Date Published: March 6, 2019
Publisher: Public Library of Science
Author(s): Fiona J. Rowe, Lauren R. Hepworth, Claire Howard, Kerry L. Hanna, Christopher P. Cheyne, Jim Currie, Alfred S. Lewin.
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.
Multi-centre acute stroke unit, prospective, epidemiology study (1st July 2014 to 30th 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.
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.
The prevalence of overall visual problems has been estimated at 65% with varying prevalence reported for specific types of visual problems [1–4]. For example, visual field loss is reported in up to 52% of stroke survivors, central visual problems in up to 70%, eye movement disorders in up to 68% and visual perceptual disorders (inclusive of visual inattention) in up to 80% of stroke survivors [1,3,5,6]. The wide ranges relate to the design of source studies with a mix of randomised controlled trials through to observation cohort studies, and also relate to mixed stroke populations, purposeful samples and varying time periods from stroke onset to visual assessment. Figures for incident new onset visual sequelae following stroke are not reported in the published literature.
During the one-year period of 1st July 2014 to 30th June 2015, there were 1295 stroke admissions across the three hospital stroke units. Results were pooled for analysis for all three stroke units, after an independent samples analysis (chi square test for gender/type of stroke; Kruskal-Wallis test for age/duration) across the three stroke units showed no difference in distribution for gender (p = 0.51), age at stroke onset (p = 0.15), type of stroke (p = 0.51) or duration before full visual assessment was possible (p = 0.25).
This is, to our knowledge, the first large study of stroke admissions over a 1-year period to meticulously determine the incidence of stroke-related visual sequelae and timing of vision assessment. The first attempted visual assessment was made at a median of 3 days post stroke onset. The time-point at which most stroke survivors could achieve a full visual assessment was at a median of 4 days post stroke onset. This contrasts with the Vision In Stroke (VIS) study which recruited stroke survivors referred for orthoptic assessment because of suspected visual problems at a median of 22 days (mean 40.8) . However, by the nature of the VIS referral—because of suspected visual problems—this indicates prior screening in which stroke teams used a standardised screening form . Thus, a later time-point to full assessment is to be expected from the VIS study.
In this population of acute stroke unit admissions, point prevalence of visual problems ranges from 58% for all stroke admissions to 73% for all stroke survivors undertaking visual assessment. Incidence of new onset visual sequelae due to stroke ranges from 48% for all stroke admissions to 60% for all stroke survivors undertaking visual assessment.