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Objectives: The aim of this prospective, longitudinal study was to validate video-oculography (VOG) for early detection of myasthenia gravis (MG) in patients with clinical suspicion of MG but lacking confirmatory laboratory results., Methods: Thirteen individuals suspected of having MG were studied using a 3-dimensional VOG system. Oculomotor fatigability, defined as the decrement (%) between the second and the last 5 average measures, was calculated., Results: Significant reductions in oculomotor ranges were found, exceeding previous cutoff values for horizontal saccades (16.4 ± 9.8%), vertical saccades (18.7 ± 12.6%), horizontal smooth pursuit (15.7 ± 6.0%), and vertical smooth pursuit (27.2 ± 17.4%). Despite initially negative laboratory tests, many participants later tested positive on the neostigmine test (92.3%) and repetitive nerve stimulation tests (69.2%)., Conclusions: VOG is a reliable diagnostic tool for MG, particularly useful for seronegative patients, allowing for earlier and more accurate diagnosis than conventional methods., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Cognitive dysfunction is regarded as one of the most severe aftereffects following coronavirus disease 2019 (COVID-19). Eye movements, controlled by several brain areas, such as the dorsolateral prefrontal cortex and frontal-thalamic circuits, provide a potential metric for assessing cortical networks and cognitive status. We aimed to examine the utility of eye movement measurements in identifying cognitive impairments in long COVID patients., Methods: We recruited 40 long COVID patients experiencing subjective cognitive complaints and 40 healthy controls and used a certified eye-tracking medical device to record saccades and antisaccades. Machine learning was applied to enhance the analysis of eye movement data., Results: Patients did not differ from the healthy controls regarding age, sex, and years of education. However, the patients' Montreal Cognitive Assessment total score was significantly lower than healthy controls. Most eye movement parameters were significantly worse in patients. These included the latencies, gain (computed as the ratio between stimulus amplitude and gaze amplitude), velocities, and accuracy (evaluated by the presence of hypermetric or hypometria dysmetria) of both visually and memory-guided saccades; the number of correct memory saccades; the latencies and duration of reflexive saccades; and the number of errors in the antisaccade test. Machine learning permitted distinguishing between long COVID patients experiencing subjective cognitive complaints and healthy controls., Conclusion: Our findings suggest impairments in frontal subcortical circuits among long COVID patients who report subjective cognitive complaints. Eye-tracking, combined with machine learning, offers a novel, efficient way to assess and monitor long COVID patients' cognitive dysfunctions, suggesting its utility in clinical settings for early detection and personalized treatment strategies. Further research is needed to determine the long-term implications of these findings and the reversibility of cognitive dysfunctions., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Oculomotor abnormalities are common in multiple sclerosis (MS) but are not quantitatively evaluated in clinical practice. Oculometric measures (OMs) are characteristics of eye movements captured while performing a visual task, e.g., the latency of saccadic and anti-saccadic metrics. Physical and cognitive deficits are prevalent among persons with MS, including disease-related oculomotor dysfunction. Recently, we have implemented a novel software-based platform enabling the extraction of OMs using a PC and a webcam., Objective: The objective of this study is to investigate the relationships between OMs and traditional outcome measures of physical and cognitive dysfunction in MS., Methods: Oculometric evaluation using a novel software-based platform (NeuraLight, Israel) was performed in patients with relapsing-remitting MS (n = 57; 36 females, age 41.4 ± 8.6). Physical disability was assessed by an MS-specific neurologic exam (Expanded Disability Status Scale; EDSS) and quantitative measures of cognitive and sensorimotor function (Symbol Digit Modalities Test; SDMT and Nine Hole Peg Test; NHPT). Various OMs were calculated out of multiple measures: Saccadic latency, gain and gaze during fixation, as well as error rate of saccades. Spearman's rank correlation was computed for each OM to assess the relationship with clinical scores., Results: Various OMs were correlated with EDSS scores, as pro- and anti-saccadic latency (OM1 r = 0.36, OM2 r = 0.50, OM3 r = 0.39, OM4 r = 0.49; P-values<0.0001), initial gain during saccades (OM6 r = 0.47, OM7 r = 0.30, OM8 r = 0.59; p < 0.0001), stability of gaze during fixation (OM9 r = 0.48, OM10 r = 0.41; p < 0.0001) and error rate of anti-saccades (OM11 r = 0.59; p < 0.0001). Similar correlations were found between these OMs and NHPT scores (OM1 r = 0.41, OM2 r = 0.46, OM3 r = 0.31, OM4 r = 0.50; P-values<0.0001), initial gain (OM6 r = 0.40, OM7 r = 0.39, OM8 r = 0.58; Ps<0.0001) and error rate (OM11 r = 0.36; p < 0.0001). Finally, OMs were correlated with SDMT scores: OM1 and OM2 r=-0.31, OM3 r=-0.26, SD r=-0.38; p < 0.05), OM7 r=-0.36, OM8 r=-0.45; Ps<0.0001) and fixation stability (OM9 r=-0.36, Om10 r=-0.45; p < 0.05)., Conclusions: OMs captured using a novel software-based platform were found to be associated with physical and cognitive function, suggesting that they can be used as a relevant tool in MS clinical assessment. Further studies will include larger cohorts and assess participants longitudinally to determine the potential value of OMs as predictors of future MS-related disability., Competing Interests: Declaration of competing interest Ilana Katz Sand and James F Sumowski declare no conflict of interests. Sarah Levy received salary support from the sponsor, NeuraLight. Rivka Kreitman is a consultant of NeuraLight, and Omer Berkman, Eitan Raveh and Edmund Ben-Ami are all employees of NeuraLight, which provided the software-based platform used for this study., (Copyright © 2025. Published by Elsevier B.V.)

Background: The psychometric properties of the Convergence Insufficiency Symptom Survey (CISS) have been previously determined across the younger adult population. This study investigated the psychometric properties of the CISS in presbyopic adults via classical and Rasch analysis., Methods: A total of 100 presbyopic individuals (40-60 years) were selected with far and near acuity of 20/20 with their habitual spectacles; 50 had convergence insufficiency and 50 had normal binocular vision. Refraction, cover test, near point of convergence, and positive fusional ranges were examined. The Persian translated CISS was administered twice, once in the first session and 7 to 14 days later. Classical and Rasch analyses were conducted., Results: The mean ages and gender ratios in the CI group and normal group were 49.70 ± 5.96 and 49.82 ± 5.64 years with a 50% female distribution among individuals. The mean CISS scores for presbyopes with CI and normal groups were 19.24 ± 5.33 and 13.26 ± 3.53 respectively (p < 0.001). Effective discrimination was achieved with a score greater than 15, yielding a sensitivity of 72%, a specificity of 69%, and an Area Under the Curve (AUC) of 0.813. For internal consistency, Cronbach's α coefficient was 0.82. For test-retest reliability in CISS scores, ICC was 0.91 (confidence interval 0.88-0.93) with the 95% limits of agreement in CI group being - 3.91 to 2.59. The Rasch analysis demonstrated a satisfactory model fit, as all items had infit and outfit mean square values ranging between 0.6 and 1.4. The measurement precision was good, with a person separation value of 2.30. Additionally, the first contrast eigenvalue of 2.34 and a raw variance of less than 50% indicated multidimensionality. The CI group reported headaches (item 3) more frequently than the normal binocular vision group did. However, eye discomfort scores (item 10) were similar for both groups., Conclusions: The CISS is a valid and reliable tool for assessing the symptoms in presbyopic adults. However, due to this survey's multidimensionality, we recommend additional objective examinations in presbyopic adults with CI., Competing Interests: Declarations. Ethics approval and consent to participate: This study is part of a larger research that received approval from the Research Ethics Committees of the Vice-Chancellor in Research Affairs at Shahid Beheshti University of Medical Sciences (Approval ID: IR.SBMU.RETECH.REC.1400.610) on November 28th, 2021, and has been registered on ClinicalTrials.gov under the identifier NCT05311917. The research project strictly adhered to the ethical guidelines outlined by the Declaration of Helsinki for conducting medical studies involving human subjects. Informed consent was obtained from all participants in the study by S.A. To safeguard the confidentiality of individuals, each participant was assigned a unique code, and access to the final data was restricted to S.A. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Purpose: Attention deficit and hyperactivity disorder (ADHD) is a neurodevelopmental condition commonly seen in children and adolescents, characterised by an increase in distractibility or inattention. Several studies have noted a higher rate of visual problems in this group, especially convergence insufficiency (CI), but when using different diagnostic criteria. The aim of this study was to evaluate visual function in ADHD children and non-ADHD controls to compare the different signs for diagnosis of CI., Method: In this prospective case-control study, a group of children aged 7-17 years, diagnosed with ADHD before the start of pharmacological treatment and matched for age and gender with non-ADHD controls were examined. Visual acuity (VA), objective and subjective refraction, accommodative amplitude and facility, heterophoria, positive and negative fusional vergences (PFV and NFV) and stereopsis were assessed., Results: Sixty participants (30 ADHD and 30 non-ADHD controls) were evaluated. There was no significant difference between the two groups for VA, refraction and accommodative abilities. There were significant differences in PFV and NFV: PFV break/recovery values for the ADHD and control groups were 18.9/16.2∆ and 26.9/22.1∆, respectively. Respective values for NFV were 15.7/13∆ and 19.3/15.9∆. Using the three signs of receded near point of convergence (NPC), decreased PFV and exophoria 4∆ greater at near than distance, the prevalence of CI was equivalent for the ADHD and controls (p = 0.34) If only two signs were considered for the CI diagnosis, (i.e., receded NPC and decreased PFV), then prevalence was significantly greater for the ADHD group (p < 0.01)., Conclusions: These results show a higher prevalence of binocular vision problems in the ADHD group. This suggests a relationship between vergence problems and ADHD, but the direction of this link remains unclear. Further studies with specific samples may be needed to understand fully the association between binocular vision disorders and ADHD., (© 2024 The Author(s). Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)

Background and Purpose: The dorsolateral portion of the caudal pons contains the vestibular nucleus (VN) and inferior cerebellar peduncle (ICP) that play important roles in conveying and processing vestibular and ocular motor signals. This study aimed to characterize ocular motor abnormalities along with their anatomical correlations in dorsolateral pons (DLP) lesions., Methods: We analyzed clinical features, and results of neuro-otological evaluations and neuroimaging of 18 patients with unilateral DLP lesions (17 with DLP infarction and 1 with cavernous malformation) from among 506 patients with pontine infarction in a stroke registry., Results: Most of the patients (n = 16) presented with isolated acute vestibular syndrome (AVS). The involved structures within the DLP were the ICP in four patients and the VN in the remaining 14. The unilateral ICP lesions were associated with consistent abnormalities in vestibular and ocular motor tests, including ipsilesional nystagmus without gaze-evoked nystagmus (GEN), and normal head impulse tests (HITs) and caloric response. In contrast, lesions of the VN were associated with a broader range of eye-movement abnormalities, including ipsi- or contralesional nystagmus with GEN, positive HITs, normal or abnormal caloric responses, and fixation nystagmus. Initial diffusion-weighted magnetic resonance imaging (within 48 h) was falsely negative in 41% (n = 7) of the DLP infarction cases., Conclusions: This study demonstrates that unilateral DLP lesions frequently present with isolated AVS and diverse ocular motor abnormalities. These characteristics may be due to the complex involvement of afferent or efferent fibers to and from the VN., (© 2024 The Author(s). European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

To investigate the characteristics and diagnostic values of the eye movement disorders in patients with Parkinson's disease (PD-EMDs), this cross-sectional study enrolled 127 Chinese patients with PD and 80 healthy controls, and divided them into training and validation sets based on enrollment time. Performance in the five oculomotor paradigms was assessed using an infrared pupil and a corneal reflection tracking device. The primary characteristics of PD-EMDs were elucidated as inaccurate fixation with high deviation (frequency and total quantity); inaccurate saccades with delayed reaction and low velocity; saccadic pursuit with high deviation, delayed reaction, and velocity; and decreased visual search ability. Subgroup comparison shows that PD-EMDs can be related with PD stages, motor subtypes, frozen gait, and drowsiness. Finally, we developed and externally validated a model for PD preliminary screening using multivariate stepwise logistic regression analysis, comprising four oculomotor parameters (fixation accuracy, pro-saccade velocity, anti-saccade accuracy, and visual search duration), cognition score and educational years. The model has good feasibility with satisfactory performance on the receiver operating characteristic, calibration, and decision curves, and broad clinical applicability with better discrimination for more advanced PD patients and non-tremor-dominant PD patients. A nomogram was created to make the model more user-friendly in the clinical setting. Overall, we have demonstrated the presence of PD-EMDs and their prospective value for PD preliminary screening., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 International Brain Research Organization (IBRO). Published by Elsevier Inc. All rights reserved.)

A 50-year-old male patient presented with a 10-year history of progressive cerebellar ataxia, multifocal dystonia with dystonic tremors, and oculomotor abnormalities including bilateral ptosis, slow saccades, and reduced range of ocular movements. There were no signs of cognitive impairment, parkinsonism, autonomic dysfunction, or muscle weakness, and the family history was unremarkable. This case presents the diagnostic approach to adult-onset cerebellar ataxia with dystonia and abnormal eye movements. In this era of genomic testing, our case highlights the role of clinical phenotyping and the utility of whole-exome sequencing in ataxias.

Background : Inferior oblique muscle overaction (IOOA) is a prevalent ocular muscle motility disorder. This study aimed to investigate the outcomes and impact of IO muscle myectomy with and without tucking the proximal end of the muscle into Tenon's capsule in two surgical groups as a treatment for IOOA. Methods : Randomized cohort study that involves two surgical groups. A total of 33 patients (55 eyes). Patients were randomly divided into two groups: first group underwent myectomy without tucking the proximal end of the muscle, whereas the second group underwent myectomy with tucking of the proximal end of the muscle. Each patient had four visits. During each visit, each patient had a comprehensive ophthalmic examination. Surgical success was defined as IOOA grade range of 0 to + 1 and correction of hypertropia in primary gaze. Results : The median age was 6 years. Sixteen (48.5%) patients underwent IO muscle myectomy with tucking, while 17 (51.5%) had an IO myectomy without tucking. Both the tucking and without tucking groups showed reductions in the angles of deviations, but there was no significant difference between the groups at baseline or postoperatively at 6 months. The success rate was 92.85% for the tucking group and 92.59% for the without tucking group. Conclusion : The study suggests that both surgical techniques are effective in correcting IOOA and associated HT, without any clear benefits of the addition of tucking. Ultimately, the two surgical techniques are equally effective, and the choice of surgical technique remains a personal preference of the surgeon.

Disease-specific oculomotor assessments play a crucial role in the early diagnosis of hereditary cerebellar ataxias. Whereas several studies have reported on quantitative oculomotor and vestibular measurements in Friedreich's Ataxia (FRDA), the value of specific oculomotor paradigms remains unclear. We aimed to address this knowledge gap through a systematic literature review and providing disease-specific recommendations for a tailored set of eye-movement recordings in FRDA. MEDLINE and Embase were searched for studies reporting on quantitative oculomotor and/or vestibular measurements in FRDA-patients. Data on oculomotor and vestibular parameters were extracted and correlations with a range of clinical parameters were sought. Included studies (n = 17) reported on 185 patients. Abnormalities observed included the presence of saccadic intrusions (143/161) such as square-wave jerks (SWJ, 90/109) and ocular flutter (21/43), impaired eccentric gaze-holding (40/104), abnormal pursuit (81/93) and angular vestibulo-ocular reflex (aVOR) deficits (39/48). For visually-guided saccades (VGS), we frequently observed increases in saccade latency (27/38) and dysmetric saccades (71/93), whereas saccade velocity was more often preserved (37/43). Augmented anti-saccade (AS) latency, downbeat nystagmus and frequent macro-SWJ correlated with disease duration. Increased AS-latency and VGS-latency, frequent macro-SWJ, reduced aVOR-gain and augmented aVOR peak-latency correlated with disease severity. A broad range of oculomotor and vestibular deficits are documented in the literature. Impairments in pursuit, saccades and aVOR-responses are most commonly reported, and as such, should be prioritized as disease markers. Quantitative oculomotor testing in FRDA may facilitate early diagnosis and prove valuable in monitoring disease progression and treatment response., Competing Interests: Declarations. Ethical Approval: Not applicable. Competing Interests: The authors declare no competing interests., (© 2024. The Author(s).)

Existing studies mainly focused on the inhibition of the task-interfering response to understand the inhibitory deficits of obsessive-compulsive disorder (OCD). However, recent studies suggested that inhibitory function is broadly involved in response preparation and implementation. It is yet unknown if the inhibition dysfunction in OCD extends beyond the task-interfering response to the general inhibitory function. Here we address this issue based on the multidimensional eye-movement measurements, which can better capture the inhibitory deficits than manual responses. Thirty-one OCD patients and 32 healthy controls (HCs) completed the anti-saccade task where multidimensional eye-movement features were developed. Confirmatory factor analysis (CFA) suggested two components of inhibitory function that negatively correlated with each other: one component of oculomotor hyperactivity in generating oculomotor output which is characterized with early premature saccades, early cross rates and saccade number; the other component of task-specific oculomotor efficiency which is characterized with task accuracy, saccade latency, correction rate, and amplitude gain. Importantly, OCD showed both stronger oculomotor hyperactivity and deficient oculomotor efficiency than HCs, and the machine-learning-based classifications showed that the features of oculomotor hyperactivity had higher prediction accuracy than the features of oculomotor efficiency in distinguishing OCD from HCs. Our results suggested that OCD has concurrent deficits in oculomotor hyperactivity and oculomotor efficiency, which may originate from a common inhibitory dysfunction., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: To describe CONCUSS, a randomized clinical trial (RCT) designed to compare the following: the effectiveness of immediate office-based vergence/accommodative therapy with movement (OBVAM) to delayed OBVAM as treatments for concussion-related convergence insufficiency (CONC-CI) to understand the impact of time (watchful waiting), the effect of OBVAM dosage (12 versus 16 therapy sessions), and to investigate the underlying neuro-mechanisms of OBVAM on CONC-CI participants., Methods: CONCUSS is an RCT indexed on https://clinicaltrials.gov/study/NCT05262361 enrolling 100 participants aged 11-25 years with medically diagnosed concussion, persistent post-concussive symptoms 4-24 weeks post-injury, and symptomatic convergence insufficiency. Participants will receive standard concussion care and will be randomized to either immediate OBVAM or delayed (by six weeks) OBVAM. At the Outcome 1 examination (week 7), clinical assessments of success as determined by changes in the near point of convergence (NPC), positive fusional vergence (PFV), and symptoms will be compared between the two treatment groups. After the Outcome 1 visit, those in the delayed group receive 16 visits of OBVAM, while those in the immediate OBVAM group receive four more therapy visits. Outcome 2 assessment will be used to compare both groups after participants receive 16 sessions of OBVAM. The primary measure is the between-group differences of the composite change in the NPC and PFV at the Outcome 1 visit. Secondary outcome measures include individual clinical measures, objective eye-tracking parameters, and functional brain imaging., Conclusions: Major features of the study design include formal definitions of conditions and outcomes, standardized diagnostic and treatment protocols, a delayed treatment arm, masked outcome examinations, and the incorporation of objective eye movement recording and brain imaging as outcome measures. CONCUSS will establish best practices in the clinical care of CONC-CI. The objective eye movement and brain imaging, correlated with the clinical signs and symptoms, will determine the neuro-mechanisms of OBVAM on CONC-CI., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Alvarez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The authors present the case of a 5-year-old boy who developed a unilateral internuclear ophthalmoplegia (INO) following mild head trauma with supporting magnetic resonance imaging (MRI) findings of damage to the medial longitudinal fasciculus. At 2 months of follow-up, the patient had resolution of diplopia and only minimal residual nystagmus. Although rare in the children, INO can develop following head trauma. Management should include work-up to exclude etiologies beyond trauma (specifically with MRI, which is superior to computed tomography imaging in evaluating INO) followed by observation and, if needed, comanagement of any amblyogenic potential from ocular misalignment. [ J Pediatr Ophthalmol Strabismus . 2024;61(6):e75-e77.] .

Purpose: To assess the long-term stability of clinical measures of convergence (near point of convergence [NPC] and positive fusional vergence [PFV]) in participants enrolled in the Convergence Insufficiency Treatment Trial-Attention and Reading Trial (CITT-ART) who received 16 weeks of office-based vergence/accommodative therapy., Methods: A total of 310 children, 9-14 years old, with symptomatic convergence insufficiency were enrolled in CITT-ART. Some 270 completed both their 16-week primary outcome visit followed by a 1-year follow-up visit. Of those 270, 181 (67%) were randomised to the vergence/accommodative therapy. Of the 181 in the vergence/accommodative group, 121 (67%) reported not receiving any additional treatment after the 16-week primary outcome visit. The mean change in NPC, PFV and percentages of children classified by the predetermined success criteria of convergence (normal NPC [<6 cm] and/or improved by ≥4 cm; normal PFV [passing Sheard's criterion and base-out break >15Δ] and/or improved by ≥10Δ) were compared at the 16-week primary outcome visit and 1 year later., Results: Of the 121 who returned for their 1-year follow-up visit, there was no significant change in mean adjusted NPC (reduction of -0.2 cm; 95% CI: -1.0 to 0.5 cm) at 1 year. There was a statistically significant decrease in mean-adjusted PFV (-4.7∆; 95% CI: -6.5 to -2.8Δ) at 1 year. There were similar percentages of participants classified as 'normal' (p = 0.30), 'normal and/or improved' (p > 0.50) and 'normal and improved' (p > 0.14) based on NPC and PFV at the 1-year visit compared with the 16-week primary outcome visit., Conclusion: The improvements in NPC and PFV following 16 weeks of vergence/accommodative therapy (with no reported additional treatment thereafter) in children with symptomatic convergence insufficiency persisted 1-year post-treatment., (© 2024 The Author(s). Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)

Objective : Saccadic Intrusions (SIs) are abnormal eye movements during gaze fixation. Studies have indicated the clinical relevance of SIs, especially of square wave jerks (SWJ) in ALS. We used a software-based platform to extract SIs as a part of an interventional drug trial. The objective was to examine SIs' change over time as a potential biomarker of ALS disease progression. Methods : 28 ALS patients (61.95 ± 8.6 years) were assessed with the revised ALS Functional Rating Scale (ALSFRS-R) and with an oculometric test. Changes of SIs over time and correlations with ALSFRS-R and its bulbar subscale were calculated. A power calculation was conducted to understand the practical implications of results. Results : A significant increase of SWJ over trial duration was observed, with an increase in frequency (mean rise of 0.14 ± 0.28, p < 0.01), amplitude (0.001 ± 0.0016 degrees, p < 0.005), overall duration of SWJ (0.13 ± 0.25, in %, p < 0.01), and in their relative part out of all intrusions (0.18 ± 0.32, in %, p < 0.005). Negative correlations were found with the bulbar subscale (R=-0.43, -0.41, -0.39 and -0.47, respectively, p < 0.001). The required sample size for observing a 40% reduction in bulbar aspects when using the oculometric test (α = 0.05 and β = 0.8), was found to be 150 patients per arm, compared with 200 patients using the bulbar subscale. Conclusions : Evaluation of saccadic intrusions during fixation was able to detect disease progression over time, correlated with ALSFRS-R bulbar subscale. Eye movements can potentially serve as an objective biomarker in ALS clinical trials and reduce the required sample size to show clinical effect of therapies.

Background: Thrombosis of the superior ophthalmic vein (SOV) is rare. It can present with heterogeneous symptoms and requires a careful diagnostic work-up., Methods: This article reports on a case series of three female patients with thrombosis of the SOV and performed an extensive review of the existing literature in PubMed., Results: All three patients showed different leading symptoms but all had a triad of restricted eye motility, exophthalmos and a difference in intraocular pressure with the higher pressure on the side of the protruded eyeball. The pathophysiological background differed in all cases: in the two first cases a pre-existing anticoagulation treatment had been paused shortly before the event. Cofactors were an intraorbital venous outflow obstruction due to an unclear mass in the orbital apex in one case and hypercoagulability due to a malignant disease in the other case. In the third case, there was a cavernous sinus fistula., Conclusion: The diagnosis should be considered not only in patients with dilated vessels of the anterior segment but also in unclear cases of exophthalmos or unilateral elevated intraocular pressure (IOP)., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Objectives: Mutations in the X-linked endosomal Na+/H+ exchanger 6 (NHE6) cause Christianson syndrome (CS). Here, in the largest study to date, we examine genetic diversity and clinical progression in CS into adulthood., Method: Data were collected as part of the International Christianson Syndrome and NHE6 ( SLC9A6 ) Gene Network Study. 44 individuals with 31 unique NHE6 mutations, age 2-32 years, were followed prospectively, herein reporting baseline, 1 year follow-up and retrospective natural history., Results: We present data on the CS phenotype with regard to physical growth and adaptive and motor regression across the lifespan including information on mortality. Longitudinal data on body weight and height were examined using a linear mixed model. The rate of growth across development was slow and resulted in prominently decreased age-normed height and weight by adulthood. Adaptive functioning was longitudinally examined; a majority of adult participants (18+ years) lost gross and fine motor skills over a 1 year follow-up. Previously defined core diagnostic criteria for CS (present in>85%)-namely non-verbal status, intellectual disability, epilepsy, postnatal microcephaly, ataxia, hyperkinesia-were universally present in age 6-16; however, an additional core feature of high pain tolerance was added (present in 91%). While neurologic examinations were consistent with cerebellar dysfunction, importantly, a majority of individuals (>50% older than 10) also had corticospinal tract abnormalities. Three participants died during the period of the study., Conclusions: In this large and longitudinal study of CS, we begin to define the trajectory of symptoms and the adult phenotype thereby identifying critical targets for treatment., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

The oculomotor abnormalities have been reported in some dyslexic children. The purpose of the study was to evaluate the effects of oculomotor rehabilitation on the reading performance of dyslexic children. Subjects were 50 dyslexic children. Those with oculomotor abnormalities ( n = 30) were randomly assigned into 2 groups matched for age. The case group received oculomotor rehabilitation. The rehabilitation program consists of 3 different exercises. The reading and dyslexia tests were performed before and after the intervention. The correct scores of reading tests in the case group posttest increased significantly compared with the control group, and there is a significant difference between the two groups ( P = .001). The positive effects of oculomotor rehabilitation on the reading performance of dyslexic children confirmed that the oculomotor program could be a practical tool for improving reading performance in dyslexic children., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Parinaud syndrome, also known as dorsal midbrain syndrome, is a condition affecting the dorsal midbrain region of the brainstem that presents with a triad of ophthalmic clinical findings, including upgaze paresis, convergence retraction nystagmus, and light-near dissociation. This case report will discuss the clinical presentation of Parinaud syndrome in a four-year-old patient who was seen in an out-patient clinic for intermittent exotropia 5 months after a suboccipital craniotomy resection of a pineal mass and ventriculoperitoneal (VP) shunt placement for associated hydrocephalus. Current literature is relatively sparse regarding the presentation of Parinaud syndrome in the pediatric population, with little known about prognosis and potential for recovery. The purpose of this case report is to identify the neuro-ophthalmic clinical findings associated with a pineal mass, examine how these findings may present in a pediatric patient, and discuss in detail the neuroanatomy and pathophysiology of the major clinical findings associated with Parinaud syndrome.

Oculomotor synkinesis is an unusual phenomenon that encompasses various presentations with few associations reported in the literature. It can occur with or without a previous setting of oculomotor nerve injury. The authors present the first reported case of bilateral congenital trochlear-oculomotor synkinesis in a 5-month-old infant. [ J Pediatr Ophthalmol Strabismus . 2024;61(5):e50-e53.] .

Kleine-Levin syndrome (KLS) is a rare, recurring sleep disorder that easily ignored. Episodic upward-gaze palsy is an uncommon manifestation observed in patients of KLS, which further complicates this disorder. Although peripheral microbial infection have been recognized as most common triggers for KLS, the underlying pathophysiology of this disorder remains unclear. We reported a unique case of KLS elicited by acute encephalitis, which was confirmed by pleocytosis of cerebrospinal fluid at the early stage. The cerebrospinal fluid returned to normal over time while the attacks continued to recur frequently. Episodic upward-gaze palsy was observed during attacks and clinical symptoms were exacerbated following a subsequent COVID-19 infection. This report presents a classic KLS case with distinctive characteristics, which should facilitate more accurate and earlier diagnosis for clinicians. Furthermore, it provides a new perspective for understanding the pathogenesis of this rare disease., Citation: Lv H, Long X, Lv Y, Zhou J. Acute encephalitis induced Kleine-Levin syndrome with episodic vertical gaze dysfunction during hypersomnia episodes. J Clin Sleep Med . 2024;20(9):1555-1556., (© 2024 American Academy of Sleep Medicine.)

Competing Interests: The author reports no conflicts of interest.

Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Competing Interests: The authors report no conflicts of interest.

Competing Interests: The authors report no conflicts of interest.

Introduction: Convergence Insufficiency (CI) is the most prevalent oculomotor dysfunction of binocular vision that negatively impacts quality of life when performing visual near tasks. Decreased resting-state functional connectivity (RSFC) is reported in the CI participants compared to binocularly normal control participants. Studies report that therapeutic interventions such as office-based vergence and accommodative therapy (OBVAT) can improve CI participants' clinical signs, visual symptoms, and task-related functional activity. However, longitudinal studies investigating the RSFC changes after such treatments in participants with CI have not been conducted. This study aimed to investigate the neural basis of OBVAT using RSFC in CI participants compared to the placebo treatment to understand how OBVAT improves visual function and symptoms., Methods: A total of 51 CI participants between 18 and 35 years of age were included in the study and randomly allocated to receive either 12 one-hour sessions of OBVAT or placebo treatment for 6 to 8 weeks (1 to 2 sessions per week). Resting-state functional magnetic resonance imaging and clinical assessments were evaluated at baseline and outcome for each treatment group. Region of interest (ROI) analysis was conducted in nine ROIs of the oculomotor vergence network, including the following: cerebellar vermis (CV), frontal eye fields (FEF), supplementary eye fields (SEF), parietal eye fields (PEF), and primary visual cortices (V1). Paired t-tests assessed RSFC changes in each group. A linear regression analysis was conducted for significant ROI pairs in the group-level analysis for correlations with clinical measures., Results: Paired t-test results showed increased RSFC in 10 ROI pairs after the OBVAT but not placebo treatment (p < 0.05, false discovery rate corrected). These ROI pairs included the following: Left (L)-SEF-Right (R)-V1, L-SEF-CV, R-SEF-R-PEF, R-SEF-L-V1, R-SEF-R-V1, R-SEF-CV, R-PEF-CV, L-V1-CV, R-V1-CV, and L-V1-R-V1. Significant correlations were observed between the RSFC strength of the R-SEF-R-PEF ROI pair and the following clinical visual function parameters: positive fusional vergence and near point of convergence (p < 0.05)., Conclusion: OBVAT, but not placebo treatment, increased the RSFC in the ROIs of the oculomotor vergence network, which was correlated with the improvements in the clinical measures of the CI participants., (© 2024 The Author(s). CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)

Background and Objectives: The diagnostic challenge of myasthenia gravis (MG) is exacerbated by the variable efficacy of current testing methodologies, necessitating innovative approaches to accurately identify the condition. This study aimed to assess ocular muscle fatigue in patients with MG using video-oculography (VOG) by examining repetitive saccadic eye movements and comparing these metrics to those of healthy control participants., Methods: This prospective, cross-sectional study was conducted at a tertiary care center and involved 62 patients diagnosed with MG (48 with ocular MG and 14 with generalized MG) and a control group of 31 healthy individuals, matched for age and sex. The assessment involved recording saccadic eye movements within a ± 15° range, both horizontally and vertically, at a rate of 15 saccades per minute over a 5-min period, resulting in 75 cycles. Participants were afforded a 3-min rest interval between each set to mitigate cumulative fatigue. The primary outcome was the detection of oculomotor fatigue, assessed through changes in saccadic waveforms, range, peak velocity, latency, and the duration from onset to target, with a focus on comparing the second saccade against the average of the last five saccades., Results: In the evaluation of repetitive saccadic movements, patients with MG exhibited a reduced saccadic range and a prolonged duration to reach the target, compared to healthy subjects. Furthermore, a significant elevation in the frequency of multistep saccades was observed among MG patients, with a marked rise observed over consecutive trials. Receiver operating characteristic (ROC) analysis revealed the discriminative performance of multistep saccade frequency, in conjunction with variations in saccadic range and duration from onset to target achievement between the second saccade and the mean of the final five saccades, as effective in distinguishing MG patients from healthy subjects. Although alterations in peak saccadic velocity and latency were less pronounced, they were nevertheless detectable., Discussion: The utilization of VOG for repetitive saccadic testing in the diagnosis of MG has demonstrated considerable diagnostic precision. This methodology affords significant accuracy in evaluating ocular muscle fatigue in MG patients, providing class III evidence supportive of its clinical application., (© 2024. Springer-Verlag GmbH Germany, part of Springer Nature.)

Saccadic oscillations (SOs) mostly occur spontaneously, but can be occasionally triggered by various stimuli. To determine clinical characteristics and underlying mechanisms of triggered SOs, we analyzed the clinical features and quantitative eye-movement recordings of six new patients and 10 patients in the literature who exhibited with triggered SOs. Eleven of the 16 patients (69%) had a lesion involving cerebellum and/or brainstem such as cerebellar degeneration, cerebellitis, or cerebellar infarction. The other causes were vestibular migraine (n = 2), multiple sclerosis (n = 1), Krabbe disease (n = 1), and idiopathic (n = 1). Vestibular stimulation was the most common trigger (n = 11, 69%), followed by removal of visual fixation (n = 4, 25%), hyperventilation (n = 1), light (n = 1), and blink (n = 1). The types of triggered SOs were varied which included ocular flutter (n = 13), opsoclonus (n = 3), vertical SOs (n = 2), and macrosaccadic oscillations (n = 1). Three patients exhibited downbeat nystagmus either before (n = 1) or after (n = 2) the onset of SOs. The frequency of triggered SOs ranged from 4 to 15 Hz, and oscillations with smaller amplitudes had higher frequencies and smaller peak velocities. SOs can be triggered by the modulation of unstable saccadic neural networks through vestibular and visual inputs in lesions of the brainstem and cerebellum., (© 2024. Springer-Verlag GmbH Germany, part of Springer Nature.)

A clinical scale fully dedicated to evaluating ocular motor abnormalities is required for now. We investigated the utility of a recently developed Scale for Ocular motor Disorders in Ataxia (SODA) in patients with multiple system atrophy (MSA). We prospectively assessed SODA in consecutive patients with MSA between August 2021 and August 2023 at the Korea University Medical Center. The results of the clinical exam-based SODA were compared with those measured using video-oculography (VOG-guided SODA). We also compared the findings with other established clinical scales targeting patients with MSA, including the Unified Multiple System Atrophy Rating Scale (UMSARS) I-II, Movement Disorder Society-Unified Parkinson's Disease Rating Scale motor part (UPDRS-III), Scale for Assessment of Rating of Ataxia (SARA), Composite Autonomic Symptom Score-31 (COMPASS-31), and Composite Autonomic Severity Score (CASS). Twenty patients were enrolled in our study (17 with cerebellar-type MSA and three with Parkinson-type MSA). Scores ranged from 1 to 14 (median [interquartile range (IQR)] = 8 [5-10]). Among the subscales, saccades had a median score of 2.5 (IQR = 1-3), followed by ocular pursuit (1 [0-1]), nystagmus (1 [0-2]), saccadic intrusions (1 [0-1]), vestibulo-ocular reflex (VOR) (0.5 [0-1]), ocular alignment (0 [0-1]), and VOR cancellation (1 [0-1]). The clinical-exam-based SODA (p = 0.020) and VOG-guided SODA (p = 0.034) positively correlated with disease duration. No correlation was found between clinical exam-based SODA and other scales. Skew deviation, gaze-evoked nystagmus, VOR cancellation, and smooth pursuit had the highest precision among the items. Ocular misalignment and spontaneous and positional nystagmus were frequently false positive and were poorly detected with clinical exam-based SODA. Six patients with repeated evaluation exhibited higher scores, along with deterioration documented on other clinical scales. The SODA can reliably predict neurodegeneration as an additional clinical surrogate in MSA., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Neurological soft signs (NSSs), minor physical anomalies (MPAs), and oculomotor abnormalities were plausible biomarkers in bipolar disorder (BD). However, specific impairments in these markers in patients after the first episode mania (FEM), in comparison with first-degree relatives (high risk [HR]) of BD and healthy subjects (health control [HC]) are sparse., Aim of the Study: This study aimed at examining NSSs, MPAs, and oculomotor abnormalities in remitted adult subjects following FEM and HR subjects in comparison with matched healthy controls. Investigated when taken together, could serve as composite endophenotype for BD., Methods: NSSs, MPAs, and oculomotor abnormalities were evaluated in FEM ( n  = 31), HR ( n  = 31), and HC ( n  = 30) subjects, matched for age (years) ( p  = 0.44) and sex ( p  = 0.70) using neurological evaluation scale, Waldrop's physical anomaly scale and eye tracking (SPEM) and antisaccades (AS) paradigms, respectively., Results: Significant differences were found between groups on NSSs, MPAs, and oculomotor parameters. Abnormalities are higher in FEM subjects compared to HR and HC subjects. Using linear discriminant analysis, all 3 markers combined accurately classified 72% of the original 82 subjects (79·2% BD, 56·70% HR, and 82·1% HC subjects)., Conclusions: AS and SPEM could enhance the utility of NSSs, and MPAs as markers for BD. The presence of these abnormalities in FEM suggests their role in understanding the etiopathogenesis of BD in patients who are in the early course of illness. These have the potential to be composite endophenotypes and have further utility in early identification in BD., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: To clarify the clinical features of patients with Double seronegative (DS) ocular myasthenia gravis (OMG)., Methods: Sixty-one patients diagnosed with DS OMG at the Department of Ophthalmology, Hyogo Medical University Hospital over a 5-year period from 2017 were included. Patients were classified into three groups based on the initial examination findings: group P (ptosis alone), group M (ocular motility disorder alone), and group PM (combination of both). We retrospectively reviewed the patients and clarified their clinical features., Results: There were 32 males and 29 females, with a mean age of 49.8 ± 20.9:1-82 years. Twenty-one patients (34.4%) were in group P, 23 (37.7%) in group M, and 17 (27.8%) in group PM. The proportion of males (73.9%) was significantly higher in group M compared with the other two groups. The diagnosis was proven by detection of neuromuscular junction (NMJ) disorder in 73.8%, oral pyridostigmine trial test in 13.1%, and eight patients (13.1%) in group M were diagnosed after surgical treatment. The clinical symptoms were resolved by oral pyridostigmine treatment in 54.1% of cases., Conclusion: About 30% of patients with DS OMG had no obvious NMJ disorder, and an oral pyridostigmine trial test was necessary to diagnose these patients. Although DS OMG is often considered as the mildest form of MG, its prognosis is not optimistic and it requires aggressive therapeutic intervention., Trial Registration: Trial registration number: 202104-750, "2016/4/18," retrospectively registered., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Clinical Features: The click phenomenon occurs when an acquired mechanical restriction of the elevation in adduction of the eye or of the extension of the finger/thumb, is forcefully overcome. The common cause is a nodule either of the superior oblique tendon posterior to the trochlea in the case of a Jaensch-Brown syndrome or of the digital flexor tendon anterior to the A1 annular pulley in the case of a trigger finger. Both locations share similar anatomical conditions for the development of the nodule and the pathomechanism of the click., Results: From these identical findings in the eye and the hand in small children it can be assumed that the results from the studies of the hand in newborns and infants with a trigger thumb/finger are also applicable to the situation of the eye. 1. This motility disorder is not congenital. This is most likely due to an incomplete development at the time of birth of the sliding factors needed for a free passage of the tendon through the trochlea and the A1 annular pulley. 2. A distinction must be made between stages 0-3: stage 0 = no more restriction of the motility and no click phenomenon; stage 1 = forced active extension/elevation possible; stage 2 = only passive extension/elevation, each with a click phenomenon; stage 3 = no extension/elevation possible and no click phenomenon. 3. In most cases in early childhood there is a spontaneous complete recovery (75% after 6-7 years). In the eye this spontaneous course can only limitedly be shortened with motility exercises in combination with segmental occlusion., Conclusion: The click phenomenon is a symptom of stages 1 and 2 of an acquired mechanical restriction of the elevation in adduction of the eye or the extension of the finger/thumb. It should not be called a syndrome., (© 2024. The Author(s).)

Clinical Significance: Understanding the refractive profile, amblyopia prevalence, binocular status, and head position in patients with Brown syndrome help clinicians become more familiar with this syndrome., Background: Brown syndrome is identified as an active and passive restricted elevation of the eye in adduction. There is little information on clinical features, including refractive status, amblyopia, abnormal head posture (AHP), and types of deviation in these patients., Methods: This study retrospectively evaluated records of 100 Brown syndrome patients from 2015 to 2022 at Farabi Eye Hospital, Iran., Results: The mean age was 6.99 ± 6.33 years, including 48 (48%) males. A congenital source was found in 74 (74%) and 96 (96%) patients had unilateral involvement. The mean CDVA for the affected and non-affected eyes were 0.05 ± 0.11 and 0.03 ± 0.06 logMAR, respectively ( P  = 0.31). In unilateral cases, hyperopia, myopia, and emmetropia were observed in 55 (57.29%), 2 (2.08%), and 39 (40.63%) affected eyes, respectively. The most common type of deviation was pure hypotropia, which was found in 53 (53%) cases, followed by 'combined exotropia and hypotropia' observed in 26 (26%) patients. The mean angle of hypotropia and horizontal deviation in the primary position at distance was 12.10 ± 8.50 and 8 ± 13.20 prism dioptre, respectively. A V-pattern was found in 76 (76%) patients. Amblyopia was observed in 13 (21.67%) of 60 cooperative patients, and AHP was noticed in 66 (66%) patients, in which "combined chin up and contralateral face turn" was the most common type., Conclusion: About 75% of cases were congenital, 50% had pure hypotropia, 75% showed V-pattern, 20% had amblyopia, and AHP was observed in 67% of patients. The remarkable prevalence of amblyopia alongside the high occurrence of AHP should alert clinicians to carefully assess patients with Brown syndrome for sensory fusion and amblyopia.

Congenital fibrosis of the extraocular muscles (CFEOM) type 1 is associated with heterozygous missense variants in KIF21A, which encodes a kinesin-like motor protein. Individuals with CFEOM1 have severe paralysis of upgaze and ptosis, resulting in a pronounced chin-up head posture. There can also be limitations of horizontal eye movements. Loss of function of KIF26A, an unconventional kinesin motor protein that lacks ATP-dependent motor activity, has been recently reported to cause a spectrum of congenital brain malformations associated with defects in migration, localization, and growth of excitatory neurons. It has also been associated with megacolon resembling Hirschsprung's disease. We report the case of a boy with homozygous loss of function of KIF26A with restricted eye movements, specifically restricted upgaze and downgaze with variable nystagmus and dissociated vertical eye movements. This case represents a congenital cranial dysinnervation disorder, most similar to CFEOM, and is the first report of a congenital cranial dysinnervation disorder caused by a kinesin other than KIF21A., (Copyright © 2024 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.)

In patients with cerebellar ataxia (CA), symptoms related to oculomotor dysfunction significantly affect quality of life (QoL). This study aimed to analyze the literature on patient-related outcome measures (PROMs) assessing QoL impacts of vestibular and cerebellar oculomotor abnormalities in patients with CA to identify the strengths and limitations of existing scales and highlight any areas of unmet need. A systematic review was conducted (Medline, Embase) of English-language original articles reporting on QoL measures in patients with vertigo, dizziness or CA. Pre-specified parameters were retrieved, including diseases studied, scales applied and conclusions drawn. Our search yielded 3671 articles of which 467 studies (n = 111,606 participants) were deemed relevant. The most frequently studied disease entities were (a) non-specific dizziness/gait imbalance (114 studies; 54,581 participants), (b) vestibular schwannomas (66; 15,360), and (c) vestibular disorders not further specified (66; 10,259). The Dizziness Handicap Inventory (DHI) was the most frequently used PROM to assess QoL (n = 91,851), followed by the Penn Acoustic Neuroma Quality-of-Life Scale (n = 12,027) and the Activities-Specific Balance Confidence Scale (n = 2'471). QoL-scores capturing symptoms related to oculomotor abnormalities in CA were rare, focused on visual impairments (e.g., National-Eye-Institute Visual Function Questionnaire, Oscillopsia Functional Impact, oscillopsia severity score) and were unvalidated. The DHI remains the most widely used and versatile scale for evaluating dizziness. A lack of well-established PROMs for assessing the impact of oculomotor-related symptoms on QoL in CA was noted, emphasizing the need for developing and validating a new QoL-score dedicated to the oculomotor domain for individuals with CA., (© 2024. The Author(s).)

Objective: To document (1) oculomotor (OM) and vestibulo-ocular (VO) function in children with concussion who were symptomatic at the time of assessment and to compare it with that in children with concussion who were clinically recovered (asymptomatic) and in children with no concussive injury, and (2) the extent to which OM and VO function relates to postconcussion symptom severity in injured children., Setting: Participants were recruited from a concussion clinic or the community., Participants: A total of 108 youth with concussion (72 symptomatic; 36 recovered) and 79 healthy youth (aged 9-18 years). Youth with concussion were included if aged 9 to 18 years, had no previous concussion within the last 12 months, less than 90 days since injury, and no known existing visual disorders or learning disabilities., Study Design: A prospective cross-sectional study., Main Measures: All participants were tested for OM and VO function with a commercial virtual reality (VR) eye-tracking system (Neuroflex ® , Montreal,Québec, Canada). Participants in the concussion group who completed the postconcussion symptoms were scored with the Post-Concussion Symptom Inventory., Results: There was a significant group effect for vergence during smooth pursuit ( F2,176 = 10.90; P < .05), mean latency during saccades ( F2,171 = 5.99; P = .003), and mean response delay during antisaccades ( F2,177 = 9.07; P < .05), where children with symptomatic concussion showed poorer performance than clinically recovered and healthy children. Similar results were found in VO for average vestibular ocular reflex gain in the horizontal leftward ( F2,168 = 7; P = .001) and rightward directions ( F2,163 = 13.08; P < .05) and vertical upward ( F2,147 = 7.60; P = .001) and downward directions ( F2,144 = 13.70; P < .05). Mean saccade error was positively correlated to total Post-Concussion Symptom Inventory scores in younger clinically recovered children., Conclusion: VR eye tracking may be an effective tool for identifying OM and VO deficits in the subacute phase (<90 days) postconcussion., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Reading fluency deficits in schizophrenia (Sz) have been attributed to dysfunction in both lower-level, oculomotor processing and higher-level, lexical processing, according to the two-hit deficit model. Given that prior work examining reading deficits in individuals with Sz has primarily focused on single-line and single-word reading tasks, eye movements that are unique to passage reading, such as return-sweep saccades, have not yet been examined in Sz. Return-sweep saccades are large eye movements that are made when readers move from the end of one line to the beginning of the next line during natural passage reading. Examining return-sweeps provides an opportunity to examine lower-level, oculomotor deficits during reading under circumstances when upcoming higher-level, lexical information is not available for visual processing because visual acuity constraints do not permit detailed lexical processing of line-initial words when return-sweeps are programmed. To examine the source of reading deficits in Sz, we analysed an existing data set in which participants read multi-line passages with manipulations to line spacing. Readers with Sz made significantly more return-sweep targeting errors followed by corrective saccades compared with healthy controls. Both groups showed similar effects of line spacing on return-sweep targeting accuracy, suggesting similar sensitivities to visual crowding during reading. Furthermore, the patterns of fixation durations in readers with Sz corroborate prior work indicating reduced parafoveal processing of upcoming words. Together, these findings suggest that lower-level visual and oculomotor dysfunction contribute to reading deficits in Sz, providing support for the two-hit deficit model., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: To report the change in the magnitude of near exodeviation in children with symptomatic convergence insufficiency successfully treated with office-based vergence/accommodative therapy in the Convergence Insufficiency Treatment Trial-Attention and Reading Trial., Methods: A total of 131 children 9-14 years of age with symptomatic convergence insufficiency classified as successfully treated with office-based vergence/accommodative therapy at the 16-week outcome visit were included. Masked examiners measured the near ocular deviation by the prism and alternate cover test at baseline, primary outcome and 1-year post-treatment. The mean change in near deviation was calculated from baseline to primary outcome, from primary outcome to 1-year post-treatment and from baseline to 1-year post-treatment., Results: Of the 131 participants successfully treated with vergence/accommodative therapy, 120 completed the 1-year post-treatment visit. A significant change in near exodeviation was observed at baseline to primary outcome (2.6Δ less exo, p < 0.001, moderate effect size d = 0.61) and at baseline to 1-year post-treatment (2.0Δ less exo; p < 0.001, small effect size d = 0.45). The change from primary outcome to 1-year post-treatment (0.6Δ more exo; p = 0.06, small effect size d = 0.11) was not significant. Forty per cent (48/120) of participants had a decrease in near exodeviation >3.5∆ (expected test/retest variability) between baseline and the primary outcome examination. Of the 120 participants, one (1.0%) was esophoric at the primary outcome and was subsequently exophoric at 1-year post-treatment. Four participants (3.3%) who were orthophoric or exophoric at the primary outcome were esophoric (all ≤3∆) at the 1-year post-treatment visit., Conclusion: On average, the near exodeviation was smaller in size immediately after the discontinuation of vergence/accommodative therapy (2.6∆, moderate effect size) and 1 year post vergence/accommodative therapy (2.0∆, small effect size) in children with convergence insufficiency who were successfully treated; 40% had a clinically meaningful decrease in exophoria. The development of near esophoria was rare., (© 2024 The Authors. Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)

Significance: Visual midline shifts are thought to occur post-stroke and be a risk factor for falls. This study investigates a new method for quantifying visual midline shifts, a first step toward developing greater understanding of visual midline shift., Purpose: This study standardized the parameters of a novel visual midline gauge, compared the results with the current clinical method, and presents normative data and repeatability of both methods., Methods: Ninety-three participants without neurological or ocular problems were recruited in Canada and Hong Kong. In experiment 1, horizontal and vertical visual midlines were measured using the gauge for two speeds and two repositioning methods. In experiment 2, visual midline was measured for three distances using a target speed and repositioning method chosen based on the first experiment. Visual midlines were also measured using the current clinical method during both visits., Results: There were no significant effects of age, speed, study location, or repositioning method on visual midline positions (all p>0.05). For the horizontal direction, measurements at 25 cm were different from those at 50 (p=0.03) and 100 cm (p=0.001). For the vertical direction, there was no such effect. The measurements were found to be repeatable to within approximately 3°. In both visits, there were significant correlations between measurements using the visual midline gauge and the clinical method for the vertical direction (all p<.001) but not for the horizontal direction (all p>0.05)., Conclusions: The measurement of visual midline is tolerant of differences in target speed, testing method, and age of the participants, and the visual midline gauge measurements are repeatable., Competing Interests: Conflict of Interest Disclosure: None of the authors have reported a financial conflict of interest., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Optometry.)

The diagnosis of ocular motor disorders and the different forms of a nystagmus is based on a systematic clinical examination of all types of eye movements: eye position, spontaneous nystagmus, range of eye movements, smooth pursuit, saccades, gaze-holding function, vergence, optokinetic nystagmus, as well as testing of the function of the vestibulo-ocular reflex (VOR) and visual fixation suppression of the VOR. Relevant anatomical structures are the midbrain, pons, medulla, cerebellum, and cortex. There is a simple clinical rule: vertical and torsional eye movements are generated in the midbrain, horizontal in the pons. The cerebellum is relevant for almost all types of eye movements; typical pathological findings are saccadic smooth pursuit, gaze-evoked nystagmus or dysmetric saccades.Nystagmus is defined as a rhythmic, most often involuntary eye movement. It normally consists of a slow (pathological) drift of the eyes and a fast central compensatory movement of the eyes back to the primary position (re-fixation saccade). There are three major categories: first, spontaneous nystagmus, i. e. nystagmus which occurs in the gaze straight ahead position as upbeat or downbeat nystagmus; second, nystagmus that becomes visible at eccentric gaze only and third, nystagmus which can be elicited by certain maneuvers, e. g. head-shaking, head positioning, air pressure or hyperventilation, most of which are of peripheral vestibular origin. The most frequent central types of spontaneous nystagmus are downbeat and upbeat, infantile, pure torsional, pendular fixation, periodic alternating, and seesaw nystagmus. Many types of central nystagmus allow a precise neuroanatomical localization: for instance, downbeat nystagmus, which is most often caused by a bilateral floccular lesion or dysfunction, or upbeat nystagmus, which is caused by a lesion in the mesencephalon or medulla oblongata. Examples of pharmacotherapy are the use of 4-aminopyridine for downbeat and upbeat nystagmus, memantine or gabapentin for fixation pendular nystagmus or baclofen for periodic alternating nystagmus., Competing Interests: M. Strupp is Joint Chief Editor of the Journal of Neurology, Editor in Chief of Frontiers of Neuro-otology and Section Editor of F1000. He has received speaker’s honoraria from Abbott, Auris Medical, Biogen, Eisai, Grünenthal, GSK, Henning Pharma, Interacoustics, J&J, MSD, NeuroUpdate, Otometrics, Pierre-Fabre, TEVA, UCB, and Viatris. He receives support for clinical studies from Decibel, U.S.A., Cure within Reach, U.S.A. and Heel, Germany. He distributes “M-glasses” and “Positional vertigo App”. He acts as a consultant for Abbott, AurisMedical, Bulbitec, Heel, IntraBio, Sensorion and Vertify. He is investor and share-holder of IntraBio., (Thieme. All rights reserved.)

Oculomotor deficits are common in hereditary ataxia, but disproportionally neglected in clinical ataxia scales and as outcome measures for interventional trials. Quantitative assessment of oculomotor function has become increasingly available and thus applicable in multicenter trials and offers the opportunity to capture severity and progression of oculomotor impairment in a sensitive and reliable manner. In this consensus paper of the Ataxia Global Initiative Working Group On Digital Oculomotor Biomarkers, based on a systematic literature review, we propose harmonized methodology and measurement parameters for the quantitative assessment of oculomotor function in natural-history studies and clinical trials in hereditary ataxia. MEDLINE was searched for articles reporting on oculomotor/vestibular properties in ataxia patients and a study-tailored quality-assessment was performed. One-hundred-and-seventeen articles reporting on subjects with genetically confirmed (n=1134) or suspected hereditary ataxia (n=198), and degenerative ataxias with sporadic presentation (n=480) were included and subject to data extraction. Based on robust discrimination from controls, correlation with disease-severity, sensitivity to change, and feasibility in international multicenter settings as prerequisite for clinical trials, we prioritize a core-set of five eye-movement types: (i) pursuit eye movements, (ii) saccadic eye movements, (iii) fixation, (iv) eccentric gaze holding, and (v) rotational vestibulo-ocular reflex. We provide detailed guidelines for their acquisition, and recommendations on the quantitative parameters to extract. Limitations include low study quality, heterogeneity in patient populations, and lack of longitudinal studies. Standardization of quantitative oculomotor assessments will facilitate their implementation, interpretation, and validation in clinical trials, and ultimately advance our understanding of the evolution of oculomotor network dysfunction in hereditary ataxias., (© 2023. The Author(s).)

Introduction: To study the rare and unusual causes of monocular elevation deficit., Methods: Five patients presenting to us with diplopia and elevation deficit were thoroughly examined and were found to have monocular elevation deficit due to rare causes., Observations: All five were found to have different underlying etiologies - iatrogenic, sphenoid wing meningioma, cysticercosis, sarcoidosis and mid brain infarct, and were managed appropriately., Discussion: Monocular Elevation Deficit can occur due to a variety of causes. Having a high index of suspicion for the more serious etiologies is of utmost importance. Thorough clinical examination and imaging help clinch the diagnosis.

Background and Objectives: With the discovery of the potential role of gait and eye movement disorders in Parkinson's disease (PD) recognition, we intend to investigate the combined diagnostic value of gait and eye movement disorders for PD., Methods: We enrolled some Chinese PD patients and healthy controls and separated them into the training and validation sets based on enrollment time. Performance in five oculomotor paradigms and in one gait paradigm was examined using an infrared eye tracking device and a wearable gait analysis device. We developed and validated a combined model for PD diagnosis via multivariate stepwise logistic regression analysis. Furthermore, subgroup comparisons and multi-model comparison were performed to assess its applicability and advantages., Results: A total of 145 PD patients and 80 healthy controls in China were recruited. The pro-saccade velocity, the trunk-sway max, and the turn mean angular velocity were finally screened out for the model development. Incorporating age factor, the ternary model demonstrated more satisfactory performance on ROC (AUC of 0.953 in the training set and AUC of 0.972 in the validation set), calibration curve, and decision curve. A nomogram was drawn to visualize the model. The combined model outperforms individual models with a broad application and the unique diagnostic value for early detection of PD patients, especially TD-PD patients., Conclusion: We demonstrated the presence of gait and eye movement disorders, as well as the feasibility, applicability, and superiority of employing them together to diagnose PD., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Opsoclonus is a rare disorder characterized by conjugate multidirectional, horizontal, vertical, and torsional saccadic oscillations, without intersaccadic interval, resulting from dysfunction within complex neuronal pathways in the brainstem and cerebellum. While most cases of opsoclonus are associated with autoimmune or paraneoplastic disorders, infectious agents, trauma, or remain idiopathic, opsoclonus can also be caused by medications affecting neurotransmission. This review was prompted by a case of opsoclonus occurring in a patient with Multiple System Atrophy, where amantadine, an NMDA-receptor antagonist, appeared to induce opsoclonus., Methods: Case report of a single patient and systematized review of toxic/drug-induced opsoclonus, selecting articles based on predefined criteria and assessing the quality of included studies., Results: The review included 30 articles encompassing 158 cases of toxic/drug-induced opsoclonus. 74% of cases were attributed to bark scorpion poisoning, followed by 9% of cases associated with chlordecone intoxication. The remaining cases were due to various toxics/drugs, highlighting the involvement of various neurotransmitters, including acetylcholine, glutamate, GABA, dopamine, glycine, and sodium channels, in the development of opsoclonus., Conclusion: Toxic/drug-induced opsoclonus is very rare. The diversity of toxics/drugs impacting different neurotransmitter systems makes it challenging to define a unifying mechanism, given the intricate neuronal pathways underlying eye movement physiology and opsoclonus pathophysiology., Competing Interests: The authors have no competing interests to declare., (Copyright: © 2024 The Author(s).)

Purpose: To describe a rare case of acquired Brown syndrome (ABS) associated with acute rheumatic fever (ARF)., Case Report: a healthy 9-year-old girl developed polyarthritis, carditis, and elevated inflammatory markers 10 days after suffering from a sore throat. She was diagnosed with ARF and was treated with systemic antibiotics and high-dose non-steroidal anti-inflammatory drug (NSAID). After 2 weeks, despite improvement of ARF symptoms, the patient presented with binocular vertical diplopia, periorbital pain, and limited elevation in adduction of the left eye. Imaging revealed a thickened trochlea-superior oblique tendon complex, and ABS due to trochleitis was diagnosed. The patient underwent a successful regional corticosteroid injection as a second-line treatment, and within a month, all signs and symptoms of ABS resolved., Conclusions: ABS is an infrequent yet possible manifestation of ARF., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Disconjugate eye movements are essential for depth perception in frontal-eyed species, but their underlying neural substrates are largely unknown. Lesions in the midbrain can cause disconjugate eye movements. While vertically disconjugate eye movements have been linked to defective visuo-vestibular integration, the pathophysiology and neuroanatomy of horizontally disconjugate eye movements remains elusive., Methods: A patient with a solitary focal midbrain lesion was examined using detailed clinical ocular motor assessments, binocular videooculography and diffusion-weighted MRI, which was co-registered to a high-resolution cytoarchitectonic MR-atlas., Results: The patient exhibited both vertically and horizontally disconjugate eye alignment and nystagmus. Binocular videooculography showed a strong correlation of vertical and horizontal oscillations during fixation but not in darkness. Oscillation intensities and waveforms were modulated by fixation, illumination, and gaze position, suggesting shared visual- and vestibular-related mechanisms. The lesion was mapped to a functionally ill-defined area of the dorsal midbrain, adjacent to the posterior commissure and sparing nuclei with known roles in vertical gaze control., Conclusion: A circumscribed region in the dorsal midbrain appears to be a key node for disconjugate eye movements in both vertical and horizontal planes. Lesioning this area produces a unique ocular motor syndrome mirroring hallmarks of developmental strabismus and nystagmus. Further circuit-level studies could offer pivotal insights into shared pathomechanisms of acquired and developmental disorders affecting eye alignment., (© 2024. The Author(s).)