Homonymous Visual Field Defects Research Articles

Recovery From Homonymous Hemianopia in Hyperglycemia-Induced Occipital Lobe Electroclinical Seizures Following Glycemic Control.

Visual changes due to hyperglycemia in diabetes are not uncommon. While blurred vision is a well-established sequela of chronic hyperglycemia, homonymous hemianopia with or without electroclinical seizures is much rarer and can be mistaken for migraine, temporal arteritis, or ischemia of the central nervous system. This article analyzed case studies for 3 patients (67M, 68M, 52F) presenting with complex visual phenomena, from 3 to 42 days duration, including pathogenesis, clinical findings, management, and follow-up. Examinations demonstrated dense left homonymous hemianopias in 2 patients and a left inferior homonymous quadrantanopia in one, with no other abnormalities. Patients described vivid, nonstereotyped intermittent hallucinations in the affected fields. Blood glucose levels ranged from 13.5 to 35.0 mmol/L (243-630 mg/dL) without ketosis and HbA1c from 14.6% to 16.8%. Computed tomography of the brain showed no acute intracranial pathology. MRI of the brain either detected no abnormalities or demonstrated changes consistent with seizure activity. Electroencephalogram (EEG) demonstrated seizures over the right occipital region in each patient. EEG seizures coincided with patients' hallucinations, while they remained otherwise conscious. Oral hypoglycemic and antiepileptic medications were commenced with rapid and complete reversal of the seizures and visual field deficits, confirmed by repeat Automated 30-2 and MRI. Hyperglycemia-induced occipital lobe seizures with visual hallucinations and interictal homonymous visual field defects represent a rare but clinically important diagnosis. This article highlights the importance of prompt recognition and treatment to facilitate recovery.

Reading Difficulties in Individuals with Homonymous Visual Field Defects: A Systematic Review of Reported Interventions.

Reading difficulties are amongst the most commonly reported problems in individuals with homonymous visual field defects (HVFDs). To be able to provide guidance for healthcare professionals considering offering reading training, researchers in this field and interested individuals with HVFDs, this systematic review aims to (1) provide an overview of the contextual and intervention characteristics of all published HVFD interventions and (2) generate insights into the different reading outcome measures that these studies adopted. A search on PsycINFO, MEDLINE and Web of Science was conducted up to February 2, 2023. All intervention studies for HVFD in which reading was measured were included. Data was collected about the intervention type, session duration, number of sessions, the intensity, duration, circumstance of the interventions, country in which the intervention was studied and reading measures. Sixty records are included, describing 70 interventions in total of which 21 are specifically reading interventions. Overall, adjusted saccadic behaviour interventions occur most in the literature. A wide range within all intervention characteristics was observed. Forty-nine records reported task-performance reading measures, and 33 records reported self-reported reading measures. The majority of task-performance measures are based on self-developed paragraph reading tasks with a time-based outcome measure (e.g. words per minute). Future research could benefit from making use of validated reading tests, approaching the measurement of reading mixed-methods and providing participants the possibility to supply outcomes relevant to them.

The effects of occipital and parietal tDCS on chronic visual field defects after brain injury.

Homonymous visual field defects (HVFDs) following acquired brain lesions affect independent living by hampering several activities of everyday life. Available treatments are intensive and week- or month-long. Transcranial Direct current stimulation (tDCS), a plasticity-modulating non-invasive brain stimulation technique, could be combined with behavioral trainings to boost their efficacy or reduce treatment duration. Some promising attempts have been made pairing occipital tDCS with visual restitution training, however less is knows about which area/network should be best stimulated in association with compensatory approaches, aimed at improving exploratory abilities, such as multisensory trainings. In a proof-of-principle, sham-controlled, single-blind study, 15 participants with chronic HVFDs underwent four one-shot sessions of active or sham anodal tDCS applied over the ipsilesional occipital cortex, the ipsilesional or contralesional posterior parietal cortex. tDCS was delivered during a compensatory multisensory (audiovisual) training. Before and immediately after each tDCS session, participants carried out a visual detection task, and two visual search tasks (EF and Triangles search tests). Accuracy (ACC) and response times (RTs) were analyzed with generalized mixed models. We investigated differences in baseline performance, clinical-demographic and lesion factors between tDCS responders and non-responders, based on post-tDCS behavioral improvements. Lastly, we conducted exploratory analyses to compare left and right brain-damaged participants. RTs improved after active ipsilesional occipital and parietal tDCS in the visual search tasks, while no changes in ACC were detected. Responders to ipsilesional occipital tDCS (Triangle task) had shorter disease duration and smaller lesions of the parietal cortex and the superior longitudinal fasciculus. On the other end, on the EF test, those participants with larger damage of the temporo-parietal cortex or the fronto-occipital white matter tracts showed a larger benefit from contralesional parietal tDCS. Overall, the visual search RTs improvements were larger in participants with right-sided hemispheric lesions. The present result shows the facilitatory effects of occipital and parietal tDCS combined with compensatory multisensory training on visual field exploration in HVFDs, suggesting a potential for the development of new neuromodulation treatments to improve visual scanning behavior in brain-injured patients.

Post Stroke, Is Perimetry Necessary? A Case Report

Abstract
 Introduction : Stroke are generally associated with peripheral visual field loss. Three out of four stroke patients report some form of disability, one of which is visual impairment. Approximately 16% of these patients have a homonymous visual field defect poststroke. These vision problems can lead to difficulty carrying out a lot of daily tasks and activities, such as driving. This report tries to define the diagnostic flow to determine the exact type and lesion.
 Case Illustration : Male, 61 years old, came to Universitas Sumatera Utara Hospital with visual field loss in both eyes. Two months ago, he was diagnosed with ischemic stroke and treated with Aspirin 80 mg, with no limbs disability right now. He also had hypertension and treated with Amlodipine 10 mg. VOD: 6/60 with BCVA S-2.00 6/7,5, VOS: 6/60 with BCVA S-2.00 6/7.5. With confrontation test and perimetry, defect was found in medial visual field OD and lateral visual field OS. Hess screen and Amsler Grid was normal. Head CT-Scan was performed with multiple infarcts, mainly in right occipital lobe. The patient was diagnosed with Incomplete Hemianopia, Left Congruous Homonymous Hemianopia with Macular Sparing, and treated with Citicholine 1000 mg once daily.
 Discussion
 Conclusion : In stroke patients with homonymous visual field loss, visual field testing with detailed evaluation of visual field defect can determine the lesion location, and neuro-radiological imaging was necessary to assess visual pathway. It’s important for educate the patients, diagnostic and prevent the stroke recurrent.

FunctionaL Assessment Scale of Hemianopia (FLASH): A New Multidisciplinary Tool to Assess Hemianopia in Patients with Severe Acquired Brain Injury.

Severe acquired brain injury (sABI) encompasses a range of neurological impairments. Visual dysfunction, particularly homonymous visual field defects (HVFDs) and homonymous hemianopia (HH), commonly afflicts sABI survivors, affecting their cognitive and motor rehabilitation. This study presents the FunctionaL Assessment Scale of Hemianopia (FLASH), developed to analyze the most common postural behaviors exhibited by sABI patients with hemianopia during activities of daily living. A comparison to traditional static automated perimetry for diagnosing visual field deficits (VFDs) to determine the sensitivity and specificity of the FLASH was used. Additionally, this study also aimed to assess its reliability. Fifty-six patients (25 F, 31 M, mean age 60.59 ± 14.53) with strokes in the sub-acute phase (<6 months from the onset) were assessed with both FLASH and a Humphrey Field Analyzer. After removing two items found to be less reliable than others, FLASH showed high sensitivity (81%) and specificity (77%) when compared to static automated perimetry. Inter-rater reliability was also high, with an intra-class correlation coefficient of 0.954, as well as the internal consistency computed by Cronbach's alpha, equal to 0.874. FLASH could offer a valuable and cost-effective screening tool for VFD in sABI patients during neurorehabilitation, with potential implications for healthcare cost reduction.

Volume and Visual Field Defects in Occipital Stroke: The NOR-OCCIP Study

Introduction. The majority of patients with occipital infarcts display homonymous visual field defects (VFD), with negative implications on activities of daily living and quality of life. To overcome the disability, better prognostic markers in the acute phase, as well as more targeted rehabilitation, would be useful. The aim of the current study was to present an overview of the topographic distribution of occipital infarcts and to investigate whether lesion volume can predict VFD at baseline and after six months. Materials and Methods. Multicenter, prospective study including patients with acute occipital infarcts (NOR-OCCIP project). All patients were examined by a neurologist in the acute phase, admitted to a stroke unit, and further assessed by an ophthalmologist within two weeks. Topographic and volumetric data from brain imaging in 72 patients were analyzed and computed by an experienced neuroradiologist. Results. A majority (81%) had occipital infarcts with involvement of the primary visual cortex, and VFD were detected on perimetry in 80% of the examined patients. Higher infarct volume led to more severe VFD at baseline ( p = 0.019 ); this was more evident if the infarct was located on the right side ( p = 0.001 ). The odds for VFD improvement after six months were higher the larger the infarcts were ( p = 0.020 ). There was a statistically significant association between volume of infarcts and atrial fibrillation ( p = 0.016 ), previous myocardial infarction ( p = 0.023 ), and modified Rankin Scale at three months ( p = 0.007 ). Conclusion. Higher infarct volumes led to more severe VFD at baseline. More than half of the patients (54%) experienced improvement of their VFD at six months; a higher grade of improvement was seen in patients with larger occipital infarcts. Large infarcts were more common in patients with cardiovascular disease, strengthening the argument for secondary prevention.

The effects of rehabilitative interventions on reading disorders caused by homonymous visual field defects: a meta-analysis focusing on improvement in reading speed.

Reading disorders caused by homonymous visual field defects (HVFDs) have a significant impact on a patient's quality of life. However, no review has been conducted to evaluate the available evidence on the effects of rehabilitative interventions on reading disorders caused by HVFDs. Thus, the aim of this study was to systematically evaluate the effects of rehabilitative interventions on reading disorders caused by HVFDs. We searched the MEDLINE/PubMed, Cochrane Library, ClinicalTrials.gov, CINAHL, and ScienceDirect databases for relevant articles. Relevant search terms were used to identify reports of randomized controlled trials or randomized crossover trials published between January 1990 and December 2021. Only studies that included reading-speed-related outcomes were analyzed. Risk of bias was assessed using the PEDro scale. Meta-analysis was conducted using a random-effects model, and standardized mean differences (SMD) and 95% confidence intervals (CIs) were calculated. Heterogeneity was assessed using the Ι2 statistic. Nine studies were included in the meta-analysis. The results showed that rehabilitative interventions significantly improved reading disorders caused by HVFDs (SMD = 0.30; 95% CI 0.08-0.51; P < 0.01; Ι2 = 0.0%). Subgroup analysis showed that reading training significantly improved reading disorders (SMD = 0.35; 95% CI 0.05-0.66; P = 0.02; Ι2 = 0.0%). Reading disorders caused by HVFDs can be improved through rehabilitation. In addition, reading training for the improvement of eye movement and fixation to compensate for foveal and parafoveal visual field defects may improve reading speed.

Effects of Stimulus Luminance, Stimulus Color and Intra-Stimulus Color Contrast on Visual Field Mapping in Neurologically Impaired Adults Using Flicker Pupil Perimetry.

We improve pupillary responses and diagnostic performance of flicker pupil perimetry through alterations in global and local color contrast and luminance contrast in adult patients suffering from visual field defects due to cerebral visual impairment (CVI). Two experiments were conducted on patients with CVI (Experiment 1: 19 subjects, age M and SD 57.9 ± 14.0; Experiment 2: 16 subjects, age M and SD 57.3 ± 14.7) suffering from absolute homonymous visual field (VF) defects. We altered global color contrast (stimuli consisted of white, yellow, cyan and yellow-equiluminant-to-cyan colored wedges) in Experiment 1, and we manipulated luminance and local color contrast with bright and dark yellow and multicolor wedges in a 2-by-2 design in Experiment 2. Stimuli consecutively flickered across 44 stimulus locations within the inner 60 degrees of the VF and were offset to a contrasting (opponency colored) dark background. Pupil perimetry results were compared to standard automated perimetry (SAP) to assess diagnostic accuracy. A bright stimulus with global color contrast using yellow (p=0.009) or white (p=0.006) evoked strongest pupillary responses as opposed to stimuli containing local color contrast and lower brightness. Diagnostic accuracy, however, was similar across global color contrast conditions in Experiment 1 (p=0.27) and decreased when local color contrast and less luminance contrast was introduced in Experiment 2 (p=0.02). The bright yellow condition resulted in highest performance (AUC M =0.85±0.10, Mdn=0.85). Pupillary responses and pupil perimetry's diagnostic accuracy both benefit from high luminance contrast and global but not local color contrast.

Quantification of retinal ganglion cell loss in patients with homonymous visual field defect due to stroke.

To quantify the degree of ganglion cell degeneration through spectral domain optical coherence tomography (SD-OCT) in adult patients with post-stroke homonymous visual field defect. Fifty patients with acquired visual field defect due to stroke (mean age = 61years) and thirty healthy controls (mean age = 58years) were included. Mean deviation (MD) and pattern standard deviation (PSD), average peripapillary retinal nerve fibre layer thickness (pRNLF-AVG), average ganglion cell complex thickness (GCC-AVG), global loss volume (GLV) and focal loss volume (FLV) were measured. Patients were divided according to the damaged vascular territories (occipital vs. parieto-occipital) and stroke type (ischaemic vs. haemorrhagic). Group analysis was conducted with ANOVA and multiple regressions. pRNFL-AVG was significantly decreased among patients with lesions in parieto-occipital territories compared to controls and to patients with lesions in occipital territories (p = .04), with no differences with respect to stroke type. GCC-AVG, GLV and FLV differed in stroke patients and controls, regardless of stroke type and involved vascular territories. Age and elapsed time from stroke had a significant effect on pRNFL-AVG and GCC-AVG (p < .01), but not on MD and PSD. Reduction of SD-OCT parameters occurs following both ischaemic and haemorrhagic occipital stroke, but it is larger when the injury extends to parietal territories and increases as time since stroke increases. The size of visual field defect is unrelated to SD-OCT measurements. Macular GCC thinning appeared to be more sensitive than pRNFL in detecting retrograde retinal ganglion cell degeneration and its retinotopic pattern in stroke.

Transsynaptic Ganglion Cell Degeneration in Adult Patients After Occipital Lobe Stroke.

Loss of retinal ganglion cells after occipital lobe damage is known to occur through transsynaptic retrograde degeneration in congenital lesions; however, studies of this phenomenon in acquired pathology, such as strokes affecting postgenicular visual pathway, are scant. We studied a cohort of adult patients with known onset of occipital lobe stroke to look for the presence, rate, and timing of macular ganglion cell loss on optical coherence tomography. Retrospective review of patients seen in tertiary neuro-ophthalmology practice with homonymous hemianopia secondary to occipital lobe stroke of known onset. Optical coherence tomography of the macular ganglion cell complex (GCC) was performed, and hemifields corresponding to the side of the visual field (VF) defect were compared with the control retinal hemifield. Fifteen patients with homonymous VF defects were included in the study, and 8 of these (53.3%) demonstrated GCC hemifield thickness of less than 90% on the side corresponding to VF loss including 2/9 (22%) patients who had a stroke less than 2.5 years ago and 6/6 (100%) patients who had a stroke longer than 2.5 years ago. The amount of hemifield atrophy correlated to the logarithm of time since stroke onset ( P =0.030) but not age ( P = 0.95) or mean deviation on VF ( P = 0.19). Three patients with longitudinal data showed GCC thinning rates of 1.99, 5.13, and 5.68 µm per year. Transsynaptic retrograde degeneration occurs after occipital lobe stroke as early as 5.5 months after injury and was observed in all patients 2.5 years after stroke.

How to test blindsight without light scatter artefacts?

light scatter artefacts are a methodological problem in testing residual visual capacities (RVCs), for instance blindsight, in patients with homonymous visual field defects (HVFDs). The term light scatter artefact describes the phenomenon that light from targets directed towards the HVFD can stray into the sighted visual field. This might enable an observer to respond correctly to information directed at her blind field despite the fact that she is unable to process that information in the blind field itself. In this manuscript, we present a review of the relevance of light scatter in visual neuroscience, discuss factors that influence the impact of light scatter and evaluate means to test for light scatter artefacts. Furthermore, we present findings from an empirical study that was aimed at developing tests for RVCs that are free of light scatter artefacts. Previous studies on light scatter only used small sample sizes and equipment that is no longer in use. Hence, their results cannot be generalized to future experiments making it necessary to run laborious light scatter tests for every new study on RVCs. To avoid this, we hereby start a pool of stimuli and paradigms which demonstrably do not elicit light scatter artefacts. To this end, we investigated 21 healthy young participants in three frequently used RVC-paradigms: (1) temporal 2AFC task, (2) movement direction discrimination, and (3) redundant target paradigm. For each paradigm, we applied the blind-spot method. But first, we had to establish that our testing paradigm was sufficiently sensitive to detect light scatter artefacts. For this, we used conditions that are known to produce strong light scatter and a paradigm that is very sensitive to such effects. Specifically, we presented white targets on a black background in a dark room. The stimuli were presented to observers’ blind spot. To check for light scatter artefacts, we used a target-detection task in a temporal 2AFC format. We obtained clear light scatter artefacts. Participants produced reliably above-chance detection performance under these conditions. The other two luminance conditions, measured in an illuminated room, did not produce light scatter artefacts. Accuracy in the temporal 2AFC task was at chance level for white targets on a grey background at the blind-spot position. Additionally, black targets on a grey background avoided light scatter artefacts in all three RVC-paradigms. In future, researchers can apply these stimulus and illumination conditions when using one of the three above paradigms in their studies. Using these conditions, they will be able to avoid light scatter artefacts without having to perform their own blind-spot tests.

Resting-state Functional Connectivity After Occipital Stroke

Background Resting-state functional magnetic resonance imaging (rsfMRI) reflects spontaneous activation of cortical networks. After stroke, these networks reorganize, both due to structural lesion and reorganization of functional connectivity (FC). Objective We studied FC in chronic phase occipital stroke patients with homonymous visual field defects before and after repetitive transorbital alternating current stimulation (rtACS). Methods This spin-off study, embedded in the randomized, sham-controlled REVIS trial, comprised 16 chronic occipital stroke patients with visual field defect and 12 healthy control subjects. The patients underwent rsfMRI at baseline, after two weeks of rtACS or sham treatment, and after two months of treatment-free follow-up, whereas the control subjects were measured once. We used a multivariate regression connectivity model to determine mutual prediction accuracy between 74 cortical regions of interest. Additionally, the model parameters were included into a graph to analyze average path length, centrality eigenvector, centrality degree, and clustering of the network. The patients and controls at baseline and the two treatment groups were compared with multilevel modeling. Results Before treatment, the patients and controls had similar whole-network prediction accuracy and network parameters, whereas centrality eigenvector differed in perilesional regions, indicating local modification in connectivity. In line with behavioral results, neither prediction accuracy nor any network parameter changed systematically as a result of rtACS rehabilitation compared to sham. Conclusions Whole-network FC showed no difference between occipital stroke patients and healthy population, congruent with the peripheral location of the visual network in relation to the high-density cortical core. rtACS treatment in the given setting did not affect FC.

Homonymous visual field defect and retinal thinning after occipital stroke

IntroductionStroke is the most common cause of homonymous visual field defects (VFD). About half of the stroke patients recover from VFD. However, relationship between VFD and retinal changes remains elusive.PurposeTo investigate the association between occurrence of VFD, changes of macular ganglion cell and inner plexiform layer (GCIPL) and its axon retinal nerve fiber layer (RNFL) detected with optical coherence tomography (OCT).Patients and methodsThe study consists of retrospective review of medical records and follow‐up examinations. Patients with acute occipital stroke were registered. VFD was identified with confrontation and/or perimetry tests at the onset. At follow‐up, the patients were examined with visual field tests and OCT measurements.ResultsThirty‐six patients met the inclusion criteria. At onset, 26 patients (72%) had VFD. At follow‐up >1 year after stroke, 13 patients (36%) had remaining VFD: 5 had homonymous hemianopia, 5 had homonymous quadrantanopia, and 3 had homonymous scotomas. Average thickness of GCIPL and RNFL were significantly reduced in each eye in patients with VFD compared to non‐VFD (NVFD) (p < .01 for all comparisons). Thickness of superior and inferior RNFL quadrants was significantly reduced in VFD compared to NVFD (p < .01 for both). Among these 13 patients, 4 had characteristic homonymous quadrant‐GCIPL thinning, 2 had characteristic homonymous hemi‐GCIPL thinning, and 7 had diffuse GCIPL thinning.ConclusionGCIPL and RNFL thinning were observed in the patients with VFD. GCIPL thinning appears in two forms: atypical diffuse thinning, or homonymous hemi‐GCIPL thinning. Examining GCIPL and RNFL provides easy and reliable objective measures and is therefore proposed to be of predictive value on visual function.

Prognostic Factors for Long-Term Recovery of Homonymous Visual Field Defects After Posterior Circulation Ischemic Stroke

ObjectivesIschemic stroke (IS) is the main cause of homonymous visual field defects (HVFDs) in adults. Some reports suggest recovery even in late-phase strokes, but data is sparse. This study examines the frequency of long-term recovery from HVFDs in patients with posterior circulation infarction (POCI) and evaluates whether demographic or clinical characteristics are prognostic factors of perimetric recovery. Materials and MethodsOur study included patients with HVFDS due to POCI who had undergone 2 or more kinetic perimetric evaluations at least 6 months after the index IS. Clinical and imaging data were systematically reviewed and we performed univariate and multivariate logistic regression analyses to determine whether demographic, stroke etiology (TOAST classification), and initial perimetric patterns were prognostic factors of visual recovery occurring 6 months and beyond from POCI. ResultsOne hundred one patients with POCI were included. Median subject age was 60 years and 54.4% were female. After a median perimetric follow-up time of 13.5 months, spontaneous visual improvement was observed in 15.8% of patients. Prognostic factors for visual improvement were age < 50 years (OR 4.6; P = 0.093), POCI associated with hypercoagulable states (OR 12.3; P = 0.048), and vertebral artery dissection (OR 12.6; P = 0.048), while the presence of complete homonymous hemianopia was a negative predictor of recovery (OR 0.2; P = 0.048). ConclusionPartial visual recovery in HVFDs is observed even 6 months and beyond POCI. Age < 50 years and stroke etiology were predictors of recovery.

Driving with hemianopia VIII: Effects of a vibro-tactile assistance system on safety and gaze behavior in pedestrian crossing situations.

People with homonymous visual field defects (HVFDs), the loss of vision in the same half of the visual field in both eyes, are permitted to drive in some jurisdictions. However, the HVFD may cause difficulties in detecting hazards approaching on the side of the field loss (the blind side). An advanced driver assistance system (ADAS) could assist with hazard detection, but little research has been conducted to evaluate the potential benefits of an ADAS for visually impaired drivers. We developed a prototype vibro-tactile assistance system for drivers with HVFDs and conducted a proof-of-concept driving simulation study to evaluate the system. Given that pedestrian accidents are the second most frequent cause of death in road traffic and most of those accidents occur in urban scenarios, we evaluated the potential of the assistance system to improve responses to pedestrian hazards in a city environment. Sixteen participants, of which eight had HVFDs and eight had normal vision, took part. Our analyses evaluated the effects of the driver assistance system, crossing direction and pedestrian behavior on the safety of pedestrian events and the participant's gaze behavior at each of the 256 crossing situations. Generalized linear mixed effects models were used to assess binomial outcome variables. Despite the limited sample size, the results suggest that the vibro-tactile directional warnings were effective in directing the drivers' gaze so that they were looking in the necessary direction before a potential hazard occurred. More time was spent fixating pedestrians on the blind side when the ADAS was engaged and as a result, the safety of street crossings from the blind side improved. The effect of the ADAS was greater on responses to pedestrians from the blind than the seeing side. With an activated ADAS, crossings from the participants' blind sides were as safe as from their seeing sides, and as safe as the crossings when normally-sighted participants were driving. The results suggest that the vibro-tactile ADAS is a promising approach to improve the safety of drivers with HVFD and surrounding traffic.

Functional MRI of visual cortex predicts training-induced recovery in stroke patients with homonymous visual field defects

Post-chiasmatic damage to the visual system leads to homonymous visual field defects (HVDs), which can severely interfere with daily life activities. Visual Restitution Training (VRT) can recover parts of the affected visual field in patients with chronic HVDs, but training outcome is variable. An untested hypothesis suggests that training potential may be largest in regions with ‘neural reserve’, where cortical responses to visual stimulation do not lead to visual awareness as assessed by Humphrey perimetry—a standard behavioural visual field test. Here, we tested this hypothesis in a sample of twenty-seven hemianopic stroke patients, who participated in an assiduous 80-hour VRT program. For each patient, we collected Humphrey perimetry and wide-field fMRI-based retinotopic mapping data prior to training. In addition, we used Goal Attainment Scaling to assess whether personal activities in daily living improved. After training, we assessed with a second Humphrey perimetry measurement whether the visual field was improved and evaluated which personal goals were attained. Confirming the hypothesis, we found significantly larger improvements of visual sensitivity at field locations with neural reserve. These visual field improvements implicated both regions in primary visual cortex and higher order visual areas. In addition, improvement in daily life activities correlated with the extent of visual field enlargement. Our findings are an important step toward understanding the mechanisms of visual restitution as well as predicting training efficacy in stroke patients with chronic hemianopia.

Occipital Lobe Abscess Causing Homonymous Hemianopsia After a Dental Procedure

Background: A homonymous hemianopsia visual field defect is defined as vision loss on the same side of the vertical midline in both eyes. Although the vast majority are caused by an ischemic stroke, other neurologic etiologies must be considered and ruled out. This case highlights the importance of a rapid and thorough investigation of a patient’s symptoms using both clinical examination and imaging to reduce the risk of permanent complications and potential fatality. Case Report: A 67-year-old Caucasian male presented to the eye clinic with sudden onset reduced peripheral vision to his right side in both eyes. Entering visual acuities were 20/40 OD and 20/60 OS. Humphrey visual field (HVF) testing confirmed a complete right homonymous hemianopsia. Magnetic resonance imaging (MRI) revealed a large, left occipital lobe intracranial mass. Neurosurgical intervention was necessary to confirm the diagnosis of a brain abscess, thought to be related to a prior dental procedure with tooth extraction. Conclusion: A brain abscess is a focal area of necrosis within the brain parenchyma that typically results from an infectious process. Though rare, the condition has potentially devastating neurologic complications which can be mitigated with early detection and treatment. In this case, the abscess caused a right homonymous hemianopsia field defect, which prompted his urgent request for an appointment with the eye clinic.

Rehabilitation of cortically induced visual field loss.

Homonymous visual field defects are a common sequela of stroke, and are assumed to be permanent within a few weeks of the event. Because consensus about the efficacy of rehabilitation is lacking, visual therapy is rarely prescribed. Here, we review current rehabilitation options and strategies in the translational pipeline that could change these perspectives. The mainstays of available therapy for homonymous visual defects are compensation training and substitution, which allow patients to better use their spared vision. However, early clinical studies suggest that vision can partially recover following intensive training inside the blind field. Research into the relative efficacy of different restorative approaches continues, providing insights into neurophysiologic substrates of recovery and its limitations. This, in turn, has led to new work examining the possible benefits of earlier intervention, advanced training procedures, noninvasive brain stimulation, and pharmacological adjuvants, all of which remain to be vetted through properly powered, randomized, clinical trials. Research has uncovered substantial visual plasticity after occipital strokes, suggesting that rehabilitative strategies for this condition should be more aggressive. For maximal benefit, poststroke vision-restorative interventions should begin early, and in parallel with strategies that optimize everyday use of an expanding field of view.

Ophthalmic manifestations of myelin oligodendrocyte glycoprotein-IgG-associated disorder other than optic neuritis: a systematic review

Background/AimsOptic neuritis (ON) is the primary ophthalmic manifestation of myelin oligodendrocyte glycoprotein-IgG-associated disorder (MOGAD), but numerous reports have expanded the visual manifestations of this condition. The goal of this study...

Homonymous visual field defects in patients with multiple sclerosis: results of computerised perimetry and optical coherence tomography.

Visual dysfunction is frequent in multiple sclerosis, usually resulting from retrobulbar optic neuritis or papillitis. Less frequently, demyelinating lesions can affect the retrochiasmal pathways. There are few reports of homonymous visual field defects (HVFD) in multiple sclerosis and little is known about their evolution. The purpose of this study was to better define both the clinical profile and the evolution of HVFD in patients with multiple sclerosis. We performed a retrospective study of all multiple sclerosis patients who presented HVFD and were examined by automated static perimetry. A subset of patients benefited from macular assessment with optical coherence tomography (OCT). We also reviewed the worldwide literature on the subject. Twenty patients were retrieved from the neuro-ophthalmology database of the H&ocirc;pital Ophtalmique Jules-Gonin. There were 11 women and 9 men, and their average age was 35 &plusmn; 11 years. The relapsing-remitting form of multiple sclerosis was most common (18/20; 90%), the primary progressive form (1/20; 5%) and the secondary progressive form (1/20; 5%) were rare. HVFD were the presenting symptom of multiple sclerosis in seven patients (35%). The recovery was complete in 12/20 patients (60%), and the median time to recovery was 10 weeks (2-13 weeks). An incomplete recovery was found in 5/20 subjects (25%) and no recovery occurred in 3/20 subjects (15%). Magnetic resonance imaging disclosed a definite lesion explaining the HVFD in 7/11 patients: five within the optic radiations (71.4%), one within the optic tract (14.3%) and one within the lateral geniculate nucleus (14.3%). Our results were comparable to those compiled from our literature search (29 publications, totalling 70 cases). A recurrent episode of HVFD occurred in three patients (15%). OCT was performed in 10/20 patients. Retinal ganglion cell layer thickness was assessed and revealed a homonymous thinning in three patients, diffuse unilateral or bilateral thinning (resulting from previous episodes of optic neuritis) in six patients, and normal retinal ganglion cell layer thickness in one patient. HVFD in multiple sclerosis are found mostly in young patients with relapsing-remitting multiple sclerosis, which is consistent with the epidemiology of multiple sclerosis. HVFD can be the first manifestation of multiple sclerosis and have a relatively good prognosis. Like optic neuritis, HVFD can recur. The incidence of HVFD in multiple sclerosis is unknown, as it is probably underdiagnosed. Systematic automated static perimetry and OCT could help to determine the true incidence of HVFD in multiple sclerosis. &nbsp.