Rapid compensation of visual search strategy in patients with chronic visual field defects

Meeting the need for post-stroke vision care in Australia: a scoping narrative review of current practice

PURPOSE

Determine current vision care pathways and practices for stroke survivors in Australia and internationally, focusing on identifying reoccurring gaps in these pathways and unmet care needs.

METHOD

A scoping narrative review was conducted to identify literature related to post-stroke vision care practices and perspectives of patients and health professionals.

RESULTS

A total of 16193 articles were retrieved and 28 deemed eligible for inclusion. Six were Australian, 14 from the UK, four from the USA, and four from within Europe. Post-stroke vision care is largely unstandardized, with substantial inconsistency in the use of vision care protocols, who executes them and at what point in post-stroke care they are utilised. Health professionals and stroke survivors expressed that unmet care needs were primarily a result of lack of education and awareness regarding post-stroke eye problems. Other gaps in care pathways related to the timing of vision assessment, provision of ongoing support, and the integration of eye-care specialists into the stroke team.

CONCLUSION

Further research is needed into current Australian post-stroke vision care to accurately assess whether the needs of stroke survivors are being met. Available evidence indicates that in Australia, there is a requirement for well-defined protocols for vision screening, education, management, and referral of stroke survivors.

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.

Fractal Phototherapy in Maximizing Retina and Brain Plasticity

The neuroplasticity potential is reduced with aging and impairs during neurodegenerative diseases and brain and visual system injuries. This limits the brain's capacity to repair the structure and dynamics of its activity after lesions. Maximization of neuroplasticity is necessary to provide the maximal CNS response to therapeutic intervention and adaptive reorganization of neuronal networks in patients with degenerative pathology and traumatic injury to restore the functional activity of the brain and retina.Considering the fractal geometry and dynamics of the healthy brain and the loss of fractality in neurodegenerative pathology, we suggest that the application of self-similar visual signals with a fractal temporal structure in the stimulation therapy can reactivate the adaptive neuroplasticity and enhance the effectiveness of neurorehabilitation. This proposition was tested in the recent studies. Patients with glaucoma had a statistically significant positive effect of fractal photic therapy on light sensitivity and the perimetric MD index, which shows that methods of fractal stimulation can be a novel nonpharmacological approach to neuroprotective therapy and neurorehabilitation. In healthy rabbits, it was demonstrated that a long-term course of photostimulation with fractal signals does not harm the electroretinogram (ERG) and retina structure. Rabbits with modeled retinal atrophy showed better dynamics of the ERG restoration during daily stimulation therapy for a week in comparison with the controls. Positive changes in the retinal function can indirectly suggest the activation of its adaptive plasticity and the high potential of stimulation therapy with fractal visual stimuli in a nonpharmacological neurorehabilitation, which requires further study.

Tumor location-based classification of surgery-related language impairments in patients with glioma

INTRODUCTION

Many patients with glioma experience surgery-related language impairment. This study developed a classification system to predict postoperative language prognosis.

METHODS

Sixty-eight patients were retrospectively reviewed. Based on their location, tumors were subtyped as follows: (I) inferior frontal lobe or precentral gyrus; (II) posterior central gyrus or supramarginal gyrus (above the lateral fissure level); (III) posterior region of the superior or middle temporal gyri or supramarginal gyrus (below the lateral fissure level); and (IV) insular lobe. The distance from the tumor to the superior longitudinal fasciculus/arcuate fasciculus was calculated. The recovery of language function was assessed using the Western Aphasia Battery before surgery, and a comprehensive language test was conducted on the day of surgery; 3, 7, and 14 days after surgery. Our follow-up information of was the comprehensive language test from telephone interviews in 3 months after surgery.

RESULTS

Thirty-three patients experienced transient language impairment within 1 week of surgery. Fourteen patients had permanent language impairment. Type II tumors, shorter distance from the tumor to the posterior superior longitudinal fasciculus/arcuate fasciculus, and isocitrate dehydrogenase mutations were risk factors for surgery-related language impairment. Regarding the presence or absence of permanent surgery-related language impairments, the cut-off distance between the tumor and posterior superior longitudinal fasciculus/arcuate fasciculus was 2.75 mm.

CONCLUSIONS

According to our classification, patients with type II tumors had the worst language prognosis and longest recovery time. Our classification, based on tumor location, can reliably predict postoperative language status and may be used to guide tumor resection.

The feasibility and effects of eye movement training for visual field loss after stroke: a mixed methods study

Introduction

Visual field loss affects around 20% of stroke survivors, reducing quality of life. Eye movement training is a promising rehabilitation method, and several different interventions are used by occupational therapists. This study aimed to explore the feasibility and effects of four eye movement training interventions for stroke survivors with visual field loss.

Method

A mixed methods study – quantitative n-of-1 with qualitative interviews. The participants were 11 home-dwelling stroke survivors with visual field loss. The interventions used were MyHappyNeuron, NVT, Rainbow Readers and VISIOcoach, delivered in a randomised order. Visual search, reading speed, activities of daily living and quality of life were assessed three times before intervention use, then immediately after each intervention; these were analysed visually. A final semi-structured interview was then analysed using framework methods.

Results

Evidence of effect was divergent. Quantitatively there was no measured effect, but qualitatively participants reported benefits in visual skills, daily life skills and emotions, which varied by intervention. Median training time was 3–4 hours (range 0.5–6.5) for NVT, Rainbow Readers and MyHappyNeuron, and 9.5 hours (range 2.3–16.8) for VISIOcoach.

Conclusion

Eye movement training interventions were feasible for stroke survivors at home. Qualitative evidence suggests that variations in the eye movements trained and delivery modality underlie variations in perceived effect.

Rehabilitation of visual disorders

While there is a long history of rehabilitation for motor deficits following cerebral lesions, less is known about our ability to improve visual deficits. Vision therapy, prisms, occluders, and filters have been advocated for patients with mild traumatic brain injury, on the premise that some of their symptoms may reflect abnormal visual or ocular motor function, but the evidence for their efficacy is modest. For hemianopia, attempts to restore vision have had unimpressive results, though it appears possible to generate blindsight through training. Strategic approaches that train more efficient use of visual search in hemianopia have shown consistent benefit in visual function, while prism aids may help some patients. There are many varieties of alexia. Strategic adaptation of saccades can improve hemianopic alexia, but there has been less work and mixed results for pure alexia, neglect dyslexia, attentional dyslexia, and the central dyslexias. A number of approaches have been tried in prosopagnosia, with recent studies of small groups suggesting that face perception of prosopagnosic subjects can be enhanced through perceptual learning.

Rehabilitation of cortically induced visual field loss

PURPOSE OF REVIEW

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.

RECENT FINDINGS

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.

SUMMARY

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.

Aging and the rehabilitation of homonymous hemianopia: The efficacy of compensatory eye-movement training techniques and a five-year follow up

The specificity and effectiveness of eye-movement training to remedy impaired visual exploration and reading with particular consideration of age and co-morbidity was tested in a group of 97 patients with unilateral homonymous hemianopia using a single subject /n-of-1 design. Two groups received either scanning training followed by reading training, or vice versa. The third group acted as a control group and received non-specific detailed advice, followed by training of scanning and reading. Scanning and reading performance was assessed before and after the waiting period, before and after scanning and reading training, and at short-term (11 weeks on average) and long-term follow-up (5 years on average). Improvements after training were practice-dependent and task-specific. Scanning performance improved by ∼40%, reading by ∼45%, and was paralleled by a reduction of subjective complaints. The advice (=control) condition was without effect. All improvements occurred selectively in the training period, not in treatment-free intervals, and persisted in the short- and long-term follow-up over several years. Age had only a minor, although significant effect on improvement in reading after training; co-morbidity had no significant impact on the outcome of training. In conclusion, visual impairments associated with homonymous hemianopia can be successfully and durably reduced by systematic and specific training of compensatory eye-movement strategies. The improvements in compensation strategies were independent of subjects' age and of co-morbidity.

Behavioural performance improvement in visuomotor learning correlates with functional and microstructural brain changes

A better understanding of practice-induced functional and structural changes in our brains can help us design more effective learning environments that provide better outcomes. Although there is growing evidence from human neuroimaging that experience-dependent brain plasticity is expressed in measurable brain changes that are correlated with behavioural performance, the relationship between behavioural performance and structural or functional brain changes, and particularly the time course of these changes, is not well characterised. To understand the link between neuroplastic changes and behavioural performance, 15 healthy participants in this study followed a systematic eye movement training programme for 30 min daily at home, 5 days a week and for 6 consecutive weeks. Behavioural performance statistics and eye tracking data were captured throughout the training period to evaluate learning outcomes. Imaging data (DTI and fMRI) were collected at baseline, after two and six weeks of continuous training, and four weeks after training ended. Participants showed significant improvements in behavioural performance (faster task completion time, lower fixation number and fixation duration). Spatially overlapping reductions in microstructural diffusivity measures (MD, AD and RD) and functional activation increases (BOLD signal) were observed in two main areas: extrastriate visual cortex (V3d) and the frontal part of the cerebellum/Fastigial Oculomotor Region (FOR), which are both involved in visual processing. An increase of functional activity was also recorded in the right frontal eye field. Behavioural, structural and functional changes were correlated. Microstructural change is a better predictor for long-term behavioural change than functional activation is, whereas the latter is superior in predicting instantaneous performance. Structural and functional measures at week 2 of the training programme also predict performance at week 6 and 10, which suggests that imaging data at an early stage of training may be useful in optimising practice environments or rehabilitative training programmes.

The clinical effectiveness of Eye-Search therapy for patients with hemianopia, neglect or hemianopia and neglect

We investigated the clinical effectiveness of Eye-Search, a web-based therapy app designed to improve visual search times, in a large group of patients with either hemianopia, neglect or both hemianopia and neglect. A prospective, interventional cohort design was used. For the main, impairment-based outcome measure (average visual search time), the within-subject control was affected vs. unaffected side. Four hundred and twenty-six participants who fitted the inclusion criteria completed all 4 time points (1200 therapy trials). We found a significant three-way interaction between therapy, side and group. Eye-Search therapy improved search times to the affected visual field of patients with either hemianopia alone or neglect and hemianopia, but not those with neglect alone. Effect sizes were moderate to large and consistent with previous studies. We found a similar significant interaction between therapy and group for the patient-reported outcome measure "finding things" that most closely matched the impairment-based outcome (visual search). Eye-Search therapy improves both impairment-based and patient-reported outcome measures related to visual search in patients with hemianopia alone or hemianopia and neglect.

Occupational Therapy Interventions to Improve Reading Performance of Older Adults With Low Vision: A Systematic Review

IMPORTANCE

Low vision affects many older adults and is expected to significantly increase over the next several decades. It has a significant impact on all aspects of daily life, including the reading required for participation in occupations.

OBJECTIVE

To determine the effectiveness of interventions within the scope of occupational therapy to improve reading required for the performance of occupations by older adults with low vision.

DATA SOURCES

We conducted a systematic review of literature published in the Cochrane Database of Systematic Reviews, MEDLINE, PsycINFO, CINAHL, and OTseeker databases from 2010 through 2016. The references of retrieved articles were also hand searched.

STUDY SELECTION AND DATA COLLECTION

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to abstract and assess data quality and validity. This review followed the established methodology of the American Occupational Therapy Association Evidence-Based Practice Project.

FINDINGS

Sixteen articles met the inclusion criteria and were categorized into three themes: (1) technology, (2) visual skills training, and (3) multicomponent interventions. Moderate evidence supports stand-based electronic magnification and eccentric viewing training to improve reading outcomes. Strong evidence supports multicomponent interventions.

CONCLUSIONS AND RELEVANCE

Occupational therapy practitioners working with older adults with low vision are strongly encouraged to integrate stand-based electronic magnification, eccentric viewing training, and comprehensive low vision services into routine care. Further research with larger sample sizes and functional reading outcome measures is needed.

WHAT THIS ARTICLE ADDS

This review provides additional support for the use of select occupational therapy interventions (stand-based electronic magnification, eccentric viewing training, and comprehensive low vision services) to support the reading required for occupational performance for older adults with low vision. The findings provide guidance to occupational therapy practitioners for selection and implementation of evidence-based interventions for reading.

Occupational Therapy Practice Guidelines for Older Adults With Low Vision

Importance: The aging of the population is generating increased demand for occupational therapy practitioners to address the occupational performance of those experiencing low vision.

Objective: This Practice Guideline, which is informed by systematic reviews on interventions for older adults with low vision, is meant to serve as a reference for occupational therapy practitioners to guide best practice in service delivery, improve quality of care, enhance consumer satisfaction, and justify occupational therapy services to external stakeholders. Interventions included in this guideline address performance of activities of daily living (ADLs) and instrumental activities of daily living (IADLs), reading, and leisure and social participation.

Method: We examined, synthesized, and integrated the results of three systematic reviews into recommendations for practice, education, and research.

Results: Thirty-eight articles were included in the systematic reviews, which served as the basis for clinical recommendations. A case study describes translation and application of the recommendations to clinical practice.

Conclusions and Recommendations: Strong evidence supports the role of occupational therapy for older adults with low vision. On the basis of the evidence, we recommend routine use of low vision rehabilitation for ADL and IADL impairments, multicomponent interventions to improve ADL and IADL performance and leisure and social participation, stand-based electronic magnification to enhance reading, and visual skills training to enhance reading for clients with a central field impairment. We recommend using client-centered problem-solving training to enhance ADL and IADL performance, reading, and leisure and social participation. Mainstream technology may be considered for use on a case-by-case basis to enhance reading performance. Finally, adapted tango may be considered for use on a case-by-case basis to enhance ADL and IADL performance and leisure and social participation.

What This Article Adds: This Practice Guideline provides a summary of the current evidence supporting occupational therapy intervention for older adults with low vision. It summarizes the emerging literature supporting the use of mainstream technology and provides additional support for the use of multicomponent intervention strategies.

Clinical provision of compensatory visual training after neurological injury: example of a multisite outpatient program

AIM

Treatment efficacy is established via controlled research trials, but treatment in real-world clinical environments is typically highly variable and may differ from research protocols by necessity. Here, we examined provision of visual retraining for adults after neurological injury at an outpatient rehabilitation program in Calgary, Canada.

METHODS

Retrospective chart audits extracted demographic data, assessment outcomes, and details related to provision of training.

RESULTS

Treatment was provided to individuals with both visual field and visual-perceptual impairments due to neurological injury (mostly stroke). Tools and techniques of visual retraining at this program are discussed, the common denominator being repetitive practice of compensatory visual behaviors. Across this multisite program, there was significant variability in the number of treatment sessions, 13.00 (±10.21) sessions for those with visual-perceptual impairments and 14.41 (±9.63) sessions for those with field loss. Descriptive statistics and confidence intervals suggest improved outcomes on some measures for those with visual field and visual perceptual impairments.

CONCLUSIONS

Our data suggest that visual retraining is feasible in this clinical outpatient setting. Implications for rehabilitation This program of visual retraining was provided to individuals with visual impairment (e.g., hemianopia) and visual perceptual impairment (e.g., unilateral spatial neglect) as a result of neurological injury. In this outpatient program, visual rehabilitation was feasible and appeared to improve outcomes among a heterogeneous clinical population. Fundamental characteristics of visual compensatory training at this program included repetitive practice of adaptive scanning behaviors across multiple contexts to promote automaticity and generalization of skills.

Adaptation to poststroke visual field loss: A systematic review

AIM

To provide a systematic overview of the factors that influence how a person adapts to visual field loss following stroke.

METHOD

A systematic review was undertaken (data search period 1861-2016) inclusive of systematic reviews, randomized controlled trials, controlled trials, cohort studies, observational studies, and case controlled studies. Studies including adult subjects with hemifield visual field loss, which occured as a direct consequence of stroke, were included. Search terms included a range of MESH terms as well as alternative terms relating to stroke, visual field loss, visual functions, visual perception, and adaptation. Articles were selected by two authors independently, and data were extracted by one author, being verified by the second. All included articles were assessed for risk of bias and quality using checklists appropriate to the study design.

RESULTS

Forty-seven articles (2,900 participants) were included in the overall review, categorized into two sections. Section one included seventeen studies where the reviewers were able to identify a factor they considered as likely to be important for the process of adaptation to poststroke visual field loss. Section two included thirty studies detailing interventions for visual field loss that the reviewers deemed likely to have an influence on the adaptation process. There were no studies identified which specifically investigated and summarized the factors that influence how a person adapts to visual field loss following stroke.

CONCLUSION

There is a substantial amount of evidence that patients can be supported to compensate and adapt to visual field loss following stroke using a range of strategies and methods. However, this systematic review highlights the fact that many unanswered questions in the area of adaptation to visual field loss remain. Further research is required on strategies and methods to improve adaptation to aid clinicians in supporting these patients along their rehabilitation journey.

Practice-related changes in eye movement strategy in healthy adults with simulated hemianopia

The impact of visual field deficits such as hemianopia can be mitigated by eye movements that position the visual image within the intact visual field. Effective eye movement strategies are not observed in all patients, however, and it is not known whether persistent deficits are due to injury or to pre-existing individual differences. Here we examined whether repeated exposure to a search task with rewards for good performance would lead to better eye movement strategies in healthy individuals. Participants were exposed to simulated hemianopia during a search task in five testing sessions over five consecutive days and received monetary payment for improvements in search times. With practice, most participants made saccades that went further into the blind field earlier in search, specifically under conditions where little information about the target location would be gained by inspecting the sighted field. These changes in search strategy were correlated with reduced search times. This strategy improvement also generalised to a novel task, with better performance in naming objects in a photograph under conditions of simulated hemianopia after practice with visual search compared to a control group. However, even after five days, eye movements in most participants remained far from optimal. The results demonstrate the benefits, and limitations, of practice and reward in the development of effective coping strategies for visual field deficits.

Rehabilitation of Visual Loss: Where We Are and Where We Need to Be

BACKGROUND

Spontaneous recovery of visual loss resulting from injury to the brain is variable. A variety of traditional rehabilitative strategies, including the use of prisms or compensatory saccadic eye movements, have been used successfully to improve visual function and quality-of-life for patients with homonymous hemianopia. More recently, repetitive visual stimulation of the blind area has been reported to be of benefit in expanding the field of vision.

EVIDENCE ACQUISITION

We performed a literature review with main focus on clinical studies spanning from 1963 to 2016, including 52 peer-reviewed articles, relevant cross-referenced citations, editorials, and reviews.

RESULTS

Repetitive visual stimulation is reported to expand the visual field, although the interpretation of results is confounded by a variety of methodological factors and conflicting outcomes from different research groups. Many studies used subjective assessments of vision and did not include a sufficient number of subjects or controls.

CONCLUSIONS

The available clinical evidence does not strongly support claims of visual restoration using repetitive visual stimulation beyond the time that spontaneous visual recovery might occur. This lack of firm supportive evidence does not preclude the potential of real benefit demonstrated in laboratories. Additional well-designed clinical studies with adequate controls and methods to record ocular fixation are needed.

Impact of Glaucoma and Dry Eye on Text-Based Searching

PURPOSE

We determine if visual field loss from glaucoma and/or measures of dry eye severity are associated with difficulty searching, as judged by slower search times on a text-based search task.

METHODS

Glaucoma patients with bilateral visual field (VF) loss, patients with clinically significant dry eye, and normally-sighted controls were enrolled from the Wilmer Eye Institute clinics. Subjects searched three Yellow Pages excerpts for a specific phone number, and search time was recorded.

RESULTS

A total of 50 glaucoma subjects, 40 dry eye subjects, and 45 controls completed study procedures. On average, glaucoma patients exhibited 57% longer search times compared to controls (95% confidence interval [CI], 26%-96%, P < 0.001), and longer search times were noted among subjects with greater VF loss (P < 0.001), worse contrast sensitivity (P < 0.001), and worse visual acuity (P = 0.026). Dry eye subjects demonstrated similar search times compared to controls, though worse Ocular Surface Disease Index (OSDI) vision-related subscores were associated with longer search times (P < 0.01). Search times showed no association with OSDI symptom subscores (P = 0.20) or objective measures of dry eye (P > 0.08 for Schirmer's testing without anesthesia, corneal fluorescein staining, and tear film breakup time).

CONCLUSIONS

Text-based visual search is slower for glaucoma patients with greater levels of VF loss and dry eye patients with greater self-reported visual difficulty, and these difficulties may contribute to decreased quality of life in these groups.

TRANSLATIONAL RELEVANCE

Visual search is impaired in glaucoma and dry eye groups compared to controls, highlighting the need for compensatory strategies and tools to assist individuals in overcoming their deficiencies.

The treatment methods for post-stroke visual impairment: A systematic review

AIM

To provide a systematic overview of interventions for stroke related visual impairments.

METHOD

A systematic review of the literature was conducted including randomized controlled trials, controlled trials, cohort studies, observational studies, systematic reviews, and retrospective medical note reviews. All languages were included and translation obtained. This review covers adult participants (aged 18 years or over) diagnosed with a visual impairment as a direct cause of a stroke. Studies which included mixed populations were included if over 50% of the participants had a diagnosis of stroke and were discussed separately. We searched scholarly online resources and hand searched articles and registers of published, unpublished, and ongoing trials. Search terms included a variety of MESH terms and alternatives in relation to stroke and visual conditions. Article selection was performed by two authors independently. Data were extracted by one author and verified by a second. The quality of the evidence and risk of bias was assessed using appropriate tools dependant on the type of article.

RESULTS

Forty-nine articles (4142 subjects) were included in the review, including an overview of four Cochrane systematic reviews. Interventions appraised included those for visual field loss, ocular motility deficits, reduced central vision, and visual perceptual deficits.

CONCLUSION

Further high quality randomized controlled trials are required to determine the effectiveness of interventions for treating post-stroke visual impairments. For interventions which are used in practice but do not yet have an evidence base in the literature, it is imperative that these treatments be addressed and evaluated in future studies.

Use of NeuroEyeCoach™ to Improve Eye Movement Efficacy in Patients with Homonymous Visual Field Loss

Visual field deficits are common in patients with damaged retinogeniculostriate pathways. The patient's eye movements are often affected leading to inefficient visual search. Systematic eye movement training also called compensatory therapy is needed to allow patients to develop effective coping strategies. There is a lack of evidence-based, clinical gold-standard registered medical device accessible to patients at home or in clinical settings and NeuroEyeCoach (NEC) is developed to address this need. In three experiments, we report on performance of patients on NEC compared to the data obtained previously on the earlier versions of the search task (n = 32); we assessed whether the self-administered computerised tasks can be used to monitor the progress (n = 24) and compared the findings in a subgroup of patients to a healthy control group. Performance on cancellation tasks, simple visual search, and self-reported responses on activities of daily living was compared, before and after training. Patients performed similarly well on NEC as on previous versions of the therapy; the inbuilt functionality for pre- and postevaluation functions was sensitive to allowing assessment of improvements; and improvements in patients were significantly greater than those in a group of healthy adults. In conclusion, NeuroEyeCoach can be used as an effective rehabilitation tool to develop compensatory strategies in patients with visual field deficits after brain injury.

The Effects of Short-Lasting Anti-Saccade Training in Homonymous Hemianopia with and without Saccadic Adaptation

Homonymous Visual Field Defects (HVFD) are common following stroke and can be highly debilitating for visual perception and higher level cognitive functions such as exploring visual scene or reading a text. Rehabilitation using oculomotor compensatory methods with automatic training over a short duration (~15 days) have been shown as efficient as longer voluntary training methods (>1 month). Here, we propose to evaluate and compare the effect of an original HVFD rehabilitation method based on a single 15 min voluntary anti-saccades task (AS) toward the blind hemifield, with automatic sensorimotor adaptation to increase AS amplitude. In order to distinguish between adaptation and training effect, 14 left- or right-HVFD patients were exposed, 1 month apart, to three trainings, two isolated AS task (Delayed-shift and No-shift paradigm), and one combined with AS adaptation (Adaptation paradigm). A quality of life questionnaire (NEI-VFQ 25) and functional measurements (reading speed, visual exploration time in pop-out and serial tasks) as well as oculomotor measurements were assessed before and after each training. We could not demonstrate significant adaptation at the group level, but we identified a group of nine adapted patients. While AS training itself proved to demonstrate significant functional improvements in the overall patient group, we could also demonstrate in the sub-group of adapted patients and specifically following the adaptation training, an increase of saccade amplitude during the reading task (left-HVFD patients) and the Serial exploration task, and improvement of the visual quality of life. We conclude that short-lasting AS training combined with adaptation could be implemented in rehabilitation methods of cognitive dysfunctions following HVFD. Indeed, both voluntary and automatic processes have shown interesting effects on the control of visually guided saccades in different cognitive tasks.

A study on the natural history of scanning behaviour in patients with visual field defects after stroke

Background

A visual field defect (VFD) is a common consequence of stroke with a detrimental effect upon the survivors’ functional ability and quality of life. The identification of effective treatments for VFD is a key priority relating to life post-stroke. Understanding the natural evolution of scanning compensation over time may have important ramifications for the development of efficacious therapies.

The study aims to unravel the natural history of visual scanning behaviour in patients with VFD. The assessment of scanning patterns in the acute to chronic stages of stroke will reveal who does and does not learn to compensate for vision loss.

Methods/Design

Eye-tracking glasses are used to delineate eye movements in a cohort of 100 stroke patients immediately after stroke, and additionally at 6 and 12 months post-stroke. The longitudinal study will assess eye movements in static (sitting) and dynamic (walking) conditions.

The primary outcome constitutes the change of lateral eye movements from the acute to chronic stages of stroke. Secondary outcomes include changes of lateral eye movements over time as a function of subgroup characteristics, such as side of VFD, stroke location, stroke severity and cognitive functioning.

Discussion

The longitudinal comparison of patients who do and do not learn compensatory scanning techniques may reveal important prognostic markers of natural recovery. Importantly, it may also help to determine the most effective treatment window for visual rehabilitation.

Eye-Search: A web-based therapy that improves visual search in hemianopia

Persisting hemianopia frequently complicates lesions of the posterior cerebral hemispheres, leaving patients impaired on a range of key activities of daily living. Practice-based therapies designed to induce compensatory eye movements can improve hemianopic patients' visual function, but are not readily available. We used a web-based therapy (Eye-Search) that retrains visual search saccades into patients' blind hemifield. A group of 78 suitable hemianopic patients took part. After therapy (800 trials over 11 days), search times into their impaired hemifield improved by an average of 24%. Patients also reported improvements in a subset of visually guided everyday activities, suggesting that Eye-Search therapy affects real-world outcomes.

The effect of saccadic training on early reading fluency

BACKGROUND

Eye movements are necessary for the physical act of reading and have been shown to relate to underlying cognitive and visuoattentional processes during reading. The purpose of this study was to determine the effect of saccadic training using the King-Devick remediation software on reading fluency.

METHODS

In this prospective, single-blinded, randomized, crossover trial, a cohort of elementary students received standardized reading fluency testing pre- and posttreatment. Treatment consisted of in-school training 20 minutes per day, 3 days per week for 6 weeks.

RESULTS

The treatment group had significantly higher reading fluency scores after treatment (P < .001), and posttreatment scores were significantly higher than the control group (P < .005).

CONCLUSION

Saccadic training can significantly improve reading fluency. We hypothesize that this improvement in reading fluency is a result of rigorous practice of eye movements and shifting visuospatial attention, which are vital to the act of reading.

Rehabilitation of damage to the visual brain

Homonymous visual field loss is a common consequence of stroke and traumatic brain injury. It is associated with an adverse functional prognosis and has implications on day-to-day activities such as driving, reading, and safe navigation. Early recovery is expected in around half of cases, and may be associated with a return in V1 activity. In stable disease, recovery is unlikely beyond 3 and certainly 6 months. Rehabilitative approaches generally target three main areas, encompassing a range of techniques with variable success: visual aids aim to expand or relocate the affected visual field; eye movement training builds upon compensatory strategies to improve explorative saccades; visual field restitution aims to improve visual processing within the damaged field itself. All these approaches seem to offer modest improvements with repeated practice, with none clearly superior to the rest. However, a number of areas are demonstrating particular promise currently, including simple web-based training initiatives, and work on neuroimaging and learning. The research interest in this area is encouraging, and it is to be hoped that future trials can better untangle and control for the number of complicated confounds, so that we will be in a much better position to evaluate and select the most appropriate therapy for patients.