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.