Persistent Visual Impairments following Mild-to-Moderate Ischemic Stroke

Chamini Niroshika Wijesundera^1,2Sheila Gillard Crewther^1,2*Tissa Wijeratne^2,3,4Algis J Vingrys⁵

• ¹La Trobe University, Melbourne, Australia
• ²Department of Neurology, Sunshine Hospital, Melbourne, Australia
• ³RMIT University, Melbourne, Victoria, Australia
• ⁴Department of Medicine, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Anuradhapura, Sri Lanka
• ⁵Department of Optometry and Vision Sciences, Melbourne School of Health Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Carlton, Victoria, Australia

Background: Vision is rarely appraised either acutely or during recovery, following acute ischemic stroke. Our previous study found significant deficits in visual function after 2-3 days in ~ 68% of hospitalized mild-to-moderate acute ischemic stroke (AIS) patients with no comorbid eye disease. The purpose of this study was to evaluate recovery in vision after 2-6 months in a subgroup of the original participants.Methods: Visual assessments were performed within the first week of admission and 2-6 months later. Testing was achieved on an iPad and included visual acuity (VA), VA-in-noise, visual field, visual neglect and time to complete an eye-hand coordination (EHC) task. All cases were radiologically confirmed and 10 had left hemisphere lesions. Outcomes were compared to twenty age matched healthy controls who were tested and retested over a similar duration using the same vision tests. Testing took 12 minutes.Results: During the first week of admission, 19/20, (95%) AIS patients returned normal visual acuity (>6/12 VA, p=0.11) yet 11/20 (55%) had reduced VA-in-noise (p<0.000).Visual neglect was present in 2/20 cases. Visual field defects were present in 16/20 (80%, p<0.001) with 7/16 (44%) being unaware of their visual field loss. All patients chose to use their dominant right hand despite 10 having left hemisphere lesions and 13/20 (65%, p<0.001) returning longer times to complete the EHC tracing tasks. After 2-6 months of recovery, all stroke patients returned normal visual attention, normal VA although 3/20 (15%) continued to show reduced VA in the presence of noise masks. Seven/20 (35%) retained visual field defects and 8/20 (40%, 3 right and 5 left hemisphere lesions) had visuomotor impairment. Posterior circulation territory strokes and left hemisphere lesions were more likely to result in a persistent visual field loss and visuomotor deficit.Conclusion: Given that stroke is the leading cause of neurological disability affecting over 110 million people, our findings highlight the necessity for both acute and longitudinal vision assessments subsequent to mild stroke. Exposing the persistent limitations in visual functions could aid identifying suitability for driving and the visuomotor rehabilitation of stroke survivors.