Perimetric homonymous visual field loss post-stroke

Abstract

Post-stroke homonymous visual field (PSHVF) loss has functional and driving implications for patients. Automated, as opposed to confrontational, assessment of PSHVF loss has the potential to provide a more reliable indicator for field loss and thus ability to drive. Sixty-one consecutive stroke admissions were assessed at 9 months post-stroke. Driving status and the patient's awareness of any visual field loss was ascertained. Patients underwent formal perimetric visual field testing using a Humphrey Visual Field Analyser II. A separate, blinded, confrontational assessment of visual fields was made using the National Institutes of Health Stroke Scale (NIHSS) technique. Homonymous field defects were found in 10 (16%) patients, with 50% of these being hemianopia and 50% quadrantanopia. Right-sided field loss was more common (70%). No patients with PSHVF loss were aware of their loss, and only two were detected using NIHSS assessment. One patient was thought to have PSHVF loss on NIHSS assessment but this was not confirmed on perimetry. Of those with significant PSHVF loss at 9 months, 30% were driving. The prevalence of PSHVF loss is relatively high and is underestimated by confrontational testing. Stroke patients are often unaware of their field loss, with up to 5% driving with significantly affected visual fields at 9 months. Perimetric testing may be useful in decision-making regarding driving eligibility post-stroke.