Tracey Shipman

Visual impairment following stroke: do stroke patients require vision assessment?

BACKGROUND the types of visual impairment followings stroke are wide ranging and encompass low vision, eye movement and visual field abnormalities, and visual perceptual difficulties. OBJECTIVE the purpose of this paper is to present a 1-year data set and identify the types of visual impairment occurring following stroke and their prevalence. METHODS a multi-centre prospective observation study was undertaken in 14 acute trust hospitals. Stroke survivors with a suspected visual difficulty were recruited. Standardised screening/referral and investigation forms were employed to document data on visual impairment specifically assessment of visual acuity, ocular pathology, eye alignment and movement, visual perception (including inattention) and visual field defects. RESULTS three hundred and twenty-three patients were recruited with a mean age of 69 years [standard deviation (SD) 15]. Sixty-eight per cent had eye alignment/movement impairment, 49% had visual field impairment, 26.5% had low vision and 20.5% had perceptual difficulties. CONCLUSIONS of patients referred with a suspected visual difficulty, only 8% had normal vision status confirmed on examination. Ninety-two per cent had visual impairment of some form confirmed which is considerably higher than previous publications and probably relates to the prospective, standardised investigation offered by specialist orthoptists. However, under-ascertainment of visual problems cannot be ruled out.

A Prospective Profile of Visual Field Loss following Stroke: Prevalence, Type, Rehabilitation, and Outcome

Aims. To profile site of stroke/cerebrovascular accident, type and extent of field loss, treatment options, and outcome. Methods. Prospective multicentre cohort trial. Standardised referral and investigation protocol of visual parameters. Results. 915 patients were recruited with a mean age of 69 years (SD 14). 479 patients (52%) had visual field loss. 51 patients (10%) had no visual symptoms. Almost half of symptomatic patients (n = 226) complained only of visual field loss: almost half (n = 226) also had reading difficulty, blurred vision, diplopia, and perceptual difficulties. 31% (n = 151) had visual field loss as their only visual impairment: 69% (n = 328) had low vision, eye movement deficits, or visual perceptual difficulties. Occipital and parietal lobe strokes most commonly caused visual field loss. Treatment options included visual search training, visual awareness, typoscopes, substitutive prisms, low vision aids, refraction, and occlusive patches. At followup 15 patients (7.5%) had full recovery, 78 (39%) had improvement, and 104 (52%) had no recovery. Two patients (1%) had further decline of visual field. Patients with visual field loss had lower quality of life scores than stroke patients without visual impairment. Conclusions. Stroke survivors with visual field loss require assessment to accurately define type and extent of loss, diagnose coexistent visual impairments, and offer targeted treatment.

Reading difficulty after stroke: ocular and non ocular causes.

Background Ocular causes of reading impairment following stroke include visual field loss, eye movement impairment and poor central vision. Non ocular causes may include cognitive errors or language impairment. Aim The purpose of this study was to identify all patients referred with suspected visual impairment who had reported reading difficulty to establish the prevalence of ocular and non ocular causes. Methods Prospective, multicentre, observation study with standardised referral and assessment forms across 21 sites. Visual assessment included visual acuity measurement, visual field assessment, ocular alignment, and movement and visual inattention assessment. Multicentre ethical approval and informed patient consent were obtained. Results A total of 915 patients were recruited, with a mean age of 69·18 years (standard deviation 14·19). Reading difficulties were reported by 177 patients (19·3%), with reading difficulty as the only symptom in 39 patients. Fifteen patients had normal visual assessment but with a diagnosis of expressive or receptive aphasia. Eight patients had alexia. One hundred and nine patients had visual field loss, 85 with eye movement abnormality, 27 with low vision and 39 patients with visual perceptual impairment. Eighty-seven patients had multiple ocular diagnoses with combined visual field, eye movement, low vision or inattention problems. All patients with visual impairment were given targeted treatment and/or advice including prisms, occlusion, refraction, low vision aids and scanning exercises. Conclusions Patients complaining of reading difficulty were mostly found to have visual impairment relating to low vision, eye movement or visual field loss. A small number were found to have non ocular causes of reading difficulty. Treatment or advice was possible for all patients with visual impairment.

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

PurposeThe 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.MethodA 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.ResultsA 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.ConclusionNo 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.

A randomised controlled trial to compare the clinical and cost-effectiveness of prism glasses, visual search training and standard care in patients with hemianopia following stroke: a protocol

Introduction Homonymous hemianopia is a common and disabling visual problem after stroke. Currently, prism glasses and visual scanning training are proposed to improve it. The aim of this trial is to determine the effectiveness of these interventions compared to standard care. Methods and analysis The trial will be a multicentre three arm individually randomised controlled trial with independent assessment at 6 week, 12 week and 26 week post-randomisation. Recruitment will occur in hospital, outpatient and primary care settings in UK hospital trusts. A total of 105 patients with homonymous hemianopia and without ocular motility impairment, visual inattention or pre-existent visual field impairment will be randomised to one of three balanced groups. Randomisation lists will be stratified by site and hemianopia level (partial or complete) and created using simple block randomisation by an independent statistician. Allocations will be disclosed to patients by the treating clinician, maintaining blinding for outcome assessment. The primary outcome will be change in visual field assessment from baseline to 26 weeks. Secondary measures will include the Rivermead Mobility Index, Visual Function Questionnaire 25/10, Nottingham Extended Activities of Daily Living, Euro Qual-5D and Short Form-12 questionnaires. Analysis will be by intention to treat. Ethics and dissemination This study has been developed and supported by the UK Stroke Research Network Clinical Studies Group working with service users. Multicentre ethical approval was obtained through the North West 6 Research ethics committee (Reference 10/H1003/119). The trial is funded by the UK Stroke Association. Trial Registration: Current Controlled Trials ISRCTN05956042. Dissemination will consider usual scholarly options of conference presentation and journal publication in addition to patient and public dissemination with lay summaries and articles. Trial Registration Current Controlled Trials ISRCTN05956042.

Profile of Gaze Dysfunction following Cerebrovascular Accident

Aim. To evaluate the profile of ocular gaze abnormalities occurring following stroke. Methods. Prospective multicentre cohort trial. Standardised referral and investigation protocol including assessment of visual acuity, ocular alignment and motility, visual field, and visual perception. Results. 915 patients recruited: mean age 69.18 years (SD 14.19). 498 patients (54%) were diagnosed with ocular motility abnormalities. 207 patients had gaze abnormalities including impaired gaze holding (46), complete gaze palsy (23), horizontal gaze palsy (16), vertical gaze palsy (17), Parinauds syndrome (8), INO (20), one and half syndrome (3), saccadic palsy (28), and smooth pursuit palsy (46). These were isolated impairments in 50% of cases and in association with other ocular abnormalities in 50% including impaired convergence, nystagmus, and lid or pupil abnormalities. Areas of brain stroke were frequently the cerebellum, brainstem, and diencephalic areas. Strokes causing gaze dysfunction also involved cortical areas including occipital, parietal, and temporal lobes. Symptoms of diplopia and blurred vision were present in 35%. 37 patients were discharged, 29 referred, and 141 offered review appointments. 107 reviewed patients showed full recovery (4%), partial improvement (66%), and static gaze dysfunction (30%). Conclusions. Gaze dysfunction is common following stroke. Approximately one-third of patients complain of visual symptoms, two thirds show some improvement in ocular motility.

A pilot randomized controlled trial comparing effectiveness of prism glasses, visual search training and standard care in hemianopia

Pilot trial to compare prism therapy and visual search training, for homonymous hemianopia, to standard care (information only).

A Randomised Controlled Trial of Treatment for Post-Stroke Homonymous Hemianopia: Screening and Recruitment

ABSTRACT The authors report the screening process and recruitment figures for the VISION (Visual Impairment in Stroke; Intervention Or Not) trial. This is a prospective, randomised, single-blinded, three-arm controlled trial in 14 UK acute hospital stroke units. Stroke teams identified stroke survivors suspected as having homonymous hemianopia. Interventions included Fresnel prisms versus visual search training versus standard care (information only). Primary outcome was change in visual field assessment from baseline to 26 weeks. Secondary measures included change in quality-of-life questionnaires. Recruitment opened in May 2011. A total of 1171 patients were screened by the local principal investigators. Of 1171 patients, 178 (15.2%) were eligible for recruitment: 87 patients (7.4%) provided consent and were recruited; 91 patients (7.8%) did not provide consent, and 993 of 1171 patients (84.8%) failed to meet the eligibility criteria. Almost half were excluded due to complete/partial recovery of hemianopia (43.6%; n = 511). The most common ineligibility reason was recovery of hemianopia. When designing future trials in this area, changes in eligibility criteria/outcome selection to allow more patients to be recruited should be considered, e.g., less stringent levels of visual acuity/refractive error. Alternative outcomes measurable in the home environment, rather than requiring hospital attendance for follow-up, could facilitate increased recruitment.

Decompensating esophoria as the presenting feature of myasthenia gravis

Myasthenia gravis is a disease in which antibodies directed at nicotinic acetylcholine receptors are produced, leading to a deficiency of acetylcholine receptors at the neuromuscular junction. This results in impairment of muscular excitation, which appears clinically as fatigable muscle weakness. Weakness of the extraocular muscles occurs in nearly 90% of all myasthenics at disease onset, with ptosis being the most common presenting feature. Myasthenia gravis affecting one or a combination of the extraocular muscles without ptosis is less common; however, cases such as bilateral internuclear ophthalmoplegia without ptosis have been described in the literature. The authors present a case in which decompensating esophoria was the presenting feature of myasthenia gravis.