neuritis, papilledema, ischemic optic neuropathy, third nerve palsy, fourth nerve palsy, sixth nerve palsy, facial palsy, nystagmus, ptosis, blepharospasm, anomalies of pupillary function, and Guillain-Barré syndrome/Miller Fisher syndrome (GBS/MFS). Neuro-ophthalmic adverse events other than ptosis and GBS/MFS exhibited no significant increase after COVID-19, and their incidence was extremely low. The incidence rate of ptosis in both phases was significantly higher in patients administered COVID-19 vaccination (HR = 1.65 in the early phase and HR = 2.02 in the late phase) than in the control group. Additionally, BNT162b2 conferred a lower ptosis risk than ChAdOx1. GBS/MFS had a significantly higher incidence rate in the early phase (HR = 5.97) in patients with COVID-19 infection than in the control group. Ptosis was associated with COVID-19 vaccination, particularly with the ChAdOx1 vaccine, while GBS/MFS was associated with COVID-19 infection. In contrast, no association was found between other neuro-ophthalmic adverse events and COVID-19 infection or vaccination. These results may provide helpful insights for diagnosing and treating the neuro-ophthalmological adverse events after COVID-19.

Comparison of effects of volatile and intravenous anesthetics on pupillary function during general anesthesia in children: A prospective observational study.

The light reflex, which reflects central nervous system dysfunction, can also be affected by anesthetic agents. We evaluated whether these effects differed according to the anesthetic agent in pediatric patients. Twenty children aged 3-12 years who were scheduled to undergo elective surgery under general anesthesia were randomly allocated to propofol and sevoflurane groups and underwent pupillometric assessments at five points during anesthesia: T1, after confirming loss of consciousness; T2, after endotracheal intubation; T3, at the time of skin incision; T4, 1 h after skin incision; and T5, before endotracheal extubation. The primary outcome was the Neurological Pupil index at T4, and the secondary outcomes were other pupillometric parameters, including pupil diameter, percentage of change in pupil diameter, dilation velocity, and constriction velocity. At T4, the Neurological Pupil index was significantly lower in the sevoflurane group (median difference, 0.30; 95% CI, 0.00 to 0.70; p = .036). Furthermore, the Neurological Pupil index at all time points was lower in the sevoflurane group. The time-and-group interaction effects on constriction velocity and dilation velocity were significantly different [F(1, 4) = 16.68, p = .002; F(1, 4) = 14.78, p = .008, respectively] but were not different on the Neurological Pupil index, pupil diameter, and percentage of change in pupil diameter. No intergroup differences were observed in the baseline characteristics, the flow rate of remifentanil at each time point, and total infused remifentanil. The Neurological Pupil index value in pediatric patients under general anesthesia is affected by the anesthetic agent used; this factor requires consideration in evaluations of the Neurological Pupil index during general anesthesia.

Brimonidine eye drops reveal diminished sympathetic pupillary tone in comatose patients with brain injury

BackgroundThere is an urgent need for easy-to-perform bedside measures to detect residual consciousness in clinically unresponsive patients with acute brain injury. Interestingly, the sympathetic control of pupil size is thought to be lost in states of unconsciousness. We therefore hypothesized that administration of brimonidine (an alpha-2-adrenergic agonist) eye drops into one eye should produce a pharmacologic Horner’s syndrome if the clinically unresponsive patient is conscious, but not if the patient is unconscious. Here, in a first step to explore this hypothesis, we investigated the potential of brimonidine eye drops to distinguish preserved sympathetic pupillary function in awake volunteers from impairment of sympathetic tone in patients in a coma.MethodsWe enrolled comatose patients admitted for acute brain injury to one of the intensive care units (ICU) of a tertiary referral center, in whom EEG and/or neuroimaging for all practical purposes had ruled out residual consciousness. Exclusion criteria were deep sedation, medications with known drug interactions with brimonidine, and a history of eye disease. Age- and sex-matched healthy and awake volunteers served as controls. We measured pupils of both eyes, under scotopic conditions, at baseline and five times 5–120 min after administering brimonidine into the right eye, using automated pupillometry. Primary outcomes were miosis and anisocoria at the individual and group levels.ResultsWe included 15 comatose ICU patients (seven women, mean age 59 ± 13.8 years) and 15 controls (seven women, mean age 55 ± 16.3 years). At 30 min, miosis and anisocoria were seen in all 15 controls (mean difference between the brimonidine-treated pupil and the control pupil: − 1.31 mm, 95% CI [− 1.51; − 1.11], p < 0.001), but in none (p < 0.001) of the 15 ICU patients (mean difference: 0.09 mm, 95% CI [− 0.12;0.30], p > 0.99). This effect was unchanged after 120 min and remained robust in sensitivity analyses correcting for baseline pupil size, age, and room illuminance.ConclusionIn this proof-of-principle study, brimonidine eye drops produced anisocoria in awake volunteers but not in comatose patients with brain injury. This suggests that automated pupillometry after administration of brimonidine can distinguish between the extremes of the spectrum of consciousness (i.e., fully conscious vs. deeply comatose). A larger study testing the “intermediate zone” of disorders of consciousness in the ICU seems warranted.

Evaluation of Static and Dynamic Pupillary Functions in Early-Stage Primary Open Angle Glaucoma.

The dynamic parameters of the pupil, evaluated with an automated pupillometry device, differ in newly diagnosed early-stage primary open angle glaucoma (POAG) patients compared with healthy individuals, and this may guide us in early diagnosis and follow-up of glaucoma. To quantitatively determine static and dynamic pupillary functions in treatment-naive, newly diagnosed early-stage POAG patients and compare them with healthy controls. Forty eye of forty subjects with early POAG were compared with 71 eye of 71 age- matched and sex-matched healthy controls in terms of static and dynamic pupillary functions in this prospective and cross-sectional study. Static and dynamic pupillary functions were obtained with an automated pupillometry device. Static pupillometry parameters are pupil diameter (mm) in high photopic (100cd/m 2 ), low photopic (10cd/m 2 ), mesopic (1cd/m 2 ), and scotopic (0.1cd/m 2 ) light conditions. Dynamic pupillometry parameters are resting diameter (mm), amplitude (mm), latency (ms), duration (ms), and velocity (mm/s) of pupil contraction and dilation. Measured data were evaluated and compared with t test for independent groups. Duration of pupil contraction was lower, ( P =0.04) latency of pupil dilation time was longer, ( P =0.03) duration of pupil dilation was shorter ( P =0.04) and velocity of pupil dilation was lower ( P =0.02) in the POAG group. There was no significant difference between the 2 groups in terms of static pupillometry characteristics and the resting pupil diameter ( P >0.05 for all values). These results suggest that dynamic pupillary light responses may be affected in early-stage POAG compared with the normal population. Longitudinal studies with larger series are needed to better understand the quantitative changes in dynamic pupillometry functions in early-stage POAG.

This issue of ACTA

This issue of ACTA

Early Neurological Pupil Index Assessment to Predict Outcome in Cardiac Arrest Patients Undergoing Extracorporeal Membrane Oxygenation.

Early Neurological Pupil Index Assessment to Predict Outcome in Cardiac Arrest Patients Undergoing Extracorporeal Membrane Oxygenation.

Isolated Unilateral Ptosis Caused by Orbital Myositis Involving the Superior Rectus-Levator Muscle

Purpose: To present a case of orbital myositis involving the levator palpebrae superioris/superior rectus muscle (LPS/SR) complex with isolated unilateral ptosis and preserved extraocular muscle function and to review of the literature.Case summary: A healthy, 54-year old man presented with acute right upper ptosis detected 3 hours before. His best-corrected visual acuity was 20/20 in both eyes. His margin-reflex distance 1 was -2 mm and +4 mm, and levator function was 11 mm and 14 mm in the right and left eyes respectively. There was no proptosis. He had full extraocular motility with no strabismus, and normal pupillary function. There was no improvement in ptosis with the ice test and 0.5% apraclonidine test. Orbital magnetic resonance imaging demonstrated thickening and enhancement of right LPS/SR complex. Consequently, we diagnosed him with orbital myositis involving the LPS/SR complex. We started treatment with corticosteroid and ptosis completely resolved after 1 month since onset.Conclusions: We report a case of orbital myositis who showed inflammation of the LPS/SR complex early in the disease course and allowed the preservation of normal SR function. Inflammation of the LPS/SR complex might affect the function of these muscles differently due to the differences in muscle mechanics. Although orbital myositis involving LPS/SR complex is rare, it should be considered as a differential diagnosis in patients with acute unilateral ptosis.

Visit-to-Visit Blood Pressure Variability Are Associated with an Imbalance between Sympathetic and Parasympathetic Tone in Hypertensive Patients

Greater fluctuations in office blood pressure increase the risk of stroke and blood pressure volatility is an important risk factor for cardiovascular events. Effects of sympathetic and parasympathetic nerve on blood pressure regulation are well known, however, those on visit-to visit variation remains unclear. Aim of this study is to clarify the contribution of sympathetic and parasympathetic balance on blood pressure fluctuation. Methods: We enrolled 23 outpatients with essential hypertension. We measured blood pressure, and pulse rate at clinic 14 times in a row and calculated coefficient of variance (CV) as visit-to-visit variability. The velocity of pupil contraction, miosis (VC) and dilation, mydriasis (VD) was determined from pupillary function test. Results: Systolic blood pressure and diastolic blood pressure were not significantly correlated with VC, VD and VD/VC. Heart rate was not correlated with VC and VD, but significantly correlated with VD/VC. CV of systolic blood pressure, diastolic blood pressure and heart rate were not significantly correlated with VC or VD. Ratio of VD to VC significantly negative correlated with CV of blood pressure, diastolic blood pressure, and heart. Value of VD was significantly correlated with value of VC. Conclusion: Visit-to-visit variability of blood pressure and heart rate is not related with sympathetic or parasympathetic tone independently but augmented by the impaired sympathetic and parasympathetic balance.

Dynamic volume-rendered optical coherence tomography pupillometry.

To assess intrapupillary space (IPS) changes in healthy subjects with regard to decreased iris motility in patients with pseudoexfoliation glaucoma (PEXG) or non-arteritic anterior ischaemic optic neuropathy (NAION) in a feasibility study in a clinical environment. Scotopic and photopic IPS measurements using three-dimensionally rendered swept-source optical coherence tomography (SS-OCT) data were obtained and compared for all subjects. Intrapupillary space (IPS) parameters were evaluated such as absolute volumetric differences, relative light response for volumetric ratios and pupillary ejection fraction (PEF) for functional contraction measurements. From a total of 122 IPS from 66 subjects, 106 IPS were eligible for comparison providing values for 72 normal, 30 PEXG and 4 NAION eyes. In healthy, PEXG and NAION subjects, scotopic overall mean IPS was 8.90, 3.45 and 4.16 mm3 , and photopic overall mean IPS was 0.87, 0.74 and 1.13 mm3 , respectively. Three-dimensional contractility showed a mean absolute difference of 8.03 mm3 for normals (defined as 100% contractility), 2.72 mm3 for PEXG (33.88% of normal) and 3.03 mm3 for NAION (38.50% of normal) with a relative light response ratio between scotopic and photopic volumes of 10.26 (100%), 4.69 (45.70%) and 3.67 (35.78%), respectively. Pupillary ejection fraction (PEF) showed a contractile pupillary emptying of 88.11% for normals, 76.92% for PEXG and 70.91% for NAION patients. This 3D pupillometry OCT assessment allows for quantitative measurements of pupil function, contractility and response to light. More specifically, PEF is presented as a potential (neuro)-pupillary outcome measure that could be useful in the monitoring of ophthalmic disorders that affect pupillary function.

Quantification of Pupillary Dynamics and Accommodative Response in Adie’s Tonic Pupil: A Case Report

Background: Objective quantification of pupillary dynamics in a clinical setting is of worth importance to rule out any pupillary abnormalities. However, despite normal binocular vision findings, a quantitative measurement of pupillary response and accommodation provides a better insight to understand the mechanism. Case Report: This case report illustrates the clinical presentation, binocular vision parameters, Pupillary dynamics and accommodative response in a 33-year-old diagnosed with Adie’s Tonic pupil following trauma. Conclusion: This report explains the role of the pupillometer and open field autorefractor in quantitative analysis of pupillary and accommodative function.

Static and dynamic pupillary characteristics in multiple sclerosis.

To examine the static and dynamic pupillary functions with automated pupillography in multiple sclerosis (MS) patients with preserved visual acuity. 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. 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). 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.

Automated Pupillometry for Assessment of Treatment Success in Nonconvulsive Status Epilepticus.

Altered pupillary function may reflect nonconvulsive status epilepticus (NCSE). Neurological pupil index (NPi) assessed by automated pupillometry is a surrogate marker of global pupillary function. We aimed to assess NPi changes in relation to NCSE treatment response. In this prospective observational study, serial automated pupillometry was performed in 68 NCSE episodes. In accordance with local standards, patients were treated with clonazepam (1-2mg), levetiracetam (40mg/kg), and lacosamide (5mg/kg) in a stepwise approach under continuous electroencephalography monitoring until NCSE was terminated. Patients with refractory NCSE received individualized regimens. NPi was assessed bilaterally before and after each treatment step. For statistical analysis, the lower NPi of both sides (minNPi) was used. Nonparametric testing for matched samples and Cohen's d to estimate effect size were performed. Principal component analysis was applied to assess the contribution of baseline minNPi, age, sex, and NCSE duration to treatment outcome. In 97.1% of 68 episodes, NCSE could be terminated; in 16.2%, NCSE was refractory. In 85.3% of episodes, an abnormal baseline minNPi ≤ 4.0 was obtained. After NCSE termination, minNPi increased significantly (p < 0.001). Cohen's d showed a strong effect size of 1.24 (95% confidence interval 0.88-1.61). Baseline minNPi was higher in clonazepam nonresponders vs. responders (p = 0.008), minNPi increased in responders (p < 0.001) but not in nonresponders. NCSE refractivity was associated with normal baseline minNPi (principal component analysis, component 1, 32.6% of variance, r = 0.78), male sex, and longer NCSE duration (component 2, 27.1% of variance, r = 0.62 and r = 0.78, respectively). Automated pupillometry may be a helpful noninvasive neuromonitoring tool for the assessment of patients with NCSE and response to treatment.

Protective Effects of Fucoxanthin Dampen Pathogen-Associated Molecular Pattern (PAMP) Lipopolysaccharide-Induced Inflammatory Action and Elevated Intraocular Pressure by Activating Nrf2 Signaling and Generating Reactive Oxygen Species.

Inflammation and oxidative stress are closely related processes in the pathogenesis of various ocular diseases. Uveitis is a disorder of the uvea and ocular tissues that causes extreme pain, decreases visual acuity, and can eventually lead to blindness. The pharmacological functions of fucoxanthin, isolated from brown algae, induce a variety of therapeutic effects such as oxidative stress reduction and repression of inflammation reactions. However, the specific anti-inflammatory effects of fucoxanthin on pathogen-associated molecular pattern (PAMP) lipopolysaccharide-induced uveitis have yet to be extensively described. Therefore, the aim of present study was to investigate the anti-inflammatory effects of fucoxanthin on uveitis in rats. The results showed that fucoxanthin effectively enhanced the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) in ocular tissues. Furthermore, fucoxanthin significantly increased the ocular activities of superoxide dismutase and decreased the levels of malondialdehyde stimulated by PAMP-induced uveitis. Ocular hypertension and the levels of inflammatory cells and proinflammatory cytokine tumor necrosis factor-alpha in the aqueous humor were alleviated with fucoxanthin treatment. Consequently, compared to the observed effects in lipopolysaccharide groups, fucoxanthin treatment significantly preserved iris sphincter innervation and pupillary function. Additionally, PAMP-induced corneal endothelial disruption was significantly inhibited by fucoxanthin treatment. Overall, these findings suggest that fucoxanthin may protect against inflammation from PAMP-induced uveitis by promoting the Nrf2 pathway and inhibiting oxidative stress.

Pupillary light response after cataract surgery in healthy patients.

To examine the changes in the pupillary light response after phacoemulsification and to compare the difference in the response among patients in different age categories. Prospective observational study. Four-hundred twenty-two eyes of 422 patients in 3 age categories (60-69 years, 70-79 years, and 80-89 years) scheduled for phacoemulsification were consecutively enrolled. The eyes underwent examinations with an infrared pupillometer to obtain the parameters of the pupillary light response preoperatively and at 1 day and 1 and 3 months postoperatively. Differences in the parameters of the pupillary response were compared among 4 time intervals and the 3 age categories. The mean maximum and minimum pupillary diameters significantly decreased at 1 day postoperatively and returned to the preoperative level by 1 month postoperatively (P<.0001). The mean percentage of pupillary constriction was significantly reduced at 1 and 3 months postoperatively compared with preoperatively and at 1 day postoperatively (P<.0001). The average pupillary constriction and dilation velocities were significantly lower at 1 and 3 months postoperatively than they were preoperatively and at 1 day postoperatively (P<.0001). The latency to constriction did not differ significantly among the time intervals. The percentage of pupillary constriction was significantly smaller, and the average constriction and dilation velocities were lower in association with higher age categories at all time intervals (P≤.0185). The pupillary light response was impaired several months after cataract surgery and worsened with increasing patient age, indicating that cataract surgery may compromise the pupillary constriction and dilation functions in association with age.

Is Autonomic Nervous System Involved in the Epileptogenesis in Preterm Neonates?

Abstract Autonomic nervous system dysfunction has been described with focal and generalized epileptic seizures; occurring during their ictal, interictal, or postictal states. International League Against Epilepsy Seizure Classification Manual defines autonomic seizures as a distinct alteration of autonomic nervous system function involving cardiovascular, pupillary, gastrointestinal, sudomotor, vasomotor, and thermoregulatory functions. Autonomic seizures represent a great challenge for neonatologists and neurophysiologists; and distinguishing between ictal and non-ictal autonomic changes in neonates is rarely straightforward, especially in the premature ones. To avoid overdiagnosis and overtreatment, International League Against Epilepsy and the American Clinical Neurophysiology Society currently require electrographic correlation for any seizure diagnosis, including preterm neonates. There is very little scientific evidence about the pathophysiology of autonomic seizures. The data reporting on their incidence, clinical features, and diagnostic pathway is also insufficient. In this paper, we hypothesize that in the developing brain of preterm neonates, seizures involving deeper autonomic networks and subcortical structures might not propagate sufficiently to the cortex, and therefore the association of the seizures with specific ictal electrographic changes on surface electroencephalogram might be lacking. We propose considering autonomic seizures in the differential diagnosis of unexplained autonomic changes in neonates, especially preterm neonates, even in the absence of clear initial electrographic correlation. Unexplained autonomic changes could therefore be thought of as a “seizure alarm” in this population.