Visual Dysfunction Research Articles

Vitamin E Mitigates Polystyrene-Nanoplastic-Induced Visual Dysfunction in Zebrafish Larvae

Vitamin E Mitigates Polystyrene-Nanoplastic-Induced Visual Dysfunction in Zebrafish Larvae

FMRI Insights into Visual Cortex Dysfunction as a Biomarker for Migraine with Aura

fMRI Insights into Visual Cortex Dysfunction as a Biomarker for Migraine with Aura

The Comprehensive Systematic Review of Traumatic Brain Injury and Visual Disorders

Background: Traumatic brain injury (TBI) is a leading cause of death and disability globally, affecting predominantly children, young people, and the elderly. Complications include concussions, focal injuries, and diffuse damage. Visual impairments caused by traumatic brain injury can have an influence on quality of life and functional independence. Understanding the relationship between TBI and visual abnormalities is critical for creating effective diagnostic tools and treatment plans. Methods: This systematic review followed PRISMA 2020 guidelines, concentrating solely on full-text articles published in English from 2014 to 2024. Editorials and review articles lacking a DOI were excluded to ensure the use of high-quality sources. A literature review was performed using reputable databases such as ScienceDirect, PubMed, and SagePub to identify pertinent studies. Result: The preliminary database search revealed more than 200 relevant papers on the subject. Following a comprehensive three-stage screening process, eight studies were selected that met the specified inclusion criteria for in-depth analysis. The research were subjected to rigorous critical assessment, enabling an in-depth analysis of traumatic brain injury and visual disorders. This focused approach ensured that the analysis employed strong evidence closely linked with the study's objectives. Conclusion: TBI patients often experience visual dysfunctions, affecting their outcomes. The severity and type of injury significantly influence these issues. Comprehensive eye examinations are crucial for detecting subtle impairments, and long-term monitoring and rehabilitation strategies are essential for improved patient care.

Emulation of the subjective experience of visual dorsal stream dysfunction: a description of three in depth case studies.

These case studies explore the subjective visual experiences of individuals with cerebral visual impairment (CVI), specifically dorsal stream dysfunction (DSD) characterized by simultanagnosia. Through three in-depth case studies, this work documents the challenges these individuals face when navigating cluttered environments. The individuals were asked to describe their visual experiences while watching videos of varying complexity, with the future aim of creating a simulation of simultanagnosia. This process revealed a dynamic constriction of their attentional visual fields as scene complexity increased, and vice versa. Notably, the volunteers experienced a phenomenon where their vision could "get stuck" on specific items, with an apparent concurrent reduction in their ability to perceive and describe visual information as visual clutter increased. These consistent observations indicate that the symptoms of simultanagnosia are not simply limited to perceiving one or two objects at a time but can vary dynamically in response to environmental complexity. They enhance our understanding of how DSD impacts visual search and perceptual experiences, prompting us to propose the term "simultanagnostic vision" to describe this more nuanced and dynamic manifestation of CVI. The results are critical for developing effective interventions and optimizing support strategies for individuals affected by DSD, particularly children at sensitive developmental stages. Furthermore, we recommend deeper investigation into how different visual processing streams in the brain interconnect and influence each other, which may open new avenues for targeted therapeutic interventions.

Thalamic volume differentiates multiple sclerosis from neuromyelitis optica spectrum disorder: MRI-based retrospective study.

Multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD) are distinct demyelinating diseases of the central nervous system, each characterized by unique patterns of motor, sensory, and visual dysfunction. While MS typically affects the brain and spinal cord, NMOSD predominantly targets the optic nerves and spinal cord. This study aims to elucidate the morphometric differences between MS and NMOSD by focusing on gray matter volume changes in specific brain regions. We also examined if temporal changes in follow-up MRI differentiate the two disorders. We analyzed anatomical T1-weighted MRI scans from 24 patients with NMOSD and 25 patients with MS using the CAT12 toolbox. Our analysis revealed significant differences in gray matter structure between the two patient groups. Notably, the thalamus was found to be consistently smaller in patients with MS compared to those with NMOSD. This finding aligns with previous research highlighting thalamic atrophy as a hallmark of MS and further underscores the thalamus's role in the disease's pathology. These results provide valuable insights into the distinct neuroanatomical features of MS and NMOSD, contributing to a better understanding of the mechanisms underlying these diseases. The study also emphasizes the importance of advanced imaging techniques in differentiating between MS and NMOSD, which may have implications for diagnosis and treatment strategies.

Symptom management in melanoma associated retinopathy following intravitreal dexamethasone

Aims/Purpose: Patients with melanoma‐associated retinopathy (MAR) experience visual impairment, which can persist even following remission of the melanoma. Here we report two patients in whom symptoms improved following intravitreal dexamethasone implants.Methods: An 81 year old man reported recent onset visual disturbance. Electroretinograms (ERGs) revealed loss of ON bipolar signals, raising the possibility of MAR. Further investigation revealed metastatic melanoma. The patient underwent treatment, resulting in melanoma remission. The second patient (an 87 year old man) was diagnosed with metastatic melanoma and later developed visual symptoms in his better eye (the other eye had a prior ischaemic retinal vein occlusion). ERGs revealed selective ON bipolar signal loss, consistent with MAR. In both patients, despite systemic melanoma treatment, visual symptoms persisted.Results: The first patient underwent cycles of plasma exchange, but vision continued to deteriorate, with visual acuity reaching 20/120 and 20/600 in right and left eye respectively. In light of prior reports of intravitreal steroids improving some cases of MAR, he underwent intravitreal dexamethasone implants. This was associated with subjective improvement of symptoms as well as improved acuity. Multiple treatments were performed to both eyes, with visual acuity stabilising around 20/80 in both eyes. The second patient found his symptoms of photopsia and impaired colour vision troubling. Visual acuity dropped to 20/40. After one intravitreal dexamethasone implant, symptoms improved markedly, with acuity also improving slightly to 20/30. Both patients remain under review.Conclusions: The cases highlight the importance of considering possible paraneoplastic retinopathy in visual dysfunction and apparently unremarkable examination (in the first case, the symptoms preceded the melanoma diagnosis). The cases add to the few existing case reports of possible benefit from intravitreal steroid in MAR.ReferencesAmeerah Ilyas,1 Jit Kai Tan,1–3 Supawat Trepatchayakorn,2 Edward Bloch,1–3 Anthony G. Robson,1,4 Gordon T. Plant,5 Jonny Virgo,3 Andrew R. Webster,1,2 Carlos Pavesio,1,2 Moin D. Mohamed,3 Omar A. Mahroo1–4 UCL Institute of Ophthalmology Retinal Service, Moorfields Eye Hospital

Postural instability and gait disturbance are associated with abnormal stereopsis in Parkinson's disease.

Visual dysfunction, including abnormal stereopsis, is a significant non-motor symptom in Parkinson's disease (PD) that can reduce quality of life and appears early in the disease. Abnormal stereopsis is associated with worsening of bradykinesia and freezing of gait, though the exact pathways linking stereopsis to motor symptoms remain unclear. Furthermore, in PD patients, the pedunculopontine nucleus and laterodorsal tegmental complex play an active role in sensorimotor control, and these areas provide cholinergic projections. Cholinergic degeneration may be associated with symptoms such as abnormal stereopsis, postural instability, gait disturbances and cognitive impairment. Therefore, in this study, we hypothesized that a high postural instability and gait disturbance score would increase the risk of abnormal stereopsis in PD. We designed a cross-sectional study and included 240 early PD patients without ophthalmologic problems other than abnormal stereopsis. To evaluate stereopsis, we used Titmus stereo test plates. Stereopsis testing was performed only once at the time of the patient's initial PD diagnosis. We collected data from medical history taking, scales, cognitive function tests, gait analysis, and tilt table tests. To analyze the potential risk factors for abnormal stereopsis in PD, we conducted a binary logistic stepwise selection analysis. Among the total of 240 PD patients, 185 were in the normal stereopsis group and 55 were in the abnormal stereopsis group. In the analysis for risk factors related to abnormal stereopsis, the postural instability and gait difficulties (PIGD) subtype score was significantly associated with abnormal stereopsis. (95% confidence interval: 1.37-5.15). In PD, particularly in PIGD subtype patients, abnormal stereopsis can lead to a decrease in the quality of sensory information, potentially interfering with feedback and adaptation processes. This, in turn, can negatively affect posture and gait, creating a vicious cycle.

Isolated ocular involvement in acute lymphoblastic leukemia with optic nerve infiltration: An indicator of relapse! - Case series

The ophthalmic evaluation may indicate early relapses of acute lymphoblastic leukemia (ALL) even in the presence of normal cerebrospinal fluid (CSF) cytology, blood, and bone marrow parameters. A high degree of suspicion in patients having visual dysfunction in ALL may help in early diagnosis and prompt initiation of treatment. We present a case series of five ALL patients with optic nerve head (ONH) involvement as the first sign of central nervous system (CNS) relapse with normal CSF, blood, and bone marrow parameters Though it is difficult to objectively specify a window period during which initiation of treatment can maximize the chances of visual recovery, we can emphasize that prompt initiation of treatment (preferably not exceeding more than a week interval) might have a more favorable visual outcome. We present a case series of five ALL patients with ONH involvement as the first sign of CNS relapse with normal CSF, blood, and bone marrow parameters.

Co-occurrence of Parkinson's disease and Retinitis Pigmentosa: A genetic and in silico analysis.

Parkinson's disease (PD) is primarily driven by the protein Alpha Synuclein (A-Syn) accumulation. Synphilin-1 protein, encoded by the SNCAIP gene, which co-localizes with A-Syn is a known risk factor for PD. Retinitis pigmentosa (RP), is a cluster of retinal degenerative disorders, and Cyclic Nucleotide Gated channel subunit Alpha 1 (CNGA1) is one of the initial genes associated with RP. Patients with PD can have various kinds of visual dysfunction as a non-motor manifestation, but to date, CNGA1 mutation and RP as a PD associated visual symptom has not been reported. We report a mutation in the SNCAIP gene in a PD patient, not reported earlier, and its co-occurrence with RP-associated CNGA1 gene mutation. Whole exome sequencing (WES) of the patient DNA sample and in-silico protein-protein interaction (PPI) analysis performed to find out proteins interacting with SNCAIP relevant concerning reported mutation of SNCAIP and further, CNGA1 interaction with SNCAIP. We are reporting, a missense mutation (p.Thr64Ser) at the SNCAIP gene, co-occurring with a missense variation (p.Gly509Arg) in the CNGA1 gene. In silico PPI analysis suggests SIAH1 as an important protein affected by SNCAIP mutation. LGALS4 and SNCA (gene encoding A-Syn) are common interactors between SNCAIP and CNGA1. The current study has determined the co-occurrence of RP and PD, whole exome sequencing ascertains the mutations in SNCAIP and CNGA1 genes, which could be the cause of PD and RP co-occurrence.

Multimodal Longitudinal Optical Imaging Reveals Optic Neuritis Preceding Retinal Pathology in Experimental Autoimmune Encephalomyelitis.

Inflammatory demyelinating diseases of the CNS, chief among them multiple sclerosis (MS), are a major cause of disability in young adults. Early manifestations of MS commonly involve visual dysfunction, which is often caused by optic neuritis and is accompanied by quantifiable structural changes of the anterior visual pathway. Retinal optical coherence tomography (OCT) has emerged as an important tool for clinical assessment of these structural alterations, but the underlying pathobiological mechanisms and temporal dynamics are yet poorly understood at a cellular level. Using the experimental autoimmune encephalomyelitis (EAE) model of MS in fluorescent reporter mouse strains for neuronal function and innate immune cells, we use a unique combination of retinal intravital 2-photon microscopy (2PM) and OCT. In this fashion, we elucidate the spatiotemporal interplay of functional and structural retinal changes over the course of 1 month after EAE induction, with histopathologic imaging validating main results. While all mice display histologic signs of optic neuritis early after EAE induction and independently of motor symptom severity, retinal signs of neuronal stress and parenchymal immune activation spike well after clinical peak of disease, with no signs of lasting structural damage appearing within 1 month after EAE induction. Thus, local retinal endpoints appear to be functions of downstream axonal damage rather than of immediate immune activation directed at the retina. However, as early as 1 week after EAE induction, retinal 2PM can detect recruitment of perivascular immune cells towards the optic nerve (ON), providing the earliest sign of disease activity in otherwise clinically inconspicuous mice. Our work identifies the recruitment of CX3CR1+ cells to the ON as an early sign of disease underlining the importance of combined structural and functional retinal imaging for the spatiotemporal characterization of neuroinflammatory and neurodegenerative processes. It further proposes retinal phagocyte orientation, morphology, and abundance as potential surrogate markers for neurodegenerative activity.

Artificial intelligence virtual assistants in primary eye care practice.

To propose a novel artificial intelligence (AI)-based virtual assistant trained on tabular clinical data that can provide decision-making support in primary eye care practice and optometry education programmes. Anonymised clinical data from 1125 complete optometric examinations (2250 eyes; 63% women, 37% men) were used to train different machine learning algorithm models to predict eye examination classification (refractive, binocular vision dysfunction, ocular disorder or any combination of these three options). After modelling, adjustment, mining and preprocessing (one-hot encoding and SMOTE techniques), 75 input (preliminary data, history, oculomotor test and ocular examinations) and three output (refractive, binocular vision status and eye disease) features were defined. The data were split into training (80%) and test (20%) sets. Five machine learning algorithms were trained, and the best algorithms were subjected to fivefold cross-validation. Model performance was evaluated for accuracy, precision, sensitivity, F1 score and specificity. The random forest algorithm was the best for classifying eye examination results with a performance >95.2% (based on 35 input features from preliminary data and history), to propose a subclassification of ocular disorders with a performance >98.1% (based on 65 features from preliminary data, history and ocular examinations) and to differentiate binocular vision dysfunctions with a performance >99.7% (based on 30 features from preliminary data and oculomotor tests). These models were integrated into a responsive web application, available in three languages, allowing intuitive access to the AI models via conventional clinical terms. An AI-based virtual assistant that performed well in predicting patient classification, eye disorders or binocular vision dysfunction has been developed with potential use in primary eye care practice and education programmes.

Postoperative Vision-Related Quality of Life After Sphenoid Wing Meningioma Surgery: Impact of Radiomic Shape Features and Age.

Background: Sphenoid wing meningiomas (SWM) frequently compress structures of the optic pathway, resulting in significant visual dysfunction characterized by vision loss and visual field deficits, which profoundly impact patients' quality of life (QoL), daily activities, and independence. The objective of this study was to assess the impact of SWM surgery on patient-reported outcome measures (PROMs) regarding postoperative visual function. Methods: The Visual Function Score Questionnaire (VFQ-25) is a validated tool designed to assess the impact of visual impairment on quality of life. The questionnaire was distributed to a previously published study population in which shape radiomics were correlated with new cranial nerve deficits after SWM surgery. Results: A total of 42 patients (42/74; 56.8%) responded to the questionnaire. Of the 42 patients, 30 were female (71%) and 12 were male (29%). The multivariable analysis demonstrated that lower sphericity reflecting irregular SWM shape was associated with poorer VFQ-25 (OR: 6.8, 95% CI: 1.141.8, p = 0.039), while age was associated with lower VFQ-25 (OR: 27, 95% CI: 2.7-272.93, p = 0.005), too. Analysis of the subcategories of the VFQ-25 revealed significantly reduced general vision (p = 0.045), social functioning (p = 0.045), and peripheral vision (p = 0.017) in those with SWM with low sphericity. Conclusions: The study highlights that SWM surgery impacts postoperative visual function, with age and irregular SWM shape being associated with poorer postoperative VFQ-25 scores. VFQ-25 is a feasible tool to assess vision outcome in SWM surgery and has clinical potential for longitudinal follow-up evaluations. Irregular SWM shape should be considered during preoperative treatment planning and patient consultation regarding functional outcome.

Retinal Degeneration Associated With Biallelic RDH12 Variants: Longitudinal Evaluation of Retinal Structure and Visual Function in Pediatric Patients.

The purpose of this study was to determine the natural history of the photoreceptor disease in a large group of pediatric patients with RHD12-associated Leber congenital amaurosis (RDH12-LCA), to estimate the changes expected over the duration of a clinical trial, and to define the relationship between the photoreceptor loss and visual dysfunction. Forty-six patients representing 36 families were included. The great majority of patients were under the age of 18 years. Patients underwent complete ophthalmic examinations and imaging with various modalities including adaptive optics scanning laser ophthalmoscopy. Visual function was assessed with static and kinetic perimetry, and full-field stimulus test (FST) under dark- and light-adapted conditions. Patients had a severe and early onset retinal degeneration (EORD). Visual acuity losses showed a progression rate of 0.04 logMAR per year. A small foveal island could be retained but showed degeneration over time. Foveal cone sensitivity losses were predictable by the loss of photoreceptors. Peripapillary retina could be retained with no significant progression detectable. Peripapillary rod sensitivity was substantially less than expected from photoreceptor structure pointing to a large improvement potential. FST sensitivities were reliably recordable in pediatric patients and showed a small but significant improvement with age. Locally and globally, loss of rod sensitivity tended to be larger than loss of cone sensitivity. Foveal cones of RDH12-LCA should be targeted with treatments aimed to slow progression, whereas peripapillary rod photoreceptors should be targeted with treatments aimed to improve night vision. Pediatric FST testing may be complicated by age-related maturation of decision making regarding threshold criteria.

Primary Visual Pathway Changes in Individuals With Chronic Mild Traumatic Brain Injury

Individuals with mild traumatic brain injury (TBI) often report vision problems despite having normal visual acuity and fundus examinations. Diagnostics are needed for these patients. To determine if a battery of assessments or machine-learning approaches can aid in diagnosing visual dysfunction in patients with mild TBI. This prospective, observational, case-control study was conducted between May 2018 and November 2021. The study setting was at a level 1 trauma research hospital. Participant eligibility included adult males and females with recorded best-corrected visual acuity and normal fundus examination. Individuals in the case group had a history of mild TBI; controls had no history of TBI. Exclusion criteria included a history of ocular, neurological, or psychiatric disease, moderate-severe TBI, recent TBI, metal implants, age younger than 18 years, and pregnancy. Cases and controls were sex- and age-matched. Data analysis was performed from July 2023 to March 2024. History of mild TBI in the case group. The single-session visit included the Neurobehavioral Symptom Inventory and measurements of oculomotor function, optical coherence tomography, contrast sensitivity, visual evoked potentials, visual field testing, and magnetic resonance imaging. A total of 28 participants (mean [SD] age, 35.0 [12.8] years; 15 male [53.6%]) with mild TBI and 28 controls (mean [SD] age, 35.8 [8.5] years; 19 female [67.9%]) were analyzed. Participants with mild TBI showed reduced prism convergence test breakpoint (-8.38; 95% CI, -14.14 to -2.62; P = .008) and recovery point (-8.44; 95% CI, -13.82 to -3.06; P = .004). Participants with mild TBI also had decreased contrast sensitivity (-0.07; 95% CI, -0.13 to -0.01; P = .04) and increased visual evoked potential binocular summation index (0.32; 95% CI, 0.02-0.63; P = .02). A subset of participants exhibited reduced peripapillary retinal nerve fiber layer thickness, increased optic nerve/sheath size, and brain cortical volumes. Machine learning identified subtle differences across the primary visual pathway, including the optic radiations and occipital lobe regions, independent of visual symptoms. Results of this case-control study suggest that the visual system was affected in individuals with mild TBI, even in those who did not self-report vision problems. These findings support the utility of a battery of assessments or machine-learning approaches to accurately diagnose this population.

A cross-sectional study of fundus lesion characteristics in patients with acute visual impairment caused by COVID-19 infection

To investigate the characteristics of acute visual dysfunction and fundus lesions in patients with COVID-19 pneumonia. A retrospective case series study was conducted. Data from 48 patients (96 eyes) with COVID-19 infection who presented to our ophthalmology department with acute onset visual disturbance between December 5, 2022, and February 28, 2023 were collected. Asymptomatic patients and those who had already recovered were excluded. Data collected included patient demographics, ophthalmic examinations, multicolor imaging (MCI), infrared autofluorescence (IR), spectral-domain optical coherence tomography (OCT), fundus fluorescein angiography (FFA). Of the 48 patients, 15 were male and 33 were female, with a mean age of 32 years. All patients had bilateral involvement. OCT showed hyperreflective signals in the outer plexiform layer and outer nuclear layer of the macular region in all 96 eyes of 48 patients (100%). Additionally, 66 eyes of 33 patients (68.8%) of eyes demonstrated abnormal reflectivity in the ellipsoid and interdigitation zones. MCI revealed petaloid or wedge-shaped hyperreflective areas in the macula in 46 (47.9%) of eyes, corresponding to hyporeflective areas on IR. Cotton-wool spots were observed in the peripapillary or posterior pole area in 54 (56.3%) of eyes. COVID-19 infection can lead to acute, bilateral, symmetric, and widespread retinal damage. Characteristic findings can be observed in ophthalmological examinations such as OCT, MCI, and IR.

Parental visual dysfunction and its associations with early childhood development in a community sample of families in Beijing, China

While research has associated parental visual functions with child vision, little is known about whether parental visual dysfunction is related to early childhood development (ECD) outcomes other than vision. Considering that parents with visual dysfunction conditions may encounter difficulties in engaging in some daily activities, the children of these parents possibly have fewer opportunities to acquire and refine certain ECD skills. This research explores associations between parental visual dysfunction conditions and different ECD outcomes in a community sample of families from Beijing, China. Participants were parents of 2140 young children (44.4% girls; age range = 0.75–63.25 months). Parents reported concerns about their visual dysfunction and responded to the Chinese version of the Ages and Stages Questionnaires, Third Edition (ASQ-C). Family demographics and child health indicators were controlled for as covariates. Analysis of variance (ANOVA) and analysis of covariance (ANCOVA) tests were used to compare group differences in the ASQ-C scores. Logistic regressions were conducted to examine the relative risk of suspected developmental delays in the ECD domains for children with parents with different visual function conditions. Results showed that children whose parents had visual dysfunction scored lower on the gross motor domain. Specifically, children whose parents had visual dysfunction conditions other than myopia had lower scores on the gross-motor and problem-solving domains relative to their counterparts. This group of children was prone to suspected developmental delays in the problem-solving domain. In conclusion, our findings suggest that having parents with visual dysfunction conditions other than myopia may be a risk, potentially compromising ECD in China.

Spectrum of Visual Dysfunction Detected by a Novel Testing Protocol Within a Special School Eye Care Service.

Children with special educational needs are more likely to have vision problems than peers in mainstream education. Reports focus on visual acuity and refraction, overlooking visuoperceptual difficulties, including cerebral visual impairment. This article reports on the feasibility and outcomes of visual function testing performed during in-school visual assessments. A retrospective chart review was undertaken of children participating in a special school vision programme. The testing strategy included acuity, fields, contrast sensitivity, eye movements, accommodation, stereopsis, visual attention, refraction and a parent-completed questionnaire. The testing method was chosen based on the child's ability to engage with testing. 78 cases were identified (mean age 9.6 years). Low vision (worse than 6/19) was identified in 31%. All six tests of visual function were completed by 44% (mean 5.1; range 2-6). The mean number of atypical responses was 1 (range 0-4). Almost half (49%) showed at least one atypical response, most commonly visual attention (35%) and 25% had atypical eye movements. Overall, only 20% of children in the special school setting demonstrated a normal response to each test they were able to complete. Acuity testing alone does not demonstrate the atypical visual function of a child with special needs. Using techniques which require minimal cognitive, speech or motor function, a range of visual functions can be elicited during in-school testing. This testing strategy has the advantage of demonstrating areas of visual (dys)function impacting on the child's ability to access learning which can be immediately fed back to teaching staff and carers.

Abnormal visual cortex activity using functional magnetic resonance imaging in treatment resistant photophobia in Friedreich Ataxia

PurposeFriedreich ataxia (FDRA) is a debilitating neurodegenerative disease that can have ophthalmological manifestations including visual dysfunction, nystagmus, and optic atrophy. However, severe photophobia has not been reported nor evaluated with functional magnetic resonance imaging (fMRI). MethodsA 64-year-old white female with a 37-year history of FDRA presented to the eye clinic with worsening photophobia of 3 years. To measure her visual cortex activation and subjective responses during episodes of photophobia, she underwent event-related fMRI with light stimuli. In comparison, the same protocol was conducted in an individual with photophobia but without FDRA. After the fMRI, both patients were treated with 35 units of BoNT-A applied to the forehead. ResultsAnalysis of visual cortex activity in response to light stimulus in the FDRA patient showed no correlation between blood oxygen level dependent (BOLD) activation and light stimuli in the first (r = −0.100, p = 0.235), and a weak negative correlation in the second half of the fMRI scan (r = −0.236 p = 0.004). In notable contrast, significant positive correlations were noted between visual cortex activity and the light stimulus (1st half: r = 0.742, p < 0.001, vs. 2nd half: r = 0.614, p < 0.001) in the comparator. Six weeks later, no improvement in photophobia was noted in either patient. ConclusionOur study highlights photophobia as one potential ocular manifestation of FDRA and suggests that one underlying contributor may be a decoupled cortical neurovascular response to light. Our study provides novel information that may guide physiologic understanding and future treatments in this disease.

Deciphering the Physical Characteristics of Ophthalmic Filters Used in Optometric Vision Therapy.

This paper aimed to measure and characterize eleven monochromatic filters and twenty-two combinations used empirically to treat patients with visual dysfunctions to propose enhanced protocols based on solid evidence. Their wavelength, transmittance, and relative sensitivity were defined on the retinal cone cells. A double-beam UV-VIS-NIR spectrophotometer, VARIAN brand, Cary 5000 model, owned by the National Center of Metrology, with high precision and accuracy, was used to characterize all filters. Filters were purchased from Optomatters Corporation, Belgium. When two or three filters are combined, their transmittance and relative sensitivity on the retinal cone cells decrease regardless of wavelength. As a result, the efficiency of combined filters may decrease during treatments. Additionally, most filters and combinations, regardless of the wavelength, transmit a considerable percentage of light from the red spectrum. A depressant is the best monochromatic filter, and Upsilon-Neurasthenic is the strongest combination to stimulate blue cone cells. In contrast, Stimulant and Delta-Theta are best for red and green cone cells. Mu-Delta and Mu-Theta can be interchangeable, as well as Alpha-Delta and Alpha-Theta. Results suggest that the current phototherapy treatment protocol must be deeply revised, and the number of filters and combinations should be reduced to reduce costs and time and boost efficiency.

Visual dysfunction of superior colliculus and lateral geniculate nucleus in idiopathic blepharospasm

BackgroundThe etiology and pathophysiology of idiopathic blepharospasm (BP) are still largely unknown. It has been hypothesized that BP is the consequence of a dysfunction of the basal ganglia loop, although cortical areas, cerebellum, and other brainstem structures may be involved. There is some evidence that the superior colliculus (SC), a sensorimotor brainstem structure, is involved in another adult-onset focal dystonia, the cervical dystonia. To date, there is no data concerning the implication of the SC in BP. ObjectivesOur study aims to investigate the role of the SC in people with idiopathic BP compared to controls using fMRI and a visual stimulation paradigm based on luminance contrast variations. MethodsPeople with idiopathic BP and controls underwent brain fMRI using a standardized protocol, allowing modulation of visual activity in the SC, the lateral geniculate nucleus (LGN), and the primary visual cortex (V1), at increasing luminance levels (1 %, 3 %, 5 %, 9 %). ResultsTen BP women and ten sex- and age-matched controls were enrolled. Compared to controls, the BP group showed no modulation of visual responses at all luminance levels (p < 0.05) in both SC and LGN. In BP, BOLD responses in V1 were significantly lower at 5 % (p = 0.001), and 9 % (p = 0.002) luminance level. ConclusionsOur findings support the concept of SC and LGN dysfunction in idiopathic BP. Brain fMRI, targeting these sub-cortical visual structures, could play a future important role both as a biomarker and in our understanding of the pathophysiology of adult-onset focal dystonias.