Prism glasses
An optical plastic membrane that displaces the images viewed through the prism, aiming to bring the lost side of the visual field back into view.
A clinical trial in stroke vision rehabilitation
VISION: Vision Impairment in Stroke, Intervention Or Not
VISION is a clinical trial that compares the effectiveness of prism glasses, visual search and standard care (information only) in patients who have a homonymous hemianopia following a stroke.
Vision Impairment in Stroke: Intervention Or Not
About the trial
Three approaches, compared in one randomised trial
Participants are randomly assigned to one of three treatment methods. The trial then measures visual field and quality of life to find out which approach works best.
Visual search training
Training that encourages a person to look systematically to the right and to the left, so the blind side of the visual field is scanned more often.
Information only
The control group receives information about visual field loss and standard care, with no additional rehabilitation therapy.
Why VISION matters
Visual field loss after stroke is common and under served
A stroke can affect people in many different ways and leave a range of persisting side effects. Visual field loss is one of the most commonly reported, and it can seriously affect functional ability and quality of life. People who lose part of their visual field after a stroke can be more prone to falls, and their participation in rehabilitation may be hampered. Despite this, service provision for stroke patients with suspected visual field loss is inconsistent, and there are no clear guidelines on how these patients should be visually rehabilitated.
VISION was undertaken to explore the visual rehabilitation of patients who lose either the left or the right half of the visual field in both eyes, a condition known as homonymous hemianopia, following a stroke.
3
Treatment arms compared
3
Assessment points at 6, 12 and 26 weeks
1
Condition studied: homonymous hemianopia
How the trial works
From randomisation to follow up assessment
What is measured
Visual field assessments take place at 6, 12 and 26 weeks after treatment starts. A quality of life questionnaire is completed by participants at the same points.
By combining these measures, the trial hopes to show whether rehabilitation methods improve functional outcome more than information alone.
What the trial hopes to answer
The trial also hopes to establish whether prism glasses or visual search training are the most effective at improving functional outcome.
Read the glossary of terms to understand the language used in the trial, from homonymous hemianopia to visual scanning.
Latest news
Website released
13 May 2011
The VISION trial Website was released to share the trial background, the collaborative team and the recruiting centres with patients, clinicians and researchers.