Vision-Related Quality of Life in Patients with Complete Homonymous Hemianopia Post Stroke

Individualized functional magnetic resonance imaging neuromodulation enhances visuospatial perception: a proof-of-concept study

This proof-of-concept study uses individualized functional magnetic resonance imaging neuromodulation (iNM) to explore the mechanisms that enhance BOLD signals in visuospatial perception (VP) networks that are crucial for navigation. Healthy participants (n = 8) performed a VP up- and down-direction discrimination task at full and subthreshold coherence through peripheral vision, and superimposed direction through visual imagery (VI) at central space under iNM and control conditions. iNM targets individualized anatomical and functional middle- and medial-superior temporal (MST) networks that control VP. We found that iNM engaged selective exteroceptive and interoceptive attention (SEIA) and motor planning (MP) networks. Specifically, iNM increased overall: (i) area under the curve of the BOLD magnitude: 100% in VP (but decreased for weak coherences), 21-47% in VI, 26-59% in MP and 48-76% in SEIA through encoding; and (ii) classification performance for each direction, coherence and network through decoding, predicting stimuli from brain maps. Our findings, derived from encoding and decoding models, suggest that mechanisms induced by iNM are causally linked in enhancing visuospatial networks and demonstrate iNM as a feasibility treatment for low-vision patients with cortical blindness or visuospatial impairments that precede cognitive decline.This article is part of the theme issue 'Neurofeedback: new territories and neurocognitive mechanisms of endogenous neuromodulation'.

A systematic review on visual scanning behaviour in hemianopia considering task specificity, performance improvement, spontaneous and training-induced adaptations

PURPOSE

People with homonymous hemianopia (HH) benefit from applying compensatory scanning behaviour that limits the consequences of HH in a specific task. The aim of the study is to (i) review the current literature on task-specific scanning behaviour that improves performance and (ii) identify differences between this performance-enhancing scanning behaviour and scanning behaviour that is spontaneously adopted or acquired through training.

MATERIALS AND METHODS

The databases PsycInfo, Medline, and Web of Science were searched for articles on scanning behaviour in people with HH.

RESULTS

The final sample contained 60 articles, reporting on three main tasks, i.e., search (N = 17), reading (N = 16) and mobility (N = 14), and other tasks (N = 18). Five articles reported on two different tasks. Specific scanning behaviour related to task performance in search, reading, and mobility tasks. In search and reading tasks, spontaneous adaptations differed from this performance-enhancing scanning behaviour. Training could induce adaptations in scanning behaviour, enhancing performance in these two tasks. For mobility tasks, limited to no information was found on spontaneous and training-induced adaptations to scanning behaviour.

CONCLUSIONS

Performance-enhancing scanning behaviour is mainly task-specific. Spontaneous development of such scanning behaviour is rare. Luckily, current compensatory scanning training programs can induce such scanning behaviour, which confirms that providing scanning training is important.IMPLICATIONS FOR REHABILITATIONScanning behaviour that improves performance in people with homonymous hemianopia (HH) is task-specific.Most people with HH do not spontaneously adopt scanning behaviour that improves performance.Compensatory scanning training can induce performance-enhancing scanning behaviour.

Validation of the brain injury associated visual impairment - impact questionnaire (BIVI-IQ)

PURPOSE

The Brain Injury associated Visual Impairment - Impact Questionnaire (BIVI-IQ) was developed to assess the impact of post-stroke visual impairment. The development of the questionnaire used robust methods involving stroke survivors and clinicians. The aim of this study was to assess the validity of the BIVI-IQ in a stroke population.

METHODS

Stroke survivors with visual impairment were recruited from stroke units, outpatient clinics and non-healthcare settings. Participants were asked to complete questionnaire sets on three separate occasions; the BIVI-IQ at each visit with additional questionnaires at baseline and visit 2. Vision assessment and anchor questions from participants and clinicians were collected. The analysis included assessment of missing data, acceptability, Rasch model analysis, test-retest reliability, construct validity (NEI VFQ-25, EQ-5D-5L) and responsiveness to change.

RESULTS

316 stroke survivors completed at least one questionnaire of the 326 recruited. Mean age was 67 years and 64% were male. Adequate fit statistics to the Rasch model were reached (χ2 = 73.12, p = 0.02) with two items removed and thresholds of two adjusted, indicating validity and unidimensionality. Excellent test-retest reliability was demonstrated (ICC = 0.905) with a 3-month interval. Construct validity was demonstrated with a strong significant correlation to the NEI VFQ-25 (r = 0.837, p < 0.01). The BIVI-IQ also demonstrated responsiveness to change with significant differences identified between groups based on participant and clinician anchor questions (X2 = 23.29, p < 0.001; X2 = 24.56, p < 0.001).

CONCLUSION

The BIVI-IQ has been shown to be valid and practical for 'everyday' use by clinicians and researchers to monitor vision-related quality of life in stroke survivors with visual impairment.

Understanding viewpoint changes in peripheral prisms for field expansion by virtual reality simulation

Prism field expansion is a common treatment for patients with peripheral field loss, shifting images from the blind field into the seeing field. The shifted image originates from a new viewpoint translated and rotated from the original viewpoint by the prism. To understand such viewpoint changes, we simulated two field expansion methods in virtual reality: 1) angular (i.e., rotational) field expansion and 2) linear field expansion via image crop-and-shift. Changes to object locations, sizes, and optic flow patterns by those methods were demonstrated and analyzed in both static and dynamic conditions, which may affect navigation with such field expansion devices.

Oblique multi-periscopic prism for field expansion of homonymous hemianopia

Oblique Fresnel peripheral prisms have been used for field expansion in homonymous hemianopia mobility such as walking and driving. However, limited field expansion, low image quality, and small eye scanning range limit their effectiveness. We developed a new oblique multi-periscopic prism using a cascade of rotated half-penta prisms, which provides 42° horizontal field expansion along with 18° vertical shift, high image quality, and wider eye scanning range. Feasibility and performance of a prototype using 3D-printed module are demonstrated by raytracing, photographic depiction, and Goldmann perimetry with patients with homonymous hemianopia.

Development and 5-year Evaluation of Diagnosis-Specific Protocols for Visual Neuro-Rehabilitation in a Multicenter Inpatient Rehabilitation Network

Objective

To provide a retrospective evaluation of a new eye and vision rehabilitation care pathway in a U.S. multi-site inpatient rehabilitation network involving the occupational therapy (OT) staff and a consulting doctor of optometry (OD) specializing in vision rehabilitation.

Design

Retrospective study.

Setting

Two Inpatient Rehabilitation Facilities (IRFs) and 1 Long Term Acute Care Hospital (LTACH).

Participants

There were 2083 records reviewed (44% women, avg. age 59 years). The most common diagnoses were hemispatial neglect (19.2%), homonymous field defects (18.5%), and oculomotor cranial nerve palsies (16.7%) (N=2083).

Interventions

Clinical care was reviewed where diagnosis-specific protocols were developed and training was provided to OTs in order to reinforce OD-prescribed interventions during daily treatment sessions, including (1) third, fourth, and sixth ocular cranial nerve palsies (OCNPs) with prisms fitted for full time, postural adaptation training, and oculomotor re-education using pursuits, saccades, head-rotations, and binocular vision exercises including alternate cover and vergence; (2) homonymous hemianopia with training awareness of field loss, eccentric viewing, and fitting of Peli lens for optical field expansion; and (3) prism adaptation therapy (PAT) for left hemispatial neglect.

Main Outcome Measures

Frequency of diagnoses.

Hypothesis

Diagnoses with developed protocols were most common. Secondarily, feasibility and efficacy by anonymous OT survey.

Results

2083 vision consults were performed over 5 years. The most common diagnoses were hemispatial neglect (n=399, 19.2%), homonymous field defects (n=386, 18.5%), and OCNPs (n=347, 16.7%). None of the OTs reported the protocols were infeasible and 63% (IQR 38%-69%) reported their patients benefited from the interventions. The survey suggested prism for OCNPs helped in 42%, and Peli lens and PAT both helped in 38%.

Conclusions

Data support the feasibility of this inpatient eye and vision rehabilitation care pathway which may be used as a foundation for creating or refining similar programs elsewhere. Uniform administration of IRF-based visual neuro-rehabilitation care could provide a substrate for future clinical trials to evaluate efficacy.

The impact of low vision on activities, participation, and goals among older adults: a scoping review

PURPOSE

Participation is a key outcome of rehabilitation. However, no reviews have investigated the impact of low vision on the activities, participation, and goals of older adults. This paper aims to review and synthesize available literature on how low vision impacts the activity and participation of older adults.

METHOD

A scoping review was conducted. The key findings were extracted from 30 full-text articles that met the selection criteria. The International Classification of Functioning, Disability and Health was used to frame the findings at the activity and participation levels.

RESULTS

At the activity level, the categories of Walking, Moving around in different locations, and Reading were commonly impacted by low vision. The main domains impacted at the participation level were Community, social and civic life and Interpersonal interaction and relationships. Only one study addressed the goals of older adults with low vision.

CONCLUSION

Low vision impacts reading, walking, and moving around in different locations. Rehabilitation therapists should be aware of and consider assessing these activities. Further research is needed on the impact of low vision on other functional activities, participation, and self-identified goals of older adults to guide clinical practice.Implications for rehabilitationLow vision has an impact on the activity level of older adults, consistently identified in the areas of walking and moving around in different locations and reading for knowledge and leisure.At the participation level, the impact of low vision is less frequently identified compared to the areas identified at the activity level, in the areas of leisure, social interactions and basic and instrumental ADL.Rehabilitation therapists working with older adults with low vision should assess clients' performance of moving around in different locations, in addition to walking, and include screening questions on the impact of low vision on driving.Rehabilitation therapists working with older adults with low vision should determine clients' reading needs and acquire competence in assessing clients' reading ability and providing intervention for different types of reading to enable them to continue participating in various life situations that require the performance of reading.

Visual mapping for tumor resection: A proof of concept of a new intraoperative task and a systematic review of the literature

Homonymous hemianopia has been reported after brain tumor resection with a significant impact on quality of life. Nevertheless, no standardized methods exist for intraoperative optical radiations mapping. The purpose of this article is to describe a new intraoperative task for visual mapping and to review the existing literature.

Impact of visual field loss post-stroke on activities of daily living: a prospective cohort study

This study investigated the ADL performances of people with VFL after an acute stroke using an observation-based evaluation of ADL skills, the Assessment of Motor and Process Skills. The AMPS was administered on initial assessment and at ≥11 weeks follow-up on 58 adults with a mild stroke, with (n = 16) and without VFL (n = 42), over a 13-month period. The AMPS guidelines on clinically relevant difference of 0.30 logits were used to determine the differences of the groups' ADL performance on initial assessment and follow-up. The study found that the ADL motor and process scores did not differ significantly on initial assessment. The study observed no clinically relevant difference between the ADL motor and process scores of between the VFL and non-VFL on initial assessment and follow-up but demonstrated clinically relevant improvements in ADL motor and process scores of both groups from initial assessment to follow-up. VFL does not have an additional negative impact on ADL performance of those with a mild stroke and does not impede improvement of ADL performance over time.

Benefits of Endogenous Spatial Attention During Visual Double-Training in Cortically-Blinded Fields

Recovery of visual discrimination thresholds inside cortically-blinded (CB) fields is most commonly attained at a single, trained location at a time, with iterative progress deeper into the blind field as performance improves over several months. As such, training is slow, inefficient, burdensome, and often frustrating for patients. Here, we investigated whether double-location training, coupled with a covert spatial-attention (SA) pre-cue, could improve the efficiency of training. Nine CB participants completed a randomized, training assignment with either a spatial attention or neutral pre-cue. All trained for a similar length of time on a fine direction discrimination task at two blind field locations simultaneously. Training stimuli and tasks for both cohorts were identical, save for the presence of a central pre-cue, to manipulate endogenous (voluntary) SA, or a Neutral pre-cue. Participants in the SA training cohort demonstrated marked improvements in direction discrimination thresholds, albeit not to normal/intact-field levels; participants in the Neutral training cohort remained impaired. Thus, double-training within cortically blind fields, when coupled with SA pre-cues can significantly improve direction discrimination thresholds at two locations simultaneously, offering a new method to improve performance and reduce the training burden for CB patients. Double-training without SA pre-cues revealed a hitherto unrecognized limitation of cortically-blind visual systems’ ability to improve while processing two stimuli simultaneously. These data could potentially explain why exposure to the typically complex visual environments encountered in everyday life is insufficient to induce visual recovery in CB patients. It is hoped that these new insights will direct both research and therapeutic developments toward methods that can attain better, faster recovery of vision in CB fields.

Mid-range visual deficits after stroke: Prevalence and co-occurrence

Visual deficits are common after stroke and are powerful predictors for the chronic functional outcome. However, while basic visual field and recognition deficits are relatively easy to assess with standardized methods, selective deficits in visual primitives, such as shape or motion, are harder to identify, as they often require a symmetrical bilateral posterior lesion in order to provoke full field deficits. Therefore, we do not know how often they occur. Nevertheless, they can have severe repercussions for daily-life functioning. We aimed to investigate the prevalence and co-occurrence of hemifield “mid-range” visual deficits (i.e. color, shape, location, orientation, correlated motion, contrast, texture and glossiness), using a novel experimental set-up with a gaze-contingent presentation of the stimuli. To this end, a prospective cohort of 220 ischemic (sub)cortical stroke patients and a healthy control group was assessed with this set-up. When comparing performance of patients with controls, the results showed that deficits in motion-perception were most prevalent (26%), followed by color (22%), texture (22%), location (21%), orientation (18%), contrast (14%), shape (14%) and glossiness (13%). 63% of the stroke patients showed one or more mid-range visual deficits. Overlap of deficits was small; they mostly occurred in isolation or co-occurred with only one or two other deficits. To conclude, it was found that deficits in “mid-range” visual functions were very prevalent. These deficits are likely to affect the chronic post-stroke condition. Since we found no strong patterns of co-occurrences, we suggest that an assessment of deficits at this level of visual processing requires screening the full range of visual functions.

Binocular Visual Field and Vision-Related Quality of Life in Patients With Hemianopia

BACKGROUND

Hemianopias can have a severe impact on functional ability and quality of life (QoL). Binocular visual field (VF) analysis is clinically more relevant to visual function than monocular VF. The aim is to analyze the binocular VF of patients with hemianopias and its association with the monocular VF and to assess the QoL of these patients through questionnaires specifically related to vision compared with healthy controls.

METHODS

The case-control study included patients with hemianopias and controls. Sex, age, general history, etiology, location of the lesion, and time since the lesion appeared were recorded. Monocular VF and Esterman binocular VF were performed. VF defect, mean defect (MD), and Esterman scores were recorded. Visual Activities Questionnaire (VAQ-33) and Visual Function Questionnaire (VFQ-25) questionnaires were administered.

RESULTS

Twenty patients with hemianopia and 22 healthy controls were included. The Esterman score in homonymous hemianopia patients (n = 17) correlated with best eye MD (r = -0.62, P = 0.01), worst eye MD (r = -0.70, P = 0.002), and average MD (r = -0.68, P = 0.003). Compared with healthy control subjects, patients with homonymous hemianopia had significantly lower VFQ-25 score and in 10/12 subscales (all P < 0.001). VAQ-33 scores revealed lower overall and subscales scores with the exception of light/dark adaptation (P = 0.08). Correlations were found between monocular and binocular VF scores and general vision (r = -0.55), peripheral vision (on both questionnaires, r-range -0.75 to 0.47), VFQ-25 and VAQ-33 overall scores (r = -0.59, -0.49 and 0.50), and glare disability (r = 0.53 and 0.67).

CONCLUSIONS

Hemianopic VF defects involve a major alteration in the patients' vision-related QoL.

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.

Inpatient Virtual Vision Clinic Improves Access to Vision Rehabilitation Before and During the COVID-19 Pandemic

OBJECTIVE

To describe and evaluate a secure video call system combined with a suite of iPad vision testing apps to improve access to vision rehabilitation assessment for inpatients.

DESIGN

Retrospective.

SETTING

Two acute care inpatient rehabilitation hospitals and 1 long-term acute care (LTAC) hospital.

PARTICIPANTS

Records of inpatients seen by the vision service.

INTERVENTIONS

Records from a 1-year telemedicine pilot performed at acute rehabilitation (AR) hospital 1 and then expanded to AR hospital 2 and LTAC hospital during coronavirus disease 2019 (COVID-19) were reviewed. In the virtual visits, an occupational therapist measured the patients' vision with the iPad applications and forwarded results to the off-site Doctor of Optometry (OD) for review prior to a video visit. The OD provided diagnosis and education, press-on prism application supervision, strategies and modifications, and follow-up recommendations. Providers completed the telehealth usability questionnaire (10-point scale).

MAIN OUTCOME MEASURES

Vision examinations per month at AR hospital 1 before and with telemedicine.

RESULTS

With telemedicine at AR hospital 1, mean visits per month significantly increased from 10.7±5 to 14.9±5 (P=.002). Prism was trialed in 40% of cases of which 83% were successful, similar to previously reported in-person success rates. COVID-19 caused only a marginal decrease in visits per month (P=.08) at AR1, whereas the site without an established program (AR hospital 2) had a 3-4 week gap in care while the program was initiated. Cases at the LTAC hospital tended to be more complex and difficult to manage virtually. The telehealth usability questionnaire median category scores were 7 for Ease of Use, 8 for Interface Quality, 6 for Reliability, and 9 for Satisfaction and Future Use.

CONCLUSIONS

The virtual vision clinic process improved inpatient access to eye and visual neurorehabilitation assessment before and during the COVID-19 quarantine and was well accepted by providers and patients.

Maximizing Telerehabilitation for Patients With Visual Loss After Stroke: Interview and Focus Group Study With Stroke Survivors, Carers, and Occupational Therapists

BACKGROUND

Visual field defects are a common consequence of stroke, and compensatory eye movement strategies have been identified as the most promising rehabilitation option. There has been a move toward compensatory telerehabilitation options, such as the Durham Reading and Exploration (DREX) training app, which significantly improves visual exploration, reading, and self-reported quality of life.

OBJECTIVE

This study details an iterative process of liaising with stroke survivors, carers, and health care professionals to identify barriers and facilitators to using rehabilitation tools, as well as elements of good practice in telerehabilitation, with a focus on how the DREX package can be maximized.

METHODS

Survey data from 75 stroke survivors informed 12 semistructured engagement activities (7 focus groups and 5 interviews) with 32 stroke survivors, 10 carers, and 24 occupational therapists.

RESULTS

Thematic analysis identified key themes within the data. Themes identified problems associated with poststroke health care from both patients' and occupational therapists' perspectives that need to be addressed to improve uptake of this rehabilitation tool and telerehabilitation options generally. This included identifying additional materials or assistance that were required to boost the impact of training packages. The acute rehabilitation setting was an identified barrier, and perceptions of technology were considered a barrier by some but a facilitator by others. In addition, 4 key features of telerehabilitation were identified: additional materials, the importance of goal setting, repetition, and feedback.

CONCLUSIONS

The data were used to try to overcome some barriers to the DREX training and are further discussed as considerations for telerehabilitation in general moving forward.

2017 Charles F. Prentice Award Lecture: Peripheral Prisms for Visual Field Expansion: A Translational Journey

On the occasion of being awarded the Prentice Medal, I was asked to summarize my translational journey. Here I describe the process of becoming a low-vision rehabilitation clinician and researcher, frustrated by the unavailability of effective treatments for some conditions. This led to decades of working to understand patients' needs and the complexities and subtleties of their visual systems and conditions. It was followed by many iterations of developing vision aids and the techniques needed to objectively evaluate their benefit. I specifically address one path: the invention and development of peripheral prisms to expand the visual fields of patients with homonymous hemianopia, leading to our latest multiperiscopic prism (mirror-based design) with its clear 45° field-of-view image shift.

Multi-periscopic prism device for field expansion

Patients with visual field loss frequently collide with other pedestrians, with the highest risk being from pedestrians at a bearing angle of 45°. Current prismatic field expansion devices (≈30°) cannot cover pedestrians posing the highest risk and are limited by poor image quality and restricted eye scanning range (<5°). A new field expansion device: multi-periscopic prism (MPP); comprising a cascade of half-penta prisms provides wider shifting power (45°) with dramatically better image quality and wider eye scanning range (15°) is presented. Spectacles-mounted MPPs were implemented using 3D printing. The efficacy of the MPP is demonstrated using perimetry, photographic depiction, and analyses of the collision risk covered by the devices.

Vision Screening Assessment (VISA) tool: diagnostic accuracy validation of a novel screening tool in detecting visual impairment among stroke survivors

PURPOSE

Screening for visual problems in stroke survivors is not standardised. Visual problems that remain undetected or poorly identified can create unmet needs for stroke survivors. We report the validation of a new Vision Impairment Screening Assessment (VISA) tool intended for use by the stroke team to improve identification of visual impairment in stroke survivors.

METHODS

We conducted a prospective case cohort comparative study in four centres to validate the VISA tool against a specialist reference vision assessment. VISA is available in print or as an app (Medicines and Healthcare products Regulatory Agency regulatory approved); these were used equally for two groups. Both VISA and the comprehensive reference vision assessment measured case history, visual acuity, eye alignment, eye movements, visual field and visual inattention. The primary outcome measure was the presence or absence of visual impairment.

RESULTS

Two hundred and twenty-one stroke survivors were screened. Specialist reference vision assessment was by experienced orthoptists. Full completion of screening and reference vision assessment was achieved for 201 stroke survivors. VISA print was completed for 101 stroke survivors; VISA app was completed for 100. Sensitivity and specificity of VISA print was 97.67% and 66.67%, respectively. Overall agreement was substantial; K=0.648. Sensitivity and specificity of VISA app was 88.31% and 86.96%, respectively. Overall agreement was substantial; K=0.690. Lowest agreement was found for screening of eye movement and near visual acuity.

CONCLUSIONS

This validation study indicates acceptability of VISA for screening of potential visual impairment in stroke survivors. Sensitivity and specificity were high indicating the accuracy of this screening tool. VISA is available in print or as an app allowing versatile uptake across multiple stroke settings.

Vision-related quality of life in patients with occipital stroke

OBJECTIVES

The aim of this study was to detect visual field defects (VFDs) after occipital infarction, investigate the rate of recovery and the impact of VFD upon vision-related quality of life (QoL).

MATERIALS AND METHODS

Multicenter, prospective study including patients with MRI verified acute occipital infarction (NOR-OCCIP project). Ophthalmological examination including perimetry was performed within 2 weeks and after 6 months. Vision-related QoL was assessed by the National Eye Institute Visual Function Questionnaire 25 (VFQ-25) at one and 6 months post-stroke.

RESULTS

We included 76 patients, reliable perimetry results were obtained in 66 patients (87%) at a median of 8 days after admittance and VFD were found in 52 cases (79%). Evaluation of VFD after 6 months revealed improvement in 52%. Patients with VFD had significantly lower composite score in VFQ-25 at both test points (77 vs 96, P = .001 and 87 vs 97, P = .009), in nine out of eleven subscales of VFQ-25 at 1 month and seven subscales after 6 months, including mental health, dependency, near and distance activities. Milder VFD had better results on VFQ-25 modified composite score (95 vs 74, P = .002).VFD improvement was related to improved VFQ-25 modified composite score (9.6 vs 0.8, P = .018). About 10% of patients with VFD reported driving 1 month post-stroke and 38% after 6 months.

CONCLUSION

VFD substantially reduces multiple aspects of vision-related QoL. Severity of VFD is related to QoL and VFD improvement results in better QoL. Neglecting visual impairment after stroke may result in deterioration of rehabilitation efforts. Driving post-stroke deserves particular attention.

Perspectives: Hemianopia-Toward Novel Treatment Options Based on Oscillatory Activity?

Stroke has become one of the main causes of visual impairment, with more than 15 million incidences of first-time strokes, per year, worldwide. One-third of stroke survivors exhibit visual impairment, and most of them will not fully recover. Some recovery is possible, but this usually happens in the first few weeks after a stroke. Most of the rehabilitation options that are offered to patients are compensatory, such as optical aids or eye training. However, these techniques do not seem to provide a sufficient amount of improvement transferable to everyday life. Based on the relatively recent idea that the visual system can actually recover from a chronic lesion, visual retraining protocols have emerged, sometimes even in combination with noninvasive brain stimulation (NIBS), to further boost plastic changes in the residual visual tracts and network. The present article reviews the underlying mechanisms supporting visual retraining and describes the first clinical trials that applied NIBS combined with visual retraining. As a further perspective, it gathers the scientific evidence demonstrating the relevance of interregional functional synchronization of brain networks for visual field recovery, especially the causal role of α and γ oscillations in parieto-occipital regions. Because transcranial alternating current stimulation (tACS) can induce frequency-specific entrainment and modulate spike timing-dependent plasticity, we present a new promising interventional approach, consisting of applying physiologically motivated tACS protocols based on multifocal cross-frequency brain stimulation of the visuoattentional network for visual field recovery.

The Effects of Hemianopia on Perception of Mutual Gaze

SIGNIFICANCE

Individuals with left hemianopic field loss (HFL), especially with neglect history, may have greater difficulties than individuals with right HFL in judging the direction of another person's gaze.

PURPOSE

Individuals with HFL often show a spatial bias in laboratory-based perceptual tasks. We investigated whether such biases also manifest in a more real-world task, perception of mutual gaze direction, an important, nonverbal communication cue in social interactions.

METHODS

Participants adjusted the eye position of a life-size virtual head on a monitor at a 1-m distance until (1) the eyes appeared to be looking straight at them, or (2) the eyes were perceived to be no longer looking at them (to the right and left).

RESULTS

Participants with right HFL (n = 8) demonstrated a rightward error in line bisection but made gaze judgments within the range of normally sighted controls (n = 17). Participants with left HFL without neglect history (n = 6) made leftward errors in line bisection and had more variable gaze judgments; three had estimates of gaze direction outside the reference range. Four participants with left HFL and neglect history made estimates of gaze direction that were to the right of the reference range.

CONCLUSIONS

Our results suggest that individuals with left HFL, especially with neglect history, may have greater difficulties than individuals with right HFL in compensating for low-level spatial biases (as manifested in line bisection) when performing the more complex, higher-level task of judging gaze direction.

Visual Function Questionnaire as an outcome measure for homonymous hemianopia: subscales and supplementary questions, analysis from the VISION trial

BACKGROUND

We conduct supplementary analyses of the NEI VFQ-25 data to evaluate where changes occurred within subscales of the NEI VFQ-25 leading to change in the composite scores between the three treatment arms, and evaluate the NEI VFQ-25 with and without the Neuro 10 supplement.

METHODS

A prospective, multicentre, parallel, single-blind, three-arm RCT of fourteen UK acute stroke units was conducted. Stroke survivors with homonymous hemianopia were recruited. Interventions included: Fresnel prisms for minimum 2 h, 5 days/week over 6-weeks (Arm a), Visual search training for minimum 30 min, 5 days/week over 6-weeks (Arm b) and standard care-information only (Arm c). Primary and secondary outcomes (including NEI VFQ-25 data) were measured at baseline, 6, 12 and 26 weeks after randomisation.

RESULTS

Eighty seven patients were recruited (69% male; mean age (SD) equal to 69 (12) years). At 26 weeks, outcomes for 24, 24 and 22 patients, respectively, were compared to baseline. NEI VFQ-25 (with and without Neuro 10) responses improved from baseline to 26 weeks with visual search training compared to Fresnel prisms and standard care. In subscale analysis, the most impacted across all treatment arms was 'driving' whilst the least impacted were 'colour vision' and 'ocular pain'.

CONCLUSIONS

Composite scores differed systematically for the NEI VFQ-25 (Neuro 10) versus NEI VFQ-25 at all time points. For subscale scores, descriptive statistics suggest clinically relevant improvement in distance activities and vision-specific dependency subscales for NEI VFQ-25 scores in the visual search treatment arm.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN05956042.

Development of a patient reported outcome measures for measuring the impact of visual impairment following stroke

BACKGROUND

Among the available patient-reported outcome measures (PROMs) there is an absence of a PROM with a specific focus on the impact of the wide variety of visual impairments following stroke. Our aim was to develop a patient reported quality of life outcome measure for stroke survivors with visual impairment.

METHODS

Potential items were sourced from a combination of existing PROMs from a systematic review and qualitative in-depth interviews, duplicates were removed and items shortlisted. The initial pilot instrument was created following a ranking exercise of these potential items and consultation with stroke survivors. Version 1 was piloted with 37 stroke survivors at acute and chronic stages. Version 2 was piloted with 243 stroke survivors with visual impairment at acute and chronic stages. This data was analysed using the Rasch measurement model. Simultaneously, items from Version 2 underwent a Delphi process with stroke survivors and stroke clinicians, to assess the importance of each item. Final consensus decisions on item removal were made using the combined analysis from the Rasch measurement model and Delphi process in a nominal group meeting.

RESULTS

Due to the wide range of rank given to the majority of categories/items, only two items were discarded. Version 1 comprised of 102 items with 5 response categories relating to amount of difficulty. The pilot of Version 1 allowed item reduction based on analysis of floor/ceiling effects and not applicable responses. Version 2 comprised of 62 items. Within the nominal group meeting, the expert panel created a set of rules which aided them with decision making in addition to the Rasch and Delphi analysis data. This resulted in the removal of 43 items and the combination of seven items to create three new items. The expert panel also recommended the rewording of three items.

CONCLUSION

The Brain Injury associated Visual Impairment Impact Questionnaire (BIVI-IQ-15), a 15-item instrument with 4 response categories has been developed for capturing vision-related quality of life of stroke survivors with any of the predominant types of visual impairment, in the presence of other impairments and for both inpatients and outpatients.

A qualitative exploration of the effect of visual field loss on daily life in home-dwelling stroke survivors

OBJECTIVE

To explore the effect of visual field loss on the daily life of community-dwelling stroke survivors.

DESIGN

A qualitative interview study.

PARTICIPANTS

Adult stroke survivors with visual field loss of at least six months' duration.

METHODS

Semi-structured interviews were conducted with a non-purposive sample of 12 stroke survivors in their own homes. These were recorded, transcribed verbatim and analyzed with the framework method, using an inductive approach.

RESULTS

Two key analytical themes emerged. 'Perception, experience and knowledge' describes participant's conflicted experience of having knowledge of their impaired vision but lacking perception of that visual field loss and operating under the assumption that they were viewing an intact visual scene when engaged in activities. Inability to recognize and deal with visual difficulties, and experiencing the consequences, contributed to their fear and loss of self-confidence. 'Avoidance and adaptation' were two typologies of participant response to visual field loss. Initially, all participants consciously avoided activities. Some later adapted to vision loss using self-directed head and eye scanning techniques.

CONCLUSIONS

Visual field loss has a marked impact on stroke survivors. Stroke survivors lack perception of their visual loss in everyday life, resulting in fear and loss of confidence. Activity avoidance is a common response, but in some, it is replaced by self-initiated adaptive techniques.

High incidence and prevalence of visual problems after acute stroke: An epidemiology study with implications for service delivery

Background

Visual problems are an under-reported sequela following stroke. The aim of this study is to report annual incidence and point prevalence of visual problems in an acute adult stroke population and to explore feasibility of early timing of visual assessment.

Methods and findings

Multi-centre acute stroke unit, prospective, epidemiology study (1^st July 2014 to 30^th June 2015). Orthoptists reviewed all patients with assessment of visual acuity, visual fields, ocular alignment, ocular motility, visual inattention and visual perception. 1033 patients underwent visual screening at a median of 3 days (IQR 2) and full visual assessment at a median of 4 days (IQR 7) after the incident stroke: 52% men, 48% women, mean age 73 years and 87% ischaemic strokes. Excluding pre-existent eye problems, the incidence of new onset visual sequelae was 48% for all stroke admissions and 60% in stroke survivors. Three quarters 752/1033 (73%) had visual problems (point prevalence): 56% with impaired central vision, 40% eye movement abnormalities, 28% visual field loss, 27% visual inattention, 5% visual perceptual disorders. 281/1033 (27%) had normal eye exams.

Conclusions

Incidence and point prevalence of visual problems in acute stroke is alarmingly high, affecting over half the survivors. For most, visual screening and full visual assessment was achieved within about 5 days of stroke onset. Crucial information can thus be provided on visual status and its functional significance to the stroke team, patients and carers, enabling early intervention.

Using Vision to Study Poststroke Recovery and Test Hypotheses About Neurorehabilitation

Approximately one-third of stroke patients suffer visual field impairment as a result of their strokes. However, studies using the visual pathway as a paradigm for studying poststroke recovery are limited. In this article, we propose that the visual pathway has many features that make it an excellent model system for studying poststroke neuroplasticity and assessing the efficacy of therapeutic interventions. First, the functional anatomy of the visual pathway is well characterized, which makes it well suited for functional neuroimaging studies of poststroke recovery. Second, there are multiple highly standardized and clinically available diagnostic tools and outcome measures that can be used to assess visual function in stroke patients. Finally, as a sensory modality, the assessment of vision is arguably less likely to be affected by confounding factors such as functional compensation and patient motivation. Given these advantages, and the general similarities between poststroke visual field recovery and recovery in other functional domains, future neurorehabilitation studies should consider using the visual pathway to better understand the physiology of neurorecovery and test potential therapeutics.

Outcomes After Comprehensive Vision Rehabilitation Using Vision-related Quality of Life Questionnaires: Impact of Vision Impairment and National Eye Institute Visual Functioning Questionnaire

SIGNIFICANCE

This research is significant because, although vision-related quality of life (VRQoL) is improved after vision rehabilitation (VR), patients with certain characteristics respond less positively on VRQoL measures, and this should inform future care.

PURPOSE

The purposes of this study were to evaluate how two VRQoL questionnaires compare in measuring change in patient-reported outcomes after VR and to determine if patient characteristics or occupational therapy (OT) predict higher scores after rehabilitation.

METHODS

In a prospective clinical cohort study, 109 patients with low vision completed the Impact of Vision Impairment (IVI) and the National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) before and after VR. Comprehensive VR included consultation with an ophthalmologist and OT if required. The relationships of six baseline characteristics (age, sex, visual acuity, contrast sensitivity, field loss, diagnosis) and OT were assessed with VRQoL scores using multivariable logistic regression.

RESULTS

The mean (SD) age was 68.5 (19.2) years, and 61 (56%) were female. After rehabilitation, increases in scores were observed in all IVI subscales (reading [P < .001], mobility [P = .002], well-being [P = .0003]) and all NEI VFQ-25 subscales (functional [P = .01], socioemotional [P = .003]). Those who were referred to OT but did not attend and those who had hemianopia/field loss were less likely to have higher VRQoL in IVI mobility and well-being. Those attending OT for more than 3 hours were less likely to have better scores in emotional NEI VFQ. Men were less likely to have increased scores in functional and emotional NEI VFQ, whereas those with diagnoses of nonmacular diseases had higher odds of having increased scores on the emotional NEI VFQ (all, P < .05).

CONCLUSION

Both the IVI and the NEI VFQ-25 detected change in patients' VRQoL after rehabilitation. Most of the patient characteristics we considered predicted a lower likelihood of increased scores in VRQoL.

Scanning training for rehabilitation of visual field loss due to stroke: Identifying and exploring training tools in use

Introduction

Visual field loss affects one fifth of stroke survivors, limiting daily activities and reducing quality of life. Scanning training is a commonly used intervention, but there is variation in how this is delivered. This study aimed to identify the scanning training tools used in Scotland and describe their training parameters, delivery and suitability for use with stroke survivors.

Method

An email survey identified scanning training tools used in Scotland. Two expert panel meetings gained consensus on the motor, language and cognitive skills required to use each scanning training tool. Video capture techniques gathered objective measures of training parameters.

Results

Ten scanning training tools were identified. These tools used four delivery methods: paper-based, computer software, web-based and specialised equipment. They aimed to improve reading, perception or general visual skills. Fast, saccadic eye movements were most frequently targeted: two interventions also encouraged head movements. Session duration, frequency and therapist support varied considerably. The level of motor, language and cognitive skills required for each tool was determined.

Conclusion

Scanning training tools used in Scotland vary in delivery modality, functional abilities required for use and visual skills trained. This information will support clinical decision-making and inform future research on training effectiveness and feasibility.

A Systematic Review and Meta-Analysis of Rehabilitative Interventions for Unilateral Spatial Neglect and Hemianopia Poststroke From 2006 Through 2016

OBJECTIVE

To evaluate the effectiveness of activity-based, nonactivity-based, and combined activity- and nonactivity-based rehabilitative interventions for individuals presenting with unilateral spatial neglect (USN) and hemianopia.

DATA SOURCES

We searched CINAHL, Cochrane Library, EMBASE, MEDLINE, and PubMed from 2006 to 2016.

STUDY SELECTION

Randomized controlled trials (RCTs) with a score of 6 or more in the Physiotherapy Evidence Database Scale that examined the effects of activity-based and nonactivity-based rehabilitation interventions for people with USN or hemianopia. Two reviewers selected studies independently.

DATA EXTRACTION

Extracted data from the published RCTs. Mean differences (MD) or standardized mean differences (SMD), and 95% confidence intervals (CIs) were calculated. Heterogeneity was assessed using the I² statistic.

DATA SYNTHESIS

A total of 20 RCTs for USN and 5 for hemianopia, involving 594 and 206 stroke participants respectively, were identified. Encouraging results were found in relation to activity-based interventions for visual scanning training and compensatory training for hemianopia (MD=5.11; 95% confidence intervals [95% CI], 0.83-9.4; P=.019; I²=25.16% on visual outcomes), and optokinetic stimulation and smooth pursuit training for USN (SMD=0.49; 95% CI, 0.01-0.97; P=.045; I²=49.35%) on functional performance in activities of daily living, (SMD=0.96; 95% CI, 0.09-1.82; P=.031; I²=89.57%) on neglect.

CONCLUSIONS

Activity-based interventions are effective and commonly used in the treatment of USN and hemianopia. Nonactivity-based and combined approaches, for both impairments, have not been refuted, because more studies are required for substantiated conclusions to be drawn.

Measuring the Difficulty Watching Video With Hemianopia and an Initial Test of a Rehabilitation Approach

PURPOSE

If you cannot follow the story when watching a video, then the viewing experience is degraded. We measured the difficulty of following the story, defined as the ability to acquire visual information, which is experienced by people with homonymous hemianopia (HH). Further, we proposed and tested a novel rehabilitation aid.

METHODS

Participants watched 30-second directed video clips. Following each video clip, subjects described the visual content of the clip. An objective score of information acquisition (IA) was derived by comparing each new response to a control database of descriptions of the same clip using natural language processing. Study 1 compared 60 participants with normal vision (NV) to 24 participants with HH to test the hypothesis that participants with HH would score lower than NV participants, consistent with reports from people with HH that describe difficulties in video watching. In the second study, 21 participants with HH viewed clips with or without a superimposed dynamic cue that we called a content guide. We hypothesized that IA scores would increase using this content guide.

RESULTS

The HH group had a significantly lower IA score, with an average of 2.8, compared with 4.3 shared words of the NV group (mixed-effects regression, P < 0.001). Presence of the content guide significantly increased the IA score by 0.5 shared words (P = 0.03).

CONCLUSIONS

Participants with HH had more difficulty acquiring information from a video, which was objectively demonstrated (reduced IA score). The content guide improved information acquisition, but not to the level of people with NV.

TRANSLATIONAL RELEVANCE

The value as a possible rehabilitation aid of the content guide warrants further study that involves an extended period of content-guide use and a randomized controlled trial.

People with Hemianopia Report Difficulty with TV, Computer, Cinema Use, and Photography

SIGNIFICANCE

Our survey found that participants with hemianopia report more difficulties watching video in various formats, including television (TV), on computers, and in a movie theater, compared with participants with normal vision (NV). These reported difficulties were not as marked as those reported by people with central vision loss.

PURPOSE

The aim of this study was to survey the viewing experience (e.g., frequency, difficulty) of viewing video on TV, computers and portable visual display devices, and at the cinema of people with hemianopia and NV. This information may guide vision rehabilitation.

METHODS

We administered a cross-sectional survey to investigate the viewing habits of people with hemianopia (n = 91) or NV (n = 192). The survey, consisting of 22 items, was administered either in person or in a telephone interview. Descriptive statistics are reported.

RESULTS

There were five major differences between the hemianopia and NV groups. Many participants with hemianopia reported (1) at least "some" difficulty watching TV (39/82); (2) at least "some" difficulty watching video on a computer (16/62); (3) never attending the cinema (30/87); (4) at least some difficulty watching movies in the cinema (20/56), among those who did attend the cinema; and (5) never taking photographs (24/80). Some people with hemianopia reported methods that they used to help them watch video, including video playback and head turn.

CONCLUSIONS

Although people with hemianopia report more difficulty with viewing video on TV and at the cinema, we are not aware of any rehabilitation methods specifically designed to assist people with hemianopia to watch video. The results of this survey may guide future vision rehabilitation.

Using Delphi methodology in the development of a new patient-reported outcome measure for stroke survivors with visual impairment

Introduction

The aim of this study was to ascertain what items stroke survivors and stroke care professionals think are important when assessing quality of life for stroke survivors with visual impairment for inclusion in the new patient-reported outcome measure.

Methods

A reactive Delphi process was used in a three-round electronic-based survey. The items presented consisted of 62 items originally sourced from a systematic review of existing vision-related quality of life instruments and stroke survivor interviews, reduced and refined following a ranking exercise and pilot with stroke survivors with visual impairment. Stakeholders (stroke survivors/clinicians) were invited to take part in the process. A consensus definition of ≥70% was decided a priori. Participants were asked to rank importance on a 9-point scale and categorize the items by relevance to types of visual impairment following stroke or not relevant. Analysis of consensus, stability, and agreement was conducted.

Results

In total, 113 participants registered for the Delphi survey of which 47 (41.6%) completed all three rounds. Response rates to the three rounds were 78/113 (69.0%), 61/76 (81.3%), and 49/64 (76.6%), respectively. The participants included orthoptists (45.4%), occupational therapists (44.3%), and stroke survivors (10.3%). Consensus was reached on 56.5% of items in the three-round process, all for inclusion. A consensus was reached for 83.8% in the categorization of items. The majority (82.6%) of consensus were for relevant to 'all visual impairment following stroke'; two items were deemed 'not relevant'.

Conclusion

The lack of item reduction achieved by this Delphi process highlights the need for additional methods of item reduction in the development of a new PROM for visual impairment following stroke. These results will be considered alongside Rasch analysis to achieve further item reduction. However, the Delphi survey remains important as it provides clinical and patient insight into each item rather than purely relying on the psychometric data.

Novel mobility test to assess functional vision in patients with inherited retinal dystrophies

IMPORTANCE

This novel endpoint tracks functional vision changes in patients with inherited retinal dystrophies (IRDs) over time.

BACKGROUND

The aims of the study were to determine whether a multi-luminance mobility test (MLMT) can detect functional vision changes over time in subjects with IRDs and to assess natural history and potential effects of investigational agents.

DESIGN

This is a prospective, observational study.

PARTICIPANTS

Sixty-two subjects were enrolled. Sixty (29 normal sighted and 31 visually impaired) were eligible; 54 (28 visually impaired and 26 normal-sighted) completed all testing visits.

METHODS

Subjects navigated MLMT courses three times over 1 year. At each visit, subjects completed testing using individual eyes, and both eyes, at up to nine standardized, increasing luminance levels (range 1 to 400 lux). Accuracy and speed were evaluated and compared with visual acuity (VA), visual field (VF) and a visual function questionnaire.

MAIN OUTCOME MEASURES

Accuracy and speed of normal and visually impaired subjects on MLMT, and reliability and content validity of MLMT were the main outcome measures.

RESULTS

MLMT distinguished normal-sighted from visually impaired subjects. All control subjects passed all MLMT attempts at all tested light levels. Visually impaired subjects' performance varied widely; some declined over 1 year. Performance declined markedly below certain VA and VF thresholds. Concordance on performance on two baseline visits was high: correlations for accuracy were 94% and 98% for lowest common and highest common lux levels.

CONCLUSIONS AND RELEVANCE

MLMT differentiated visually impaired from control populations and, in visually impaired subjects, identified a range of performances; and tracked performance declines over time, consistent with these progressive conditions.

Restoration of Vision After Brain Injury Using Magnet Glasses

Visual impairments are common after traumatic brain injury (TBI) and negatively affect quality of life. We describe a 39-year-old woman with a severe TBI who was evaluated by the inpatient optometry and vision rehabilitation service with findings of complete right homonymous hemianopia and right cranial nerve III palsy with 30-degree right exotropia (eye turn out) and complete right ptosis (eyelid will not open). The 30-degree exotropia advantageously generated 30 degrees of right visual field expansion when the right ptosis was treated with a magnetic levator prosthesis, which restores eyelid opening. Once opened, the patient used visual field expansion derived from a right exotropia to overcome functional impairments caused by right hemianopia. Field expansion improved the patient's wheelchair mobility and reaching tasks during inpatient therapy. This is the first report of visual field expansion by strabismus facilitated by correction of ptosis. Strabismus should be considered for its potential field expansion benefits when homonymous visual deficits are present, before considering patching. A multidisciplinary vision rehabilitation team is well suited to make this determination.

Functional visual fields: relationship of visual field areas to self-reported function

PURPOSE

The aim of this study is to relate areas of the visual field to functional difficulties to inform the development of a binocular visual field assessment that can reflect the functional consequences of visual field loss.

METHODS

Fifty-two participants with peripheral visual field loss undertook binocular assessment of visual fields using the 30-2 and 60-4 SITA Fast programs on the Humphrey Field Analyser, and mean thresholds were derived. Binocular visual acuity, contrast sensitivity and near reading performance were also determined. Self-reported overall and mobility function were assessed using the Dutch ICF Activity Inventory.

RESULTS

Greater visual field loss (0-60°) was associated with worse self-reported function both overall (R² = 0.50; p < 0.0001), and for mobility (R² = 0.64; p < 0.0001). Central (0-30°) and peripheral (30-60°) visual field areas were similarly related to mobility function (R² = 0.61, p < 0.0001 and R² = 0.63, p < 0.0001 respectively), although the peripheral (30-60°) visual field was the best predictor of mobility self-reported function in multiple regression analyses. Superior and inferior visual field areas related similarly to mobility function (R² = 0.56, p < 0.0001 and R² = 0.67, p < 0.0001 respectively). The inferior field was found to be the best predictor of mobility function in multiple regression analysis.

CONCLUSION

Mean threshold of the binocular visual field to 60° eccentricity is a good predictor of self-reported function overall, and particularly of mobility function. Both the central (0-30°) and peripheral (30-60°) mean threshold are good predictors of self-reported function, but the peripheral (30-0°) field is a slightly better predictor of mobility function, and should not be ignored when considering functional consequences of field loss. The inferior visual field is a slightly stronger predictor of perceived overall and mobility function than the superior field.

Driving with homonymous visual field loss: a review of the literature

Driving is an important rehabilitation goal for patients with homonymous field defects (HFDs); however, whether or not people with HFDs should be permitted to drive is not clear. Over the last 15 years, there has been a marked increase in the number of studies evaluating the effects of HFDs on driving performance. This review of the literature provides a much-needed summary for practitioners and researchers, addressing the following topics: regulations pertaining to driving with HFDs, self-reported driving difficulties, pass rates in on-road tests, the effects of HFDs on lane position and steering stability, the effects of HFDs on scanning and detection of potential hazards, screening for potential fitness to drive, evaluating practical fitness to drive and the efficacy of interventions to improve driving of persons with HFDs. Although there is clear evidence from on-road studies that some people with HFDs may be rated as safe to drive, others are reported to have significant deficits in skills important for safe driving, including taking a lane position too close to one side of the travel lane, unstable steering and inadequate viewing (scanning) behaviour. Driving simulator studies have provided strong evidence of a wide range in compensatory scanning abilities and detection performance, despite similar amounts of visual field loss. Conventional measurements of visual field extent (in which eye movements are not permitted) do not measure such compensatory abilities and are not predictive of on-road driving performance. Thus, there is a need to develop better tests to screen people with HFDs for visual fitness to drive. We are not yet at a point where we can predict which HFD patient is likely to be a safe driver. Therefore, it seems only fair to provide an opportunity for individualised assessments of practical fitness to drive either on the road and/or in a driving simulator.

Difficulties in Daily Life Reported by Patients With Homonymous Visual Field Defects

BACKGROUND

Homonymous visual field defects (HVFD) are common after postchiasmatic acquired brain injury and may have a significant impact on independent living and participation in society. Vision-related difficulties experienced in daily life are usually assessed using questionnaires. The current study 1) links the content of 3 of these questionnaires to the International Classification of Functioning, Disability and Health (ICF) and 2) provides analyses of vision-related difficulties reported by patients with HVFD and minimal comorbidities.

METHODS

Fifty-four patients with homonymous hemianopia or quadrantanopia were asked about difficulties experienced in daily life because of their HVFD. This was performed during a structured interview including 3 standardized questionnaires: National Eye Institute Visual Functioning Questionnaire, Independent Mobility Questionnaire, and Cerebral Visual Disorders Questionnaire. The reported difficulties were linked to the ICF according to the ICF linking rules. Main outcome measures were presence or absence of experienced difficulties.

RESULTS

The ICF linking procedure resulted in a classification table that can be used in future studies of vision-related difficulties. Besides well-known difficulties related to reading, orientation, and mobility, a high proportion of patients with HVFD reported problems that previously have not been documented in the literature, such as impaired light sensitivity, color vision, and perception of depth.

CONCLUSIONS

A systematic inventory of difficulties experienced in daily life by patients with HVFD was performed using the ICF. These findings have implications for future study, assessment and rehabilitation of patients with HVFD.

Patient reported outcome measures for visual impairment after stroke: a systematic review

Purpose

The aim of this review was to identify patient reported outcome measures (PROMs) for use in research and clinical practice involving individuals with visual impairment following stroke and to evaluate their content validity against quality assessment criteria.

Method

A systematic review of the literature was conducted to identify articles related to the development and/or validation of PROMS. We searched scholarly online resources and hand searched journals. Search terms included MESH terms and alternatives relating to PROMs, visual impairments and quality of life. Data were extracted relating to the development and validation of the included instruments. The quality of the development process was assessed using a modified version of a PROM quality assessment tool.

Results

A total of 142 PROMs were identified, 34 vision-specific PROMs were relevant and available to be analysed in this review. Quality appraisal identified four highly rated instruments: the National Eye Institute Visual Functional Questionnaire (NEI-VFQ), Activity Inventory (AI), Daily Living Tasks Dependant on Vision (DLTV) and Veterans Affairs Low Visual Function Questionnaire (VA LV VFQ). The four instruments have only been used with either a limited number of stroke survivors or a sub-population within visual impairment following stroke.

Conclusion

No instruments were identified which specifically targeted individuals with visual impairment following stroke. Further research is required to identify the items which a population of stroke survivors with visual impairment consider to be of most importance. The validation of a combination of instruments or a new instrument for use with this population is required.

Electronic supplementary material

The online version of this article (doi:10.1186/s12955-015-0338-x) contains supplementary material, which is available to authorized users.

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.

Peripheral prism glasses: effects of moving and stationary backgrounds

PURPOSE

Unilateral peripheral prisms for homonymous hemianopia (HH) expand the visual field through peripheral binocular visual confusion, a stimulus for binocular rivalry that could lead to reduced predominance and partial suppression of the prism image, thereby limiting device functionality. Using natural-scene images and motion videos, we evaluated whether detection was reduced in binocular compared with monocular viewing.

METHODS

Detection rates of nine participants with HH or quadranopia and normal binocularity wearing peripheral prisms were determined for static checkerboard perimetry targets briefly presented in the prism expansion area and the seeing hemifield. Perimetry was conducted under monocular and binocular viewing with targets presented over videos of real-world driving scenes and still frame images derived from those videos.

RESULTS

With unilateral prisms, detection rates in the prism expansion area were significantly lower in binocular than in monocular (prism eye) viewing on the motion background (medians, 13 and 58%, respectively, p = 0.008) but not the still frame background (medians, 63 and 68%, p = 0.123). When the stimulus for binocular rivalry was reduced by fitting prisms bilaterally in one HH and one normally sighted subject with simulated HH, prism-area detection rates on the motion background were not significantly different (p > 0.6) in binocular and monocular viewing.

CONCLUSIONS

Conflicting binocular motion appears to be a stimulus for reduced predominance of the prism image in binocular viewing when using unilateral peripheral prisms. However, the effect was only found for relatively small targets. Further testing is needed to determine the extent to which this phenomenon might affect the functionality of unilateral peripheral prisms in more real-world situations.

Homonymous Visual Field Loss and Its Impact on Visual Exploration: A Supermarket Study

PURPOSE

Homonymous visual field defects (HVFDs) may critically interfere with quality of life. The aim of this study was to assess the impact of HVFDs on a supermarket search task and to investigate the influence of visual search on task performance.

METHODS

Ten patients with HVFDs (four with a right-sided [HR] and six with a left-sided defect [HL]), and 10 healthy-sighted, sex-, and age-matched control subjects were asked to collect 20 products placed on two supermarket shelves as quickly as possible. Task performance was rated as "passed" or "failed" with regard to the time per correctly collected item (T_C -failed = 4.84 seconds based on the performance of healthy subjects). Eye movements were analyzed regarding the horizontal gaze activity, glance frequency, and glance proportion for different VF areas.

RESULTS

Seven of 10 HVFD patients (three HR, four HL) passed the supermarket search task. Patients who passed needed significantly less time per correctly collected item and looked more frequently toward the VFD area than patients who failed. HL patients who passed the test showed a higher percentage of glances beyond the 60° VF (P < 0.05).

CONCLUSION

A considerable number of HVFD patients performed successfully and could compensate for the HVFD by shifting the gaze toward the peripheral VF and the VFD area.

TRANSLATIONAL RELEVANCE

These findings provide new insights on gaze adaptations in patients with HVFDs during activities of daily living and will enhance the design and development of realistic examination tools for use in the clinical setting to improve daily functioning. (http://www.clinicaltrials.gov, NCT01372319, NCT01372332).

Optical functional performance of the osteo-odonto-keratoprosthesis

PURPOSE

The aim of this study was to evaluate optical and visual functional performance of the osteo-odonto-keratoprosthesis (OOKP).

METHODS

Optical design and analysis was performed with customized optical design software. Nine patients with implanted OOKP devices and 9 age-matched control patients were assessed. Contrast sensitivity was assessed and glare effect was measured with a brightness acuity test. All OOKP patients underwent kinetic Goldmann perimetry and wavefront aberrometry and completed the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25).

RESULTS

Optical analysis showed that the optical cylinder is near diffraction-limited. A reduction in median visual acuity (VA) with increasing glare settings was observed from 0.04 logMAR (without glare) to 0.20 logMAR (with glare at "high" setting) and significantly reduced statistically when compared with the control group at all levels of glare (P < 0.05). Contrast sensitivity was significantly reduced when compared with age-matched controls at medium and high spatial frequencies (P < 0.05). Median Goldmann perimetry was 65 degrees (interquartile range, 64-74 degrees; V-4e isopters) and 69 degrees excluding 2 glaucomatous subjects. Several vision-related NEI VFQ-25 subscales correlated significantly with VA at various brightness acuity test levels and contrast sensitivity at medium spatial frequencies, including dependency, general vision, near activities and distance activities.

CONCLUSIONS

The OOKP optical cylinder provides patients with a good level of VA that is significantly reduced by glare. We have shown in vivo that updates to the optical cylinder design have improved the patient's field of view. Reduction of glare and refinement of cylinder alignment methods may further improve visual function and patient satisfaction.

Spontaneous recovery and treatment effects in patients with homonymous visual field defects: a meta-analysis of existing literature in terms of the ICF framework

Homonymous visual field defects (HVFDs) are a common consequence of posterior brain injury. Most patients do not recover spontaneously and require rehabiliation. To determine whether a certain intervention may help an individual patient, it is necessary to predict the patient's level of functioning and the effect of specific training. We provide an overview of both the existing literature on HVFDs in terms of the International Classification of Functioning, Disability, and Health (ICF) components and the variables predicting the functioning of HVFD patients or the effect of treatment. We systematically analyzed 221 publications on HVFD. All variables included in these articles were classified according to the ICF, as developed by the World Health Organization, and checked for their predictive value. We found that ICF helps to clarify the scope of the existing literature and provides a framework for designing future studies, which should consider including more outcome measures related to Activities and Participation. Although several factors have been described that predict HVFD patients' level of functioning or the effects of training, additional research is necessary to identify more.

A pilot evaluation of on-road detection performance by drivers with hemianopia using oblique peripheral prisms

Aims. Homonymous hemianopia (HH), a severe visual consequence of stroke, causes difficulties in detecting obstacles on the nonseeing (blind) side. We conducted a pilot study to evaluate the effects of oblique peripheral prisms, a novel development in optical treatments for HH, on detection of unexpected hazards when driving. Methods. Twelve people with complete HH (median 49 years, range 29-68) completed road tests with sham oblique prism glasses (SP) and real oblique prism glasses (RP). A masked evaluator rated driving performance along the 25 km routes on busy streets in Ghent, Belgium. Results. The proportion of satisfactory responses to unexpected hazards on the blind side was higher in the RP than the SP drive (80% versus 30%; P = 0.001), but similar for unexpected hazards on the seeing side. Conclusions. These pilot data suggest that oblique peripheral prisms may improve responses of people with HH to blindside hazards when driving and provide the basis for a future, larger-sample clinical trial. Testing responses to unexpected hazards in areas of heavy vehicle and pedestrian traffic appears promising as a real-world outcome measure for future evaluations of HH rehabilitation interventions aimed at improving detection when driving.

Are vision-specific quality of life questionnaires important in assessing rehabilitation for patients with hemianopia post stroke?

OBJECTIVE

To explore the relationship between disability and functional measures with vision-specific quality of life (QoL) measures for people with hemianopia and stroke.

METHOD

The Behavioral Inattention Test (BIT) and the Mayo-Portland Adaptability Inventory (MPAI) were compared with scores on 2 vision-specific QoL measures, the National Eye Institute Visual Function Questionnaire (NEI VFQ-25) and Veteran Low Vision Visual Function Questionnaire (VA LV VFQ-48).

SETTING

Rehabilitation hospitals in Adelaide, South Australia.

PARTICIPANTS

Stroke patients (n = 24) with homonymous hemianopia.

RESULTS

Most of the BIT and MPAI scores were significantly associated with the NEI VFQ-25 and VA LV VFQ-48 scores. Behavioral test scores of the BIT and the MPAI total score correlated with more aspects of the QoL measures than the other components of the BIT and the MPAI.

CONCLUSION

BIT and MPAI measure constructs associated with QoL for people with hemianopia following stroke. Vision-specific QoL questionnaires can complement the functional instruments by identifying the domains of difficulty, based on the instrument's subscale, that can guide rehabilitation therapists to address the person's deficit.

Prism therapy and visual rehabilitation in homonymous visual field loss

PURPOSE

Homonymous visual field defects (HVFD) are common and frequently occur after cerebrovascular accidents. They significantly impair visual function and cause disability particularly with regard to visual exploration. The purpose of this study was to assess a novel interventional treatment of monocular prism therapy on visual functioning in patients with HVFD of varied etiology using vision targeted, health-related quality of life (QOL) questionnaires. Our secondary aim was to confirm monocular and binocular visual field expansion pre- and posttreatment.

METHODS

Twelve patients with acquired, documented HVFD were eligible to be included. All patients underwent specific vision-targeted, health-related QOL questionnaire and monocular and binocular Goldmann perimetry before commencing prism therapy. Patients were fitted with monocular prisms on the side of the HVFD with the base-in the direction of the field defect creating a peripheral optical exotropia and field expansion. After the treatment period, QOL questionnaires and perimetry were repeated.

RESULTS

Twelve patients were included in the treatment group, 10 of whom were included in data analysis. Overall, there was significant improvement within multiple vision-related, QOL functioning parameters, specifically within the domains of general health (p < 0.01), general vision (p < 0.05), distance vision (p < 0.01), peripheral vision (p < 0.05), role difficulties (p < 0.05), dependency (p < 0.05), and social functioning (p < 0.05). Visual field expansion was shown when measured monocularly and binocularly during the study period in comparison with pretreatment baselines.

CONCLUSIONS

Patients with HVFD demonstrate decreased QOL. Monocular sector prisms can improve the QOL and expand the visual field in these patients.