Red and green defocus curves and duochrome test in different age groups / Curvas de desenfoque rojo y verde y prueba de duocromo en diferentes grupos de edad

Purpose: To compare the eye defocus curves (DCs) obtained with stimuli on red, green, and white backgrounds and to investigate the applicability of the duochrome test (DT) in different age groups. Methods: 12 elderly (ELD: 59.3 ± 3.9 years) and 8 young (YG: 22.1 ± 1.1 years) subjects were recruited. An optometric assessment with the DT was carried out to obtain the subjective refraction at distance. DCs at distance on green, white, and red backgrounds were measured and the following parameters were deduced: dioptric difference between red-green, green-white, red-white focal positions (minima of the DCs), best corrected visual acuity (BCVA), and widths of the DCs for red, green, and white. Results: The DC difference between the green-white focal positions (mean ± standard deviation) was -0.12±0.17 diopters (D) (ELD, p = 0.012) and -0.11±0.12 D (YG, p = 0.039), while the red-white difference was not statistically significant. The DC red-green difference was 0.20±0.16 D (ELD, p = 0.002) and 0.18±0.18 D (YG, p = 0.008). The ELD BCVA with green background was significantly worse than BCVA with red (p = 0.007) and white (p = 0.007). The mean value of the DC's width in ELD for green (1.01±0.36 D) was higher than for red (0.77±0.21 D) and for white (0.84±0.35 D), but with no statistical significance. Conclusion: Both age groups showed a slight focusing preference for red when using white light. Moreover, ELD showed a worse BCVA with a green compared to a red background. Despite these results deduced by DC analyses, these aspects do not compromise the possibility of using the DT in clinical practice both in the young and in the elderly. Furthermore, the difference of about 0.20 D between red-green DC in both groups confirms the clinical appropriateness of the widespread use of 0.25 D step as the standard minimum difference in power between correcting lenses.(AU)

Narcolepsy and rapid eye movement sleep.

Since the first description of narcolepsy at the end of the 19th Century, great progress has been made. The disease is nowadays distinguished as narcolepsy type 1 and type 2. In the 1960s, the discovery of rapid eye movement sleep at sleep onset led to improved understanding of core sleep-related disease symptoms of the disease (excessive daytime sleepiness with early occurrence of rapid eye movement sleep, sleep-related hallucinations, sleep paralysis, rapid eye movement parasomnia), as possible dysregulation of rapid eye movement sleep, and cataplexy resembling an intrusion of rapid eye movement atonia during wake. The relevance of non-sleep-related symptoms, such as obesity, precocious puberty, psychiatric and cardiovascular morbidities, has subsequently been recognized. The diagnostic tools have been improved, but sleep-onset rapid eye movement periods on polysomnography and Multiple Sleep Latency Test remain key criteria. The pathogenic mechanisms of narcolepsy type 1 have been partly elucidated after the discovery of strong HLA class II association and orexin/hypocretin deficiency, a neurotransmitter that is involved in altered rapid eye movement sleep regulation. Conversely, the causes of narcolepsy type 2, where cataplexy and orexin deficiency are absent, remain unknown. Symptomatic medications to treat patients with narcolepsy have been developed, and management has been codified with guidelines, until the recent promising orexin-receptor agonists. The present review retraces the steps of the research on narcolepsy that linked the features of the disease with rapid eye movement sleep abnormality, and those that do not appear associated with rapid eye movement sleep.

Ophthalmologists' perspectives on corneal transplantation and donation: a survey from Türkiye.

PURPOSE: To evaluate ophthalmologists' interest and opinions regarding corneal transplantation and donation in Türkiye. MATERIAL AND METHODS: An online questionnaire was prepared using Google Forms, and the electronic link to this questionnaire was sent via WhatsApp to ophthalmologists working in Türkiye. Eighteen open-ended/multiple-choice questions were asked about ophthalmologists' demographic information and their opinions regarding corneal transplantation and donation. The answers were analyzed by transferring the data to Excel. RESULTS: A total of 195 ophthalmologists participated in the survey. While 68.6% of them stated that they wanted to donate their corneas, 21.1% stated that they were undecided, and 10.3% did not want to donate their corneas. While 93.8% of the participants agreed to have a cornea transplant in case of need, 5.7% of them stated that they were undecided, and 0.5% said that they would not accept a cornea transplant. The most frequent (90.5%) reason for being willing to donate one's cornea was to give hope to patients with low vision. The most frequent (46.2%) reason for not wanting to donate one's cornea was the unwillingness to have one's body/eye integrity impaired. The vast majority (80.8%) of the participants thought that there was not enough corneal donation in Türkiye and that this was mostly (85.9%) due to cultural and/or religious reasons. CONCLUSIONS: Even in a sample with a high level of education and the most knowledge about corneal transplantation, the willingness to donate corneas may remain below the expected rates. Therefore, it is necessary to alleviate unrealistic concerns and prejudices about corneal donation and transplantation.

An early effect of the parafoveal preview on post-saccadic processing of English words.

A key aspect of efficient visual processing is to use current and previous information to make predictions about what we will see next. In natural viewing, and when looking at words, there is typically an indication of forthcoming visual information from extrafoveal areas of the visual field before we make an eye movement to an object or word of interest. This "preview effect" has been studied for many years in the word reading literature and, more recently, in object perception. Here, we integrated methods from word recognition and object perception to investigate the timing of the preview on neural measures of word recognition. Through a combined use of EEG and eye-tracking, a group of multilingual participants took part in a gaze-contingent, single-shot saccade experiment in which words appeared in their parafoveal visual field. In valid preview trials, the same word was presented during the preview and after the saccade, while in the invalid condition, the saccade target was a number string that turned into a word during the saccade. As hypothesized, the valid preview greatly reduced the fixation-related evoked response. Interestingly, multivariate decoding analyses revealed much earlier preview effects than previously reported for words, and individual decoding performance correlated with participant reading scores. These results demonstrate that a parafoveal preview can influence relatively early aspects of post-saccadic word processing and help to resolve some discrepancies between the word and object literatures.

More than meets the eye: Lid and conjunctival injuries in cases of non-sexual assault are frequently accompanied by non-fatal strangulation.

OBJECTIVE: To determine the associations between lid and conjunctival injuries (LACI), non-fatal strangulation (NFS) and domestic family violence (DFV) in non-sexual assault. METHODS: The present study involves an analysis of LACI in a clinical audit of 85 sequential non-sexual assault presentations. RESULTS: LACI was present in 26.9% of non-sexual assault cases, and 47.4% of LACI patients also experienced NFS. LACI was sustained in the context of DFV in 62.9% of cases. Females made up 69.2% of LACI patients, with those between 14 and 29 years most at risk. Children were present in 12.8% of cases, 78.2% of perpetrators were male and 44.9% of patients had previously been assaulted by the same perpetrator. CONCLUSIONS: LACI is frequently associated with NFS and/or DFV. Since NFS increases future homicide attempts and events more than sixfold, LACI is an important signal about a patient's homicide risk, expanding the dimensions of the care needed. Those experiencing LACI during an assault also need to be referred for comprehensive eye examination as soon as possible. With consent, systematic forensic photography of LACI enables its assessment and documentation, which assists the legal process. These conclusions should drive legislative consideration and reform, plus expanded education for clinicians and police.

Australian Nurse Engagement in Eye Care: A National Survey.

Purpose: An estimated 13 million Australians live with one or more chronic eye conditions, with prevalence increasing. Eye care services today and in the future rely on effective workforces, in which nurses play a pivotal role. Despite nurse involvement in eye care, there is no information describing their engagement, deployment, training, and opinion. This paper offers the first review of nurse engagement in eye care in Australia. Methods: We conducted an e-survey on Australian nurse engagement in eye care. Quantitative questions were analysed by descriptive, chi-square and bivariate correlation coefficients with assumed power of 0.80, and significance of p=0.05. Grounded theory, sentiment and saturation analysis extracted key themes, meaning and opinion from the qualitative questions. Results: There were n=238 Australian nurse participants. Results indicated they were satisfied with their role, engaged in a wide range of healthcare and eye care setting and organisations, and adapted to their employer. Task-shifting "to" and "from" nurses was not universally supported but recognised by participants as necessary. Of concern, the results suggested that 68.6% of our participants would exit eye care over the next ten years, with insufficient entry pathways into the field for graduate and early-career nurses. Conclusion: For Australia to meet and sustain eye care services for its population, steps must be taken to improve exposure and entry to the field for students, graduates, and early-career nurses. Strategies to train and prepare nurses for task-shifting are urgently required and the eye care nursing sector must professionalise to achieve positive change.

Predictive Processing During Cue-Outcome Associative Learning in Autistic Children.

PURPOSE: Predictive coding theories posit that autism is characterized by an over-adjustment to prediction errors, resulting in frequent updates of prior beliefs. Atypical weighting of prediction errors is generally considered to negatively impact the construction of stable models of the world, but may also yield beneficial effects. In a novel associative learning paradigm, we investigated whether unexpected events trigger faster learning updates in favour of subtle but fully predictive cues in autistic children compared to their non-autistic counterparts. We also explored the relationship between children's language proficiency and their predictive performances. METHODS: Anticipatory fixations and explicit predictions were recorded during three associative learning tasks with deterministic or probabilistic contingencies. One of the probabilistic tasks was designed so that a fully predictive but subtle cue was overshadowed by a less predictive salient one. RESULTS: Both autistic and non-autistic children based their learning on the salient cue, and, contrary to our predictions, showed no signs of updating in favour of the subtle cue. While both groups demonstrated associative learning, autistic children made less accurate explicit predictions than their non-autistic peers in all tasks. Explicit prediction performances were positively correlated with language proficiency in non-autistic children, but no such correlation was observed in autistic children. CONCLUSION: These results suggest no over-adjustment to prediction errors in autistic children and highlight the need to control for general performance in cue-outcome associative learning in predictive processing studies. Further research is needed to explore the nature of the relationship between predictive processing and language development in autism.

An Analysis of Optic Disc Parameters in Patients with Peripheral Retinal Tears Following Acute Posterior Vitreous Detachment: A Cross-Sectional Study.

Background: To investigate association between optic disc parameters analyzed by optical coherence tomography (OCT) and occurrence of peripheral retinal tears in patients with symptomatic posterior vitreous detachment (PVD). Methods: This cross-sectional study enrolled 75 patients with symptoms of acute PVD, who were allocated into two groups based on whether a peripheral retinal tear occurred or not. Results: When comparing the average retinal nerve fiber layer (RNFL) thickness (µm) between retinal tear and control groups, it was shown that patients with a retinal tear have a significantly higher (87.18 [95% confidence interval (CI), 84.47 to 89.9] vs 81.14 [95% CI, 77.81 to 84.46], P = 0.005) average RNFL thickness. Furthermore, we observed a significant difference (0.13, 0.06 to 0.22 vs 0.07, 0.04 to 0.1, P = 0.036, Mann-Whitney U-test) in the size of cup volume (mm3) between the tear and control groups, respectively. Linear regression showed a significant decrease (P = 0.029) in average RNFL thickness with increasing age, but without a significant difference between the two groups. There was no statistically significant difference between the tear and control groups in terms of rim area, disc area, and average cup-to-disc ratio. Conclusion: Patients with a higher average RNFL thickness and larger cup volume measured by OCT were more prone to develop a peripheral retinal tear. Increased peripapillary average RNFL thickness due to trauma and subsequent inflammation, possibly related to the more adherent posterior hyaloid membrane to the retina, may also indicate strengthened adhesions in the areas of the peripheral retina where retinal tears occur. OCT analysis of the optic nerve head may be used in everyday clinical practice as a predictor of the development of peripheral retinal tears in patients with symptomatic PVD.

The reverse congruency effect elicited by eye-gaze as a function of attention-deficit/hyperactivity disorder symptoms.

Individuals diagnosed with attention deficit/hyperactivity disorder (ADHD) have been found to have impairments in multiple aspects of social cognition, thus including the attentional processing of socially relevant stimuli such as eye-gaze. However, to date, it remains unclear whether only the social-specific but not the domain-general directional components, elicited by eye-gaze are affected by ADHD symptomatology. To address this issue, the present study aimed to investigate the impact of ADHD-like traits on the social-specific attentional processing of eye-gaze. To this purpose, we conducted an online experiment with a sample of 140 healthy undergraduate participants who completed two self-reported questionnaires designed to assess ADHD-like traits, and a social variant of an interference spatial task known to effectively isolate the social-specific component of eye-gaze. To make our research plan transparent, our hypotheses, together with the plans of analyses, were registered before data exploration. Results showed that while the social-specific component of eye-gaze was evident in the sample, no significant correlation was found between this component and the measured ADHD-like traits. These results appear to contradict the intuition that the attentional processing of the social-specific components of eye-gaze may be impaired by ADHD symptomatology. However, further research involving children and clinical populations is needed in order to clarify this matter.

Whole-eye transplantation: Current challenges and future perspectives.

Whole-eye transplantation emerges as a frontier in ophthalmology, promising a transformative approach to irreversible blindness. Despite advancements, formidable challenges persist. Preservation of donor eye viability post-enucleation necessitates meticulous surgical techniques to optimize retinal integrity and ganglion cell survival. Overcoming the inhibitory milieu of the central nervous system for successful optic nerve regeneration remains elusive, prompting the exploration of neurotrophic support and immunomodulatory interventions. Immunological tolerance, paramount for graft acceptance, confronts the distinctive immunogenicity of ocular tissues, driving research into targeted immunosuppression strategies. Ethical and legal considerations underscore the necessity for stringent standards and ethical frameworks. Interdisciplinary collaboration and ongoing research endeavors are imperative to navigate these complexities. Biomaterials, stem cell therapies, and precision immunomodulation represent promising avenues in this pursuit. Ultimately, the aim of this review is to critically assess the current landscape of whole-eye transplantation, elucidating the challenges and advancements while delineating future directions for research and clinical practice. Through concerted efforts, whole-eye transplantation stands to revolutionize ophthalmic care, offering hope for restored vision and enhanced quality of life for those afflicted with blindness.

Ion channel profiles of extraocular motoneurons and internuclear neurons in human abducens and trochlear nuclei.

Introduction: Extraocular muscles are innervated by two anatomically and histochemically distinct motoneuron populations: motoneurons of multiply-innervated fibers (MIF), and of singly-innervated fibers (SIF). Recently, it has been established by our research group that these motoneuron types of monkey abducens and trochlear nuclei express distinct ion channel profiles: SIF motoneurons, as well as abducens internuclear neurons (INT), express strong Kv1.1 and Kv3.1b immunoreactivity, indicating their fast-firing capacity, whereas MIF motoneurons do not. Moreover, low voltage activated cation channels, such as Cav3.1 and HCN1 showed differences between MIF and SIF motoneurons, indicating distinct post-inhibitory rebound characteristics. However, the ion channel profiles of MIF and SIF motoneurons have not been established in human brainstem tissue. Methods: Therefore, we used immunohistochemical methods with antibodies against Kv, Cav3 and HCN channels to (1) examine the human trochlear nucleus in terms of anatomical organization of MIF and SIF motoneurons, (2) examine immunolabeling patterns of ion channel proteins in the distinct motoneurons populations in the trochlear and abducens nuclei. Results: In the examination of the trochlear nucleus, a third motoneuron subgroup was consistently encountered with weak perineuronal nets (PN). The neurons of this subgroup had -on average- larger diameters than MIF motoneurons, and smaller diameters than SIF motoneurons, and PN expression strength correlated with neuronal size. Immunolabeling of various ion channels revealed that, in general, human MIF and SIF motoneurons did not differ consistently, as opposed to the findings in monkey trochlear and abducens nuclei. Kv1.1, Kv3.1b and HCN channels were found on both MIF and SIF motoneurons and the immunolabeling density varied for multiple ion channels. On the other hand, significant differences between SIF motoneurons and INTs were found in terms of HCN1 immunoreactivity. Discussion: These results indicated that motoneurons may be more variable in human in terms of histochemical and biophysiological characteristics, than previously thought. This study therefore establishes grounds for any histochemical examination of motor nuclei controlling extraocular muscles in eye movement related pathologies in the human brainstem.

Eye care service utilization and associated factors among diabetic patients in Africa: A Systematic Review and Meta-Analysis.

Introduction: 'Vision 2020, the Right to Sight', jointly coordinated by the World Health Organization's program for the prevention of blindness and deafness and the international agency for the prevention of blindness, was launched in 1999, however, the initiative faces many challenges to hitting its target. One of the challenges for this is, the absence of comprehensive data regarding eye care service utilization among diabetes mellitus patients in Africa. Therefore, this study was aimed at assessing the prevalence of eye care service utilization and associated factors among adult diabetes mellitus patients in Africa. Methods: This systematic review and meta-analysis was conducted as per the international preferred reporting items for systematic review and meta-analysis protocols (PRISMA) guidelines. Published articles were searched using reputable databases (PubMed, Cochrane Library) and Web searches (Science Direct, African Journals Online, and Google Scholar). Quality appraisal was assessed based on the Joanna Briggs Institute's (JBI) critical appraisal checklist. The extracted data was exported to STATA version 11 (STATA Corp., LLC) for further analysis. Heterogeneity between the results of primary studies was assessed using Cochran's Q chi-square test and quantified with the I2 statistics. Publication bias was assessed by visual inspection of the funnel plot and Egger's regression tests. Results: The database search found 26,966 articles. The pooled prevalence of eye care service utilization among diabetic patients in Africa is found to be 40.92 % (95 % CI: 27.14-54.70, P < 0.001). Good knowledge (POR = 3.57, 95 % CI: 2.67-4.76), good attitude (POR = 5.68, 95 % CI: 4.20-7.68), age greater than 65 years old (POR = 7.11, 95 % CI: 3.86-13.10), urban residence (POR = 5.03, 95 % CI: 2.12-11.96), and disease duration greater than 6 years (POR = 3.81, 95 % CI: 2.25-6.45) were factors associated with eye care service utilization. Conclusion: This meta-analysis revealed that a high proportion of people with diabetes failed to use eye care services. Older age, good knowledge, urban residence and longer duration of illness were found to be the contributing factors for the utilization of eye care services in diabetes mellitus patients. Therefore, by considering the negative impact of low eye care service utilization, it is important to improve the habit of regular screening of the eye into routine assessment of diabetes mellitus follow up targeting patients with older age and longer duration of illness to reduce the magnitude of the problem.

Early cognitive assessment in premature infants: the discriminatory value of eye-tracking vs. Bayley Scales.

Introduction: The testing of visuocognitive development in preterm infants shows strong interactions between perinatal characteristics and cognition, learning and overall neurodevelopment evolution. The assessment of anticipatory gaze data of object-location bindings via eye-tracking can predict the neurodevelopment of preterm infants at the age of 3 years; little is known, however, about the early cognitive function and its assessment methods during the first year of life. Methods: The current study presents data from a novel assessment tool, a Delayed Match Retrieval (DMR) paradigm via eye-tracking was used to measure visual working memory (VWM) and attention skills. The eye-tracking task that was designed to measure infants' ability to actively localize objects and to make online predictions of object-location bindings. 63 infants participated in the study, 39 preterm infants and 24 healthy full term infants - at a corrected age of 8-9 months for premature infants and similar chronological age for full term infants. Infants were also administered the Bayley Scales of Infant and Toddler Development. Results: The analysis of the Bayley scores showed no significant difference between the two groups while the eye-tracking data showed a significant group effect on all measurements. Moreover, preterm infants' VWM performance was significantly lower than full term's. Birth weight affected the gaze time on all Areas Of Interest (AOIs), overall VWM performance and the scores at the Cognitive Bayley subscale. Furthermore, preterm infants with fetal growth restriction (FGR) showed significant performance effects in the eye-tracking measurements but not on their Bayley scores verifying the high discriminatory value of the eye gaze data. Conclusion: Visual working memory and attention as measured via eye-tracking is a non-intrusive, painless, short duration procedure (approx. 4-min) was found to be a significant tool for identifying prematurity and FGR effects on the development of cognition during the first year of life. Bayley Scales alone may not pick up these deficits. Identifying tools for early neurodevelopmental assessments and cognitive function is important in order to enable earlier support and intervention in the vulnerable group of premature infants, given the associations between foundational executive functional skills and later cognitive and academic ability.

Attaining expertise in regional anaesthesia training using a multifactorial approach incorporating deliberate practice.

The most effective way of delivering regional anaesthesia training and the best means of demonstrating competency have not been established. Clinical competency, based on the Dreyfus and Dreyfus lexicon, appears unachievable using current training approaches. Lessons should be taken from the worlds of music, chess, and sports. Modern skills training programmes should be built on an explicit and detailed understanding with measurement of a variety of factors such as perception, attention, psychomotor and visuospatial function, and kinesthetics, coupled with quantitative, accurate, and reliable measurement of performance.

REM sleep breathing: Insights beyond conventional respiratory metrics.

Breathing and sleep state are tightly linked. The traditional approach to evaluation of breathing in rapid eye movement sleep has been to focus on apneas and hypopneas, and associated hypoxia or hypercapnia. However, rapid eye movement sleep breathing offers novel insights into sleep physiology and pathology, secondary to complex interactions of rapid eye movement state and cardiorespiratory biology. In this review, morphological analysis of clinical polysomnogram data to assess respiratory patterns and associations across a range of health and disease is presented. There are several relatively unique insights that may be evident by assessment of breathing during rapid eye movement sleep. These include the original discovery of rapid eye movement sleep and scoring of neonatal sleep, control of breathing in rapid eye movement sleep, rapid eye movement sleep homeostasis, sleep apnea endotyping and pharmacotherapy, rapid eye movement sleep stability, non-electroencephalogram sleep staging, influences on cataplexy, mimics of rapid eye movement behaviour disorder, a reflection of autonomic health, and insights into cardiac arrhythmogenesis. In summary, there is rich clinically actionable information beyond sleep apnea encoded in the respiratory patterns of rapid eye movement sleep.

Emotion processing in concrete and abstract words: evidence from eye fixations during reading.

We replicated and extended the findings of Yao et al. [(2018). Differential emotional processing in concrete and abstract words. Journal of Experimental Psychology: Learning, Memory, and Cognition, 44(7), 1064-1074] regarding the interaction of emotionality, concreteness, and imageability in word processing by measuring eye fixation times on target words during normal reading. A 3 (Emotion: negative, neutral, positive) × 2 (Concreteness: abstract, concrete) design was used with 22 items per condition, with each set of six target words matched across conditions in terms of word length and frequency. Abstract (e.g. shocking, reserved, fabulous) and concrete (e.g. massacre, calendar, treasure) target words appeared (separately) within contextually neutral, plausible sentences. Sixty-three participants each read all 132 experimental sentences while their eye movements were recorded. Analyses using Gamma generalised linear mixed models revealed significant effects of both Emotion and Concreteness on all fixation measures, indicating faster processing for emotional and concrete words. Additionally, there was a significant Emotion × Concreteness interaction which, critically, was modulated by Imageability in early fixation time measures. Emotion effects were significantly larger in higher-imageability abstract words than in lower-imageability ones, but remained unaffected by imageability in concrete words. These findings support the multimodal induction hypothesis and highlight the intricate interplay of these factors in the immediate stages of word processing during fluent reading.

Navigating Visual Challenges: How Parkinson's Disease Alters Cognitive Priorities in Visual Search.

OBJECTIVE: Parkinson's disease (PD) hampers visual search tasks such as reading, driving, and navigation. We examined expectations from past experiences, guiding cognition and contextual priors, on visual search in PD. METHODS: We compared eye movements as PD and healthy participants searched for a hidden object (target) in cluttered real-world scenes. RESULTS: PD participants prolonged fixation on high-probability (high-prior) locations for the target, consistent across expected and unexpected scenario. Such emphasis on contextual visual priors, evidenced by high fixation duration on high-probability areas, was beneficial when the target was at the expected location but presented challenges when the target was situated in an unlikely place. CONCLUSION: This study contributes to understanding how PD impacts visual search behavior and cognitive processing. The findings indicate that PD alters attention allocation and visual processing by affecting the utilization of contextual visual priors. It provides insights for potential interventions targeting visuo-cognitive deficits in PD patients. Published 2024. This article is a U.S. Government work and is in the public domain in the USA.

Gait Analysis and Magnetic Resonance Imaging Characteristics in Patients with Isolated Rapid Eye Movement Sleep Behavior Disorder.

BACKGROUND: Isolated rapid eye movement sleep behavioral disorder (iRBD) can precede neurodegenerative diseases. There is an urgent need for biomarkers to aid early intervention and neuroprotection. OBJECTIVE: The aim is to assess quantitative motor, cognitive, and brain magnetic resonance imaging (MRI) characteristics in iRBD patients. METHODS: Thirty-eight polysomnography-confirmed iRBD patients and 28 age- and sex-matched healthy controls underwent clinical, cognitive, and motor functional evaluations, along with brain MRI. Motor tasks included nine-hole peg test, five-times-sit-to-stand test, timed-up-and-go test, and 4-meter walking test with and without cognitive dual task. Quantitative spatiotemporal gait parameters were obtained using an optoelectronic system. Brain MRI analysis included functional connectivity (FC) of the main resting-state networks, gray matter (GM) volume using voxel-based morphometry, cortical thickness, and deep GM and brainstem volumes using FMRIB's Integrated Registration and Segmentation Tool and FreeSurfer. RESULTS: iRBD patients relative to healthy subjects exhibited a poorer performance during the nine-hole peg test and five-times-sit-to-stand test, and greater asymmetry of arm-swing amplitude and stride length variability during dual-task gait. Dual task significantly worsened the walking performance of iRBD patients more than healthy controls. iRBD patients exhibited nonmotor symptoms, and memory, abstract reasoning, and visuospatial deficits. iRBD patients exhibited decreased FC of pallidum and putamen within the basal ganglia network and occipital and temporal areas within the visuo-associative network, and a reduced volume of the supramarginal gyrus. Brain functional alterations correlated with gait changes. CONCLUSIONS: Subtle motor and nonmotor alterations were identified in iRBD patients, alongside brain structural and functional MRI changes. These findings may represent early signs of neurodegeneration and contribute to the development of predictive models for progression to parkinsonism. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

[The relationship between intraocular pressure and age-related variations in ocular rigidity]. / Vzaimosvyaz' vnutriglaznogo davleniya s involyutsionnymi kolebaniyami rigidnosti glaza.

PURPOSE: This study aimed to identify the correlation between age-related fluctuations in the average values of rigidity of the fibrous tunic of the eye (FTE) and corresponding ranges of true intraocular pressure (IOP) in healthy eyes and eyes with open-angle glaucoma (OAG); using the identified ranges of FTE rigidity, to establish the appropriate IOP zones for healthy and glaucomatous eyes, taking into account the aging periods as classified by the World Health Organization (WHO). MATERIAL AND METHODS: Ocular-Response Analyzer tonometry was used according to the Koshits-Svetlova dynamic diagnostic method to examine 674 patients with healthy eyes and 518 patients with glaucomatous eyes, aged 18 to 90 years, classified according to the WHO aging periods, and a theoretical analysis was conducted to estimate clinical values of FTE rigidity, the current level of true IOP, and the calculated individual IOP level in a patient's eye during youth. RESULTS: The following IOP level zones were identified for patients with healthy and glaucomatous eyes: low IOP zone (≤13 mm Hg); medium IOP zone (14-20 mm Hg); elevated IOP zone (21-26 mm Hg); high IOP zone (27-32 mm Hg); subcompensated IOP zone (33-39 mm Hg); and decompensated IOP zone (≥40 mm Hg). CONCLUSION: The fundamental physiological criterion "rigidity" does not depend on central corneal thickness and consistently reflects the current level of true IOP. In all examined patients, both with healthy and glaucomatous eyes, healthy and glaucoma eyes with the same level of current rigidity had the same level of IOP. The ability to assign a given healthy or glaucomatous eye to a specific individual IOP zone is particularly important for the polyclinic system.

[Changes in the precorneal tear film at various stages of keratoconus]. / Izmenenie prekorneal'noi sleznoi plenki pri razlichnykh stadiyakh keratokonusa.

The combination of keratoconus (KC) with signs of dry eye disease (DES) has been described in numerous scientific publications. At the same time, there is a relationship between KC stage and an increase in the severity of DES symptoms, however, there is still no common understanding of the severity of xerotic process depending on the clinical course of keratectasia. PURPOSE: This study assesses the changes in the state of the precorneal tear film in KC relative to the stages of the disease. MATERIAL AND METHODS: The study included 50 patients (100 eyes) with bilateral non-operated KC from subclinical to stage IV. The following methods were used for a comprehensive assessment of the condition of the tear film: biomicroscopy of the anterior segment of the eye using vital dyes, functional tests (Norn, Schirmer, Jones tests), tearscopy of the lipid layer of the tear film with software processing of the results, OCT-meniscometry, as well as filling out the OSDI questionnaire by patients. RESULTS: The following significant changes were revealed as the KC stage progressed: an increase in the area of staining of the ocular surface with vital dyes, a decrease in the results of the Norn functional test and OCT-meniscometry, an increase in the areas of smaller thickness of lipids and areas of their complete absence according to tearscopy, as well as an increase in scores of the OSDI questionnaire. CONCLUSION: A comprehensive assessment of the condition of the tear film in KC indicates the relationship and the strengthening of the signs of DES as keratectasia progresses, and can be considered as justification for the need to prescribe tear replacement and reparative therapy that improves the condition of the ocular surface and stabilizes the precorneal tear film.