To provide a systematic overview of interventions for stroke related visual impairments.
Every year, nearly 800,000 Americans suffer a stroke, according to the Internet Stroke Center.
Strokes are a leading cause of death and disability, but what many people don’t realize is that two out of three stroke survivors will also experience visual impairments related to their stroke (Rowe). These can include diminished central or peripheral vision, eye movement abnormalities or visual perceptual defects.
Sadly, it is not uncommon for me to see patients who are still struggling with undiagnosed vision problems months or even years after a stroke. There are a number of reasons for this. In the immediate days and weeks after a stroke, patients and their families and doctors are often most concerned about preventing brain hemorrhages and addressing motor and language deficits. After that, patients may have difficulty articulating their symptoms or may not be aware that balance issues are connected to vision. In some cases, they may have been examined and incorrectly told that nothing can be done.
Given the prevalence of post-stroke visual impairment, anyone who suffers a stroke should be seen by an eye care specialist as soon as possible and, ideally, be referred to a neuro-optometric rehabilitation optometrist. Visual rehabilitation can lead to greater independence and improved quality of life and can accelerate the success of other therapies. In fact, most stroke survivors need more than one type of rehabilitation, so it is not unusual for me to work with a team of speech, occupational or physical therapists to help the stroke survivor learn new ways of performing tasks to circumvent or compensate for any residual disabilities.
The most common visual complication of stroke is a homonymous hemianopsia, or a visual field defect on the same side in each eye, resulting from damage to the occipital lobe, where the majority of visual processing takes place. This type of stroke-related field loss is often accompanied by a visual midline shift, which occurs when there is a mismatch between visual spatial information and the patient’s proprioceptive base of support.
A shift in the visual midline can directly affect posture, balance and spatial orientation, and it significantly increases the risk of falls. It is relatively easy to diagnose: Just ask a patient to walk down the hall and observe whether they drift to one side or tip backwards or forwards. In a study that I co-authored with Dr. William Padula, we showed that intervention with yoked prisms can restore the visual midline, thereby improving balance and reducing the risk of falls and subsequent injury.
Strokes that affect other parts of the brain may result in cranial nerve damage-associated diplopia or the rare but fascinating phenomenon of visual neglect, in which the patient completely loses awareness of one side of the body. In less severe cases, there can also be subtle effects on eye tracking and teaming, leading to impaired saccades and pursuits or convergence insufficiency. These impairments can be improved with vision rehabilitation and prism lenses.
Vision rehabilitation may not always be able to fully restore patients to the same degree of visual function they had before the stroke, but we can go a long way towards improving quality of life and helping patients maximize the vision they have.
Internet Stroke Center. U.S. Stroke Statistics. http://www.strokecenter.org/patients/about-stroke/stroke-statistics/. Accessed January 16, 2019.
Padula WV, et al. NeuroRehabilitation. 2015;doi:10.3233/NRE-151263.
Rowe FJ. Brain Behav. 2017;doi:10.1002/brb3.778.
A new University of Liverpool study, published in Wiley Brain and Behaviour, examines the factors that influence how a person adapts to visual field loss following stroke.
Approximately 65% of acute stroke survivors have visual impairment which typically relates to impaired central or peripheral vision, eye movement abnormalities, or visual perceptual defects.
Symptoms can include blurred or altered vision, double or jumbled vision, loss of visual field, reading difficulty, inability to recognize familiar objects or people and glare. The factors that influence how a person adapts to a Post stroke visual impairment (PSVI) is currently an under researched area.
Compensate and adapt
In order to profile the full range of influencing factors researchers from the University’s Department of Health Services Research, led by Dr Fiona Rowe, systematically reviewed data pertaining to PSVI produced between 1861 and 2016. This data included randomized controlled trials, controlled trials, cohort studies, observational studies, and case controlled studies.
The researchers identified 47 studies which involved a total of 2,900 participants and categorised them into two sections. Section one included seventeen studies where the reviewers were able to identify a factor they considered as likely to be important for the process of adaptation to post stroke visual field loss.
Section two included thirty studies detailing interventions for visual field loss that the reviewers deemed likely to have an influence on the adaptation process.
The study highlighted a substantial amount of evidence showing patients can be supported to compensate and adapt to visual field loss following stroke using a range of strategies and methods.
Valuable starting point
Dr Rowe, said: “This is an area that must be addressed in the interest of equality for those with visual impairment. It is vital that the factors important for adaptation be identified to allow clinicians to recognise which people are likely to have difficulty adapting and target interventions specifically within these areas, as well as to develop methods for assessing adaptation and monitoring change over time.
“Our review also highlights the fact that many unanswered questions remain: what does adaptation to visual field loss mean to the patient, carer, and clinician? How can adaptation be measured over time? Why do some people adapt more effectively and at a quicker rate than others, despite seemingly similar rehabilitation opportunities and experiences? If these questions can be answered through high quality observations and assessments then this would be a valuable starting point for understanding adaptation.”
Materials provided by University of Liverpool. Note: Content may be edited for style and length.
To provide a systematic overview of interventions for stroke related visual impairments.
A systematic review of the literature was conducted including randomized controlled trials, controlled trials, cohort studies, observational studies, systematic reviews, and retrospective medical note reviews. All languages were included and translation obtained. This review covers adult participants (aged 18 years or over) diagnosed with a visual impairment as a direct cause of a stroke. Studies which included mixed populations were included if over 50% of the participants had a diagnosis of stroke and were discussed separately. We searched scholarly online resources and hand searched articles and registers of published, unpublished, and ongoing trials. Search terms included a variety of MESH terms and alternatives in relation to stroke and visual conditions. Article selection was performed by two authors independently. Data were extracted by one author and verified by a second. The quality of the evidence and risk of bias was assessed using appropriate tools dependant on the type of article.
Forty-nine articles (4142 subjects) were included in the review, including an overview of four Cochrane systematic reviews. Interventions appraised included those for visual field loss, ocular motility deficits, reduced central vision, and visual perceptual deficits.
Further high quality randomized controlled trials are required to determine the effectiveness of interventions for treating post-stroke visual impairments. For interventions which are used in practice but do not yet have an evidence base in the literature, it is imperative that these treatments be addressed and evaluated in future studies.
Visual impairments following stroke may include abnormalities of central and/or peripheral vision, eye movements and a variety of visual perception problems such as inattention and agnosia. The visual problems (types of visual impairment) can be complex including ocular as well as cortical damage (Jones & Shinton, 2006; Rowe et al., 2009a). Visual impairments can have wide reaching implications on daily living, independence, and quality of life. Links with depression have also been documented in the literature (Granger, Cotter, Hamilton, & Fiedler, 1993; Nelles et al., 2001; Ramrattan et al., 2001; Tsai et al., 2003; West et al., 2002). The estimation of the overall prevalence of visual impairment is approximately 60% at the acute stage following stroke (Ali et al., 2013; Barrett et al., 2007; Clisby, 1995; Freeman & Rudge, 1987; Isaeff, Wallar, & Duncan, 1974; Rowe et al., 2009b; Rowe et al., 2013). A review of the individual prevalence figures and the recovery rates for each of the possible post-stroke visual impairments has been reported elsewhere in the literature (Hepworth et al., 2016).
In order to treat and manage visual impairments caused by stroke it is important to establish the range and effectiveness of the available treatment options. The aim of this literature review is to provide a comprehensive synthesis of the evidence relating to treatment of visual problems after stroke.
Background: The visual impairments caused by stroke have the potential to affect the ability of an individual to perform activities of daily living. An individual with visual impairment may also have reduced level of independence. The purpose of this review was to investigate the impact on quality of life from stroke related visual impairment, using subjective patient reported outcome measures.
Methods: A systematic search of the literature was performed. The inclusion criteria required studies to have adult participants (aged 18 years or over) with a diagnosis of a visual impairment directly resulting from a stroke. Studies which included visual impairment as a result of other intracranial aetiology, were included if over half of the participants were stroke survivors. Multiple scholarly online databases and registers of published, unpublished and ongoing trials were searched, in addition articles were hand searched. MESH terms and alternatives in relation to stroke and visual conditions were used. Study selection was performed by two authors independently. Data was extracted by one author and verified by a second. The quality of the evidence was assessed using a quality appraisal tool and reporting guidelines.
Results: This review included 11 studies which involved 5646 participants, the studies used a mixture of generic and vision-specific instruments. The seven instruments used by the included studies were the EQ-5D, LIFE-H, SF-36, NEI VFQ-25, VA LV VFQ-48, SRA-VFP and DLTV.
Conclusion: A reduction in quality of life was reported by all studies in stroke survivors with visual impairment. Some studies used generic instruments, therefore making it difficult to extract the specific impact of the visual impairment as opposed to the other deficits caused by stroke. The majority of studies (8/11) primarily had participants with visual field loss. This skew towards visual field loss and no studies investigating the impact ocular motility prevented a comparison of the effects on quality of life due to different visual impairments caused by stroke. In order to fully understand the impact of visual impairment following stroke on quality of life, further studies need to use an appropriate vision-specific outcome measure and include all types of visual impairment which can result from a stroke.
Approximately one-third of the human brain controls visual anatomy or transmits and registers visual information (Kapoor & Ciuffreda, 2002). Because of this, acquired brain injuries ABI can frequently cause visual impairment.
Following an ABI, it is important for visual deficits to be taken into account and addressed during occupational therapy evaluation and treatment. Although considered a primary sense for obtaining information, vision is often ignored or overlooked in rehabilitation programs. Vision screens should be conducted and collaborations and referrals to a neuro-optometrists made. There is a lack of research regarding the benefits of visual interventions with individuals that are more than two years post-injury.
The project looked at benefits of addressing visual deficits in individuals who have experienced a ABI and are five years or more post-injury. A vison program was established at a day enrichment center for individuals’ years postinjury. Vision programs were established in collaboration with a neuro optometrist and performed at an inpatient brain injury rehabilitation center.
Two different case studies and a pilot study detail the benefits of a comprehensive vison program in individuals who have experienced a traumatic brain injury. A pilot study was conducted to monitor the benefits of development of a program to address visual deficits effecting reading with individuals more than five years post-brain injury. There is potential for ocular motor deficits such as pursuits and saccades to improve with continued training and for improvements in visual deficits to improve performance in activities of daily living
Aim: The aim of this literature review was to determine the reported incidence and prevalence of visual impairment due to stroke for all visual conditions including central vision loss, visual field loss, eye movement problems and visual perception problems. A further aim was to document the reported rate and extent of recovery of visual conditions post stroke.
Methods: A systematic review of the literature was conducted including all languages and translations obtained. The review covered adult participants (aged 18 years or over) diagnosed with a visual impairment as a direct cause of a stroke. Studies which included mixed populations were included if over 50% of the participants had a diagnosis of stroke. We searched scholarly online resources and hand searched journals and registers of published, unpublished and ongoing trials. Search terms included a variety of MESH terms and alternatives in relation to stroke and visual conditions. The quality of the evidence was assessed using key reporting guidelines, e.g. STROBE, CONSORT.
Results: Sixty-one studies (n=25,672) were included in the review. Overall prevalence of visual impairment early after stroke was estimated at 65%, ranging from 19% to 92%. Visual field loss reports ranged from 5.5% to 57%, ocular motility problems from 22% to 54%, visual inattention from 14% to 82% and reduced central vision reported in up to 70%. Recovery of visual field loss varied between 0% and 72%, with ocular motility between 7% and 92% and visual inattention between 29% and 78%.
Conclusion: The current literature provides a range of estimates for prevalence of visual impairment after stroke. Visual impairment post stroke is a common problem and has significant relevance to the assessment and care these patients receive. Prospective figures regarding incidence remain unknown.
In patients with brain damage, often the hemianopic field defect is not diagnosed, because other neurological symptoms, such as hemiplegia, are predominant. The mean time between the brain damage and the diagnosis of the hemianopia was found to be 3 +/- 2 months (Zhang et al 2006). Additionally, the patients oft en do not realize the fi eld defect, even though they experience activity limitations in their everyday life. The classification of the World Health Organizati on (WHO 2004) for Functioning, Disability and Health (ICF) includes three main aspects, which have to be considered in visual impairment:
Homonymous field defects cause two main disabilities/ activity limitations:
…A novel, tablet-based application (app) has been developed to act as a screening tool for visual impairment in stroke survivors; The Stroke Vision app. The app includes assessments for visual acuity, visual fields and visuospatial neglect, as well as novel tools for the education of patients, carers and staff. The app has been devised by experts in the field to address two important deficiencies; firstly a set of visual assessment tools to support and improve evaluation and rehabilitation of visual impairments in stroke survivors, and secondly to provide education for staff and information to carers about their relatives visual disabilities…