Botulinum toxin for the treatment of strabismus.

BACKGROUND: The use of botulinum toxin as an investigative and treatment modality for strabismus is well reported in the medical literature. However, it is unclear how effective it is in comparison with other treatment options for strabismus. OBJECTIVES: The primary objective was to examine the efficacy of botulinum toxin therapy in the treatment of strabismus compared with alternative conservative or surgical treatment options. This review sought to ascertain those types of strabismus that particularly benefit from the use of botulinum toxin as a treatment option (such as small angle strabismus or strabismus with binocular potential, i.e. the potential to use both eyes together as a pair). The secondary objectives were to investigate the dose effect and complication rates associated with botulinum toxin. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, LILACS and three trials registers on 6 July 2022, together with reference checking to identify additional studies. We did not use any date or language restrictions in the electronic searches for trials. SELECTION CRITERIA: We planned to include randomized controlled trials (RCTs) comparing botulinum toxin with strabismus surgery, botulinum toxin alternatives (i.e. bupivacaine) and conservative therapy such as orthoptic exercises, prisms, or lens therapy for people of any age with strabismus. All relevant RCTs identified in this update compared botulinum toxin with strabismus surgery. DATA COLLECTION AND ANALYSIS: We used standard methods expected by Cochrane and assessed the certainty of the body of evidence using GRADE. MAIN RESULTS: We included four RCTs with 242 participants that enrolled adults with esotropia or exotropia, children with acquired esotropia, and children with infantile esotropia. The follow-up period ranged from six to 36 months. Two studies were conducted in Spain, and one each in Canada and South Africa. We judged the included studies to have a mixture of low, unclear and high risk of bias. We did not consider any of the included studies to be at low risk of bias for all domains. All four studies reported the proportion of participants who improved or corrected strabismus, defined as ≤ 10 prism diopters (PD) at six months (two studies) or ≤ 8 PD at one year (two studies). Low-certainty evidence suggested that participants treated with the surgery may be more likely to improve or correct strabismus compared with those who treated with botulinum toxin (risk ratio (RR) 0.72, 95% confidence interval (CI) 0.53 to 0.99; I² = 50%; 4 studies, 242 participants; low-certainty evidence). One study, which enrolled 110 children with infantile esotropia, suggested that surgery may reduce the incidence of additional surgical intervention required, but the evidence was very uncertain (RR 3.05, 95% CI 1.34 to 6.91; 1 study, 101 participants; very low-certainty evidence). Two studies conducted in Spain compared botulinum toxin with surgery in children who required retreatment for acquired or infantile esotropia. These two studies provided low-certainty evidence that botulinum toxin may have little to no effect on achieving sensory fusion (RR 0.88, 95% CI 0.63 to 1.23; I² = 0%; 2 studies, 102 participants) and stereopsis (RR 0.86, 95% CI 0.59 to 1.25; I² = 0%; 2 studies, 102 participants) compared with surgery. Three studies reported non-serious adverse events. Partial transient ptosis (range 16.7% to 37.0%) and transient vertical deviation (range 5.6% to 18.5%) were observed among participants treated with botulinum toxin in three studies. In one study, 44.7% participants in the surgery group experienced discomfort. No studies reported serious adverse events or postintervention quality of life. AUTHORS' CONCLUSIONS: It remains unclear whether botulinum toxin may be an alternative to strabismus surgery as an independent treatment modality among certain types of strabismus because we found only low and very low-certainty evidence in this review update. Low-certainty evidence suggests that strabismus surgery may be preferable to botulinum toxin injection to improve or correct strabismus when types of strabismus and different age groups are combined. We found low-certainty evidence suggesting botulinum toxin may have little to no effect on achievement of binocular single vision compared with surgery in children with acquired or infantile esotropia. We did not find sufficient evidence to draw any meaningful conclusions with respect to need for additional surgery, quality of life, and serious adverse events. We identified three ongoing trials comparing botulinum toxin with conventional surgeries in the varying types of strabismus, whose results will provide relevant evidence for our stated objectives. Future trials should be rigorously designed, and investigators should analyze outcome data appropriately and report adequate information to provide evidence of high certainty. Quality of life and cost-effectiveness should be examined in addition to clinical and safety outcomes.

UK exceptional case driving application outcomes in post-stroke homonymous hemianopia: results from a clinical study.

PURPOSE: We report results in relation to returning to driving in the UK under the exceptional cases rule for visual field loss. METHODS: The Hemianopia Adaptation Study is a prospective clinical study recruiting adult stroke survivors with new onset homonymous hemianopia. The mobility assessment course (MAC) was used to measure navigational scanning. Car drivers were offered a 1-year post-stroke assessment to consider referral for driving assessment. RESULTS: Of 144 participants, 51 were eligible for driving assessment, with 13 (25.4%) accepting appointment for UK Driving and Vehicle Licensing Agency (DVLA) referral. A statistically significant difference in gender and baseline Barthel (stroke severity) scores was found between those requesting referral and those declining (p = 0.046; p < 0.001). MAC outcomes were significantly different, with those referred having a lower percentage of target omissions (9.0%) and faster mean course completion time (46.0 s), than those not referred (28.3%/72.5 s) (p = 0.006/p < 0.001). Twelve of the 13 referred were offered a driving assessment by the DVLA. All 12 passed and returned to driving. CONCLUSIONS: It is possible for individuals with post-stroke homonymous hemianopia to return to driving, where exceptional cases criteria are met. There is evidence to support use of the MAC as a clinical measurement of adaptation.IMPLICATIONS FOR REHABILITATIONIndividuals with post-stroke homonymous hemianopia should be fully informed regarding driving regulations that can differ between countries and sometimes different states within a country, as well as provided with the support and opportunity to consider a return to driving if appropriate.Professionals providing care within the stroke multi-disciplinary team should be aware that it is possible for patients with homonymous hemianopia to return to driving, when exceptional cases criteria are met.The mobility assessment course (MAC) should be considered as a clinical measurement of adaptation in homonymous hemianopia.A cut-off score of ≤25% omissions on MAC could be employed to determine those likely to adapt to hemianopia long-term and potentially return to driving.

National application of the European visual field standards for driving: a survey study.

Aims: To provide an overview of how the European visual field standards for driving (specified in Commission Directive 2009/113/EC) are applied and determine whether individuals with visual field defects are treated equally across Europe. Methods: One ophthalmic expert from each of 32 European countries was invited to participate in an electronic survey. They were presented with threshold and Esterman perimetry results of 15 cases of visual field defects and asked to classify each case as either passed or failed in reference to their national standards. The results were compared with the European Driving Test Group 1 (EDT1), which is a new perimetry algorithm that adheres to the recommendations by the Eyesight Working Group. Fleiss' kappa was used to determine the inter-rater agreement. Results: Twenty-five countries responded. Three of 15 cases were passed by all. Full agreement on a failed case was not reached. Denmark graded most leniently and passed 12 cases. Bulgaria, Romania and Slovakia graded most strictly and passed five cases. The Fleiss' kappa score was 0.52 (95% CI 0.49 to 0.55). Only Slovenia was in full agreement with the EDT1. Fifteen countries endorsed specific perimetric tests for assessing fitness to drive. Five of these also defined pass/fail criteria. Conclusion: The directive fails to establish a uniform approach to the visual field requirements, as evident by moderate pass/fail agreement between the national experts. Because the visual standards for driving are enforced differently, identical visual field loss can result in either revocation or approval of a driving license.

Development of core outcome sets and core outcome measures for central visual impairment, visual field loss and ocular motility disorders due to stroke: a Delphi and consensus study.

OBJECTIVES: Reporting of research for stroke-related visual impairment is inconsistent. The aim of this study was to define three core outcome sets (COS) and related core outcome measurements (COM) for central visual impairment, visual field loss and ocular motility disorders in stroke research. DESIGN: The consensus process consisted of an online three-round Delphi survey followed by a consensus meeting of key stakeholders. SETTING: UK-wide survey. PARTICIPANTS: Stakeholders included orthoptists, occupational therapists, ophthalmologists, stroke survivors and COS users such as researchers, journal editors and guideline developers. OUTCOME MEASURES: For COS development, a list of potentially relevant visual outcomes was created after review of the literature and further grouped into outcome domains. For COM development, a list of potential instruments was created after review of the literature and quality appraised for reliability and validity. RESULTS: COS-119 potential outcomes extracted from published literature. Similar assessment outcomes were grouped into 24 outcome domains. Delphi process included 123 participants in round 1, 65 round 2, 51 round 3. Twelve participants attended the consensus meeting with recommended outcome domains for central visual impairment (visual acuity, functional vision, quality of life), visual field loss (visual fields, functional vision, quality of life) and ocular motility disorders (eye alignment, eye movements, functional vision, quality of life). COM-52 test options extracted from the COS outcomes and grouped into 16 domains. Thirteen participants attended the COM consensus meeting. Recommended instruments for measurement of these outcomes include; Logarithm of the Minimal Angle of Resolution visual acuity, cover test, cardinal position eye movement assessments, peripheral visual field perimetry, Visual Function Questionnaire-25. CONCLUSIONS: COS and COM are defined for vision research for stroke survivors. Their use has potential to reduce heterogeneity in routine clinical practice and improve standardisation and accuracy of vision assessment. Future research is required to evaluate the use of these COS and COM.

Audio-visual stimulation for visual compensatory functions in stroke survivors with visual field defect: a systematic review.

BACKGROUND: Hemianopia is a complete or partial blindness in the visual fields of both eyes, commonly caused by cerebral infarction. It has been hypothesized that systematic audio-visual (AV) stimulation of the blind hemifield can improve accuracy and search times, probably due to the stimulation of bimodal representations in the superior colliculus (SC), an important multisensory structure involved in both the initiation and execution of saccades. METHODS: A narrative synthesis of the findings is presented to highlight how AV rehabilitation impacts on patients with hemianopia including visual oculomotor function, functional ability in activities of daily living, hemianopic dyslexia, visual scanning and searching tasks, maintaining of functional ability post training and the effect on brain multisensory integration by using neuroimaging. RESULTS: Sixteen studies were included (fourteen articles (188 participants) and two literature reviews). Results were grouped into AV training of hemianopia in adults and in children and then further grouped according to the AV task type: tasks measuring the training effects by comparing visual stimulation training to audio-visual training, localization abilities in homonymous hemianopia (HH) and AV integration in patients with HH. CONCLUSION: Systematic AV training may improve the processing of visual information by recruiting subcortical pathways, and because most of the patients with visual cortex damage have an intact SC, it might be useful to use the bimodal AV training to activate retinotectal functions. Nevertheless, the underlying mechanisms supporting the reported positive effects are not currently understood. Systematic functional and/or structural imaging studies may help in understanding the underlying mechanism and inform the design of optimal training paradigms.

Adaptation to post-stroke homonymous hemianopia - a prospective longitudinal cohort study to identify predictive factors of the adaptation process.

PURPOSE: To determine any factors that predict how an individual will adapt to post-stroke hemianopic visual field loss, with close monitoring of the adaptation process from an early stage. MATERIALS AND METHODS: The Hemianopia Adaptation Study (HAST) is a prospective observational longitudinal cohort clinical study. Adult stroke survivors (n = 144) with new onset homonymous hemianopia were monitored using standardised mobility assessment course (MAC) as the primary outcome measure of adaptation. RESULTS: Several baseline variables were found to be good predictors of adaptation. Three variables were associated with adaptation status at 12-weeks post-stroke: inferior % visual field, % total MAC omissions, and MAC completion time (seconds). Baseline measurements of these variables can predict the adaptation at 12 weeks with moderate to high accuracy (area under ROC curve, 0.82, 95% CI 0.74-0.90). A cut-off score of ≤25% target omissions is suggested to predict which individuals are likely to adapt by 12-weeks post-stroke following gold standard care. CONCLUSIONS: Adaptation to hemianopia is a personal journey with several factors being important for prediction of its presence, including MAC outcomes and extent of inferior visual field loss. A clinical recommendation is made for inclusion of the MAC as part of a functional assessment for hemianopia.Implications for rehabilitationThe mobility assessment course (MAC) should be considered as an assessment of mobility/scanning in the rehabilitation of patients with homonymous hemianopia.A cut-off score of ≤25% omissions on MAC could be employed to determine those likely to adapt to hemianopia long-term.Targeted support and therapy for patients with significant visual loss in the inferior visual field area should be considered.

Impact of visual impairment following stroke (IVIS study): a prospective clinical profile of central and peripheral visual deficits, eye movement abnormalities and visual perceptual deficits.

AIM: This study evaluates the spectrum of visual impairment in stroke survivors. METHODS: The Impact of Visual Impairment after Stroke (IVIS) study is a multi-centre, acute stroke unit, prospective epidemiology study. Comprehensive visual examination was offered to all stroke survivors. RESULTS: 1500 stroke admissions were recruited. 1204 stroke survivors had visual assessment. Reduced central vision was documented in 529, visual field loss in 308, ocular motility abnormalities in 533 stroke survivors, visual perception deficits in 59 stroke survivors and visual inattention in 315 stroke survivors. About half, regardless of visual impairment type, were visually asymptomatic. Recovery, whether full or partial, was best for central vision, ocular motility abnormalities and visual perception deficits (about 70% improvement) occurring over a mean follow-up period of 2-3 months. CONCLUSIONS: Incidence of impaired central vision, visual field loss, ocular motility disorders and visual inattention was 29.4%, 24.8%, 39.3% and 26.2% respectively. Visual impairment was more likely to occur in more severe stroke and older stroke survivors. Asymptomatic cases raise concerns for acute stroke units where robust specialist vision screening is not routine. Those with partial/no recovery require specialist follow-up and management whilst the wide range of abnormalities highlight the need for specialist visual assessment acutely.Implications for rehabilitationVisual impairment is a common consequence of stroke.Incidence of visual impairment is about 60%.Significant numbers of stroke survivors are visually asymptomatic, highlighting the need for standardised vision assessments.Many stroke survivors have persistent long-term visual impairment, necessitating referral and access to specialist eye care services.

Developing a stroke-vision care pathway: a consensus study.

PURPOSE: We aimed to develop a stroke-vision care pathway for stroke survivors with visual impairment. METHODS: A literature review searched key electronic bibliographic databases for care pathways related to stroke/vision. Two focus group meetings using semi-structured/nominal group technique reached consensus on items relevant for inclusion in a stroke-vision care pathway. Following the development of the pathway, we obtained feedback through consultation with patient and professional groups. RESULTS: The literature review identified two care pathways relevant to acute stroke and generic vision disorders. Outputs from focus groups related to how stroke survivors present with vision problems; the time points at which stroke survivors present with vision symptoms; the relevance of different types of visual condition to different vision services; the importance of support services supplementary to hospital services and; the importance of key resources to promote awareness of vision problems in stroke survivors. Refinement of the pathway considered time duration from stroke onset, reporting of symptoms to services, and signposting/referrals required dependent on visual condition type. CONCLUSIONS: This new stroke-vision care pathway is a process pathway describing potential options for stroke survivors with visual impairment to access health care and obtain appropriate referral(s) to vision services relevant to their specific vision problem(s).IMPLICATIONS FOR REHABILITATIONVisual impairment is a common consequence of stroke.It is imperative that those who care for stroke survivors are aware of the visual consequences of stroke and make the appropriate referrals for vision and support services.The stroke-vision care pathway is a process pathway that describes the potential options for stroke survivors with visual impairment to access health care and obtain the appropriate referral(s) to vision services relevant to their specific vision problem(s).The stroke-vision care pathway is available (free to download) from the VISION research unit (www.vision-research.co.uk) website and available as supplemental information with this publication.

Orthoptic service survey in the UK and Ireland during the interim recovery period (summer 2020) of the COVID-19 pandemic.

COVID-19 extended through 2020 with impact on all hospital services. The purpose of this study was to determine the extent of orthoptic service provision during the initial recovery period from July to September 2020 in the UK, Ireland and Channel Islands. We conducted a prospective survey-based cross-sectional study using an online survey aiming for coverage of orthoptic departments across the UK, Ireland and Channel Islands. The survey sought to gather data on orthoptic practice during the COVID-19 pandemic period between the first and second waves in the UK. Questions included within the survey asked about the impact on services paused or reduced during the pandemic, the reinstatement of services, backlog of appointments, changes to arrangement and conduct of appointments, changes to working practice, impact to lives of orthoptists, and access by orthoptists to professional support and guidelines. We circulated the online survey through the British and Irish Orthoptic Society that reaches over 95% of UK and Irish orthoptic services and through social media and orthoptic research networks. This survey was open from July 1st to September 30th 2020 and achieved a response rate from orthoptic departments of 85%. A high rate (92%) of teleconsultations continued with 50% of departments using a proforma to guide the teleconsultation and with added use of risk assessment for patient appointments. To enable reopening of clinics, multiple changes were made for patient and staff flow through clinic areas. Reduced clinical capacity was confirmed by 76.5% of departments. Appointments averaged 15-20 minutes and there was routine use of PPE and cleaning and adoption of staggered appointments with added evening/weekend clinics. There was increased use of information resources/leaflets for patients and dependence on professional and health care guidance documents. The average backlog for patient appointments had increased to 26 weeks. The initial UK and Irish recovery phase in summer 2020 allowed a glimpse at adjustments needed to reopen orthoptic clinics for in-person appointments. Teleconsultation remained in frequent use but with greater risk assessment and triage to identify those requiring in-person appointments.

Standard automated perimetry using size III and size V stimuli in advanced stage glaucoma: an observational cross-sectional comparative study.

OBJECTIVES: In this study, we sought to evaluate the extent of further visual field that could be assessed when using stimulus size V in standard automated perimetry compared with size III in advanced stage glaucoma and whether cut-off values could be determined for when to switch from size III to size V. DESIGN: Prospective cross-sectional study. SETTING: Single-centre outpatient eye clinic in India (New Delhi). PARTICIPANTS: Advanced stage glaucoma defined as stages 3-4. INTERVENTION: Central static perimetry with Octopus 900 G programme (size III stimulus dynamic strategy) and low vision central programme (size V stimulus dynamic strategy). PRIMARY AND SECONDARY OUTCOME MEASURES: Visual field assessment for right and left eyes with both sizes III and V were undertaken within one clinic visit. RESULTS: We recruited 126 patients (170 eyes). Mean patient age at assessment was 55.86 years (SD 15.15). Means (SD) for size III versus size V, respectively, were 6.94 dB (5.58) and 12.98 dB (7.77) for mean sensitivity, 20.02 dB (5.67) and 19.22 dB (7.74) for mean deviation, 5.89 dB (2.29) and 7.69 dB (2.78) for standard loss variance and 3.32 min (1.07) and 6.40 min (1.43) for test duration. All except mean deviation were significantly different between size III and V tests. CONCLUSION: Useful visual field information was obtained with size V stimuli which allowed continued monitoring of these patients that was not possible with size III. Increased test duration, standard loss variance and mean sensitivity were found with size V, as expected, given that more visual responses were obtained with the increased target size. A switch from size III to V may be considered when mean sensitivity reaches 10 dB and/or mean deviation reaches 18 dB.

The Impact of Visual Impairment in Stroke (IVIS) Study - Evidence of Reproducibility.

Reporting generalisable data across stroke populations is important. We aimed to evaluate the Impact of Visual Impairment after Stroke (IVIS) visual assessment protocol in a different UK geographical area. This was a single-centre acute stroke unit, prospective study (IVIS-extension (IVIS-e) study) with comparison to a multi-centre acute stroke cohort (IVIS study). Orthoptists reviewed all stroke survivors with a standardised assessment of visual acuity, visual fields, ocular alignment, ocular motility, visual inattention and visual perception including a standardised follow-up strategy. 123 stroke survivors underwent visual screening: 42% women, 58% men, mean age 63.6 years and 86% ischaemic strokes. Ethnicity consisted of 68.3% white British and 28.5% being Pakistani, Indian, Caribbean, Bangladeshi, Black and Chinese. Two died and 28 could not be assessed. Of the 93 remaining, 10 stroke survivors (10.8%) had a normal visual assessment and 83 (89.2%) had visual impairments detected. Fifty-seven stroke survivors were assessed at their first orthoptic visit within 3 days of stroke onset; the remainder being assessed at subsequent orthoptic visits to the stroke unit. The visual profile was similar across the IVIS-e and original IVIS cohorts for most types of visual impairment although, overall, more visual impairment was detected in IVIS-e. Differences between the cohorts were primarily related to lower age and smaller white British ethnicity in the IVIS-e cohort. This likely relates to the differing population demographics for the two cohort geographical areas. Further roll-out of the IVIS assessment protocol to other regions and countries would improve detection of post-stroke visual impairment.

Identifying priority review questions for Cochrane Eyes and Vision: protocol for a priority setting exercise.

INTRODUCTION: Cochrane Eyes and Vision (CEV) is an international network of individuals working to prepare, maintain and promote access to systematic reviews of interventions to treat, prevent or diagnose eye diseases or vision impairment. CEV plans to undertake a priority setting exercise to identify systematically research questions relevant to our scope, and to formally incorporate input from a wide range of stakeholders to set priorities for new and updated reviews. METHODS AND ANALYSIS: The scope of CEV is broad and our reviews include conditions that are common and have a high global disease burden, for example, cataract and dry eye disease, and conditions that are rare but have a high impact on quality of life and high individual cost such as eye cancer. We plan to focus on conditions prioritised by WHO during the development of the Package of Eye Care Interventions. These conditions were selected based on a combination of data on disease magnitude, healthcare use and expert opinion. We will identify priority review questions systematically by summarising relevant data on research in Eyes and Vision from a range of sources, and compiling a list of 10-15 potential review questions (new and/or updates) for each condition group. We will seek the views of external and internal stakeholders on this list by conducting an online survey. Equity will be a specific consideration. ETHICS AND DISSEMINATION: The study has been approved by the ethics committee of the London School of Hygiene & Tropical Medicine. We will disseminate the findings through Cochrane channels and prepare a summary of the work for publication in a peer-reviewed journal.

Core outcome set for three ophthalmic conditions: a healthcare professional and patient consensus on core outcome sets for amblyopia, ocular motility and strabismus (COSAMS Study).

OBJECTIVES: Amblyopia, strabismus and ocular motility disorders are common conditions with significant impact on visual function, appearance and quality of life. We aimed to establish a core set of outcomes for each of the three conditions for use in clinical trials and routine clinical practice. DESIGN: A comprehensive databank of outcomes was developed from a systematic review of the literature and a series of focus groups with healthcare professionals, researchers, patients and carers. The databank of outcomes was scored in a two-round Delphi Survey completed by two stakeholder groups: healthcare professionals/researchers and patients/carers. Results of the online Delphi were discussed at a face-to-face consensus meeting where the core outcome sets were finalised. SETTING: UK-wide consultation. PARTICIPANTS: Researchers, clinicians, patients and carers. OUTCOME MEASURES: Core outcome sets. RESULTS: For amblyopia, strabismus and ocular motility, 40/42/33 participants contributed to both rounds of the Delphi; six/nine/seven members attended consensus meetings, respectively. Consensus was reached on ten core outcomes for both amblyopia and ocular motility and nine for strabismus. All three conditions shared the core outcomes: adverse events, cost, vision-related quality of life and ocular alignment. The strabismus and ocular motility disorder core sets included, in addition, measuring the deviation, binocular vision, ocular movement, patient satisfaction and symptoms. The amblyopia set, distinct from the sets for the other two conditions, included best corrected distance and near visual acuity, spherical and cylindrical refraction, compliance and treatment-related and functionality/long-term impacts. CONCLUSIONS: The study used robust consensus methods to develop a core outcome set for three ophthalmic conditions. Implementation of these core outcome sets in clinical trials and routine clinical practice will ensure that the outcomes being measured and reported are relevant to all stakeholders. This will enhance the relevance of study findings and enable comparison of results from different studies.

"Eye" Don't See: An Analysis of Visual Symptom Reporting by Stroke Survivors from a Large Epidemiology Study.

AIM: The purpose was to explore the reported symptoms of post-stroke visual impairment from a large multi-centre prospective epidemiology study. METHODS: Visual assessment, including a case history, visual acuity, ocular alignment, ocular motility, visual fields, visual inattention and visual perception, was attempted for all stroke admissions to three acute stroke units. RESULTS: Of 1500 stroke admissions, 1204 received a visual assessment, of which 867 had one or more visual impairments. Of those identified with visual impairment 44.4% reported visual symptoms. The most common visual symptoms were blurred/altered vision (22.1%), field loss (12.6%), diplopia (9.9%) and reading difficulties (9.7%). 703 were identified to have a new visual impairment, 47.1% reported visual symptoms. No visual symptoms were reported by 38.4% and 14.5% were unable to report symptoms. Visual symptoms were first reported at a median of 3 days (IQR2-8) and mean of 16.0 days (SD39.8) from stroke onset. Those that reported symptoms were younger (p<0.001) and more independent (p<0.001) than those who were asymptomatic or unable to report. No significant difference was found between likelihood of reporting visual symptoms or not based on severity of reduced central vision, visual field loss or visual inattention. Stroke survivors with a manifest squint and cranial nerve palsies were significantly more likely to report symptoms. CONCLUSIONS: Almost 40% of stroke survivors with new onset visual impairment do not or cannot report visual symptoms. This highlights the importance of objective screening to ensure stroke survivors receive appropriate and timely referral to specialist services to access necessary treatment.

Biomechanical adaptation to post-stroke visual field loss: a systematic review.

BACKGROUND: Homonymous visual field defects represent the most frequent type of visual field loss after stroke, affecting nearly 30% of individuals with unilateral post-chiasmal brain damage. This review aimed to gather the available evidence on the biomechanical changes to visual field loss following stroke. METHODS: A systematic review was conducted inclusive of randomised controlled trials, cohort studies, before-after studies and case-controlled studies. Studies including adult and paediatric participants that investigated eye, head, or body movements in post-stroke visual field loss during visual exploration tasks were included. Search terms included a range of MESH terms as well as alternative terms relating to stroke, visual field loss, hemianopia, visual functions and scanning behaviour. Articles were selected by two authors independently. Data were extracted by one author and verified by a second. All included articles were assessed for risk of bias using checklists appropriate to the study design. RESULTS: Thirty-six articles (1123 participants) were included in the overall review (Kappa 0.863) and categorised into simulated or true visual field loss (typically hemianopia). Seven studies identified the biomechanical alterations to simulated hemianopia compared to normal performance. Twenty-nine studies detailed eye, head and body movement parameters in true hemianopia. Hemianopic participants and healthy adults with simulated hemianopia differed significantly from controls in various fixation and saccade parameters as indicated by increased number and duration of fixations, number and duration of saccades and scan path length with shorter mean saccadic amplitude. Under simulated hemianopia, participants were consistently biased towards the sighted visual field while gaze behaviour in true hemianopia was biased in the direction of the blind hemifield. CONCLUSIONS: There is considerable evidence on the altered eye movements that occur in true hemianopia and in healthy adults with simulated hemianopia. Successful performance in naturalistic tasks of visual exploration appears to be related to compensatory mechanisms of visual exploratory behaviour, namely, an increase in the amplitude and peak velocity of saccades, widening horizontally the distribution of eye movements, and a shift of the overall distribution of saccades into the blind field. This review highlights the lack of studies reporting head and other body movement parameters in hemianopia. Further studies with robust methodology and large sample sizes involving participants with post-stroke visual field loss are needed. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020194403.

Octopus 900 Automated Kinetic Perimetry versus Standard Automated Static Perimetry in Glaucoma Practice.

Purpose: The presence of central visual field loss does not infer the extent of peripheral visual field loss. In advanced stage glaucoma, we evaluated whether automated kinetic perimetry provided additional visual field information to that of central static perimetry. Materials and Methods: We undertook a prospective cross-sectional study of advanced-stage glaucoma defined as stages 3-4. Visual field assessment for right and left eyes was undertaken within one clinic visit using the Octopus 900 G programme and kinetic strategy. Results: We recruited 126 patients (170 eyes). Mean patient age at assessment was 55.86 years (SD 15.15). Mean kinetic reaction time was 1503.96 ms (SD 801.68). Kinetic I4e was plotted in 71% of eyes with an unadjusted area of 2513.68 degrees2 (SD 2397.91) and mean isopter radius of 23.16 degrees (SD 13.07). Kinetic I2e was plotted in 53.5% of eyes with an unadjusted area of 627.07 degrees2 (SD 1291.94) and mean isopter radius of 7.47 degrees (SD 10.59). Increased reaction time was associated with a poorer visual field (p = .001). Mean sensitivity, mean deviation and standard loss variance values on static perimetry were higher in patients who had a defined kinetic field boundary than in patients with no kinetic response to I4e stimulus (p = .0001). However, this corresponded to only small-to-medium correlation between static fields and existent kinetic fields: the presence of poor static fields did not always infer a poor kinetic visual field as poor static fields could also have good kinetic visual fields. Conclusions: Although we confirmed a lack of agreement and only a small to medium correlation between the extents of central versus peripheral visual field loss, automated kinetic perimetry did provide additional peripheral (outside the static 30-degree central field) visual field information which was clinically useful in the presence of non-informative severely defected central visual fields.

Stroke-Related Visual Impairment; is There an Association with Atrial Fibrillation?

BACKGROUND/OBJECTIVES: Stroke-related visual impairment and atrial fibrillation are both common following stroke. This study explores whether presence of visual impairment following stroke is associated with presence of atrial fibrillation (AF). SUBJECTS/METHODS: The Impact of Visual Impairment after Stroke (IVIS) study is a multi-centre, acute stroke unit, prospective epidemiology study. Standardised visual assessments included visual acuity, reading, visual fields, eye movements and visual perception. AF and blood pressure (BP) were measured on admission. Further data capture included stroke type, age, gender, stroke severity. Analysis included descriptive statistics, independent samples analysis and multivariate analysis for comparison of AF and visual impairment against covariates. RESULTS: 1500 stroke admissions were recruited of which 1204 stroke survivors had visual assessment. New onset stroke-related visual impairment (n = 703) was significantly associated with older age and stoke severity. AF and BP data were available for 889 stroke survivors. AF was present on admission for 258 stroke survivors and significantly associated with older age, stroke severity and discharge destination. A significant association was found for presence of AF and presence of visual impairment. However, stroke severity was a contributing factor for this association. High systolic BP (>140 mmHg) was present in 62% and high diastolic BP (>90 mmHg) in 29%, but not associated with presence of visual impairment. CONCLUSIONS: AF and visual impairment, independently, occur commonly in stroke. Although our results show an association between AF and visual impairment, this appears to be independently influenced by stroke severity. AF was not associated with type of visual impairment or extent of visual recovery. It remains unknown if AF causes more severe visual impairment.

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.