After a stroke, some people might suffer from problems that affect their ability to see. Visual field defects impact the quality of life and interfere with the rehabilitation process. Interventions to correct these issues are essential to a successful recovery. But what types of vision therapy after stroke are available? Two such practices include prism and landscape therapy.
Using prisms and landscapes to help stroke patients recover their visual field
Researchers wanted to know how using prism and landscape therapy held up to standard rehabilitation therapies. They compared these specialized interventions with standard care protocols in patients who suffered from hemianopia (a condition that causes patients only to see half of a visual field) after a stroke. Participants of the study got 1 of 3 treatments, either prism therapy, visual search, or standard therapy.
Twenty-five patients received 2 hours of daily prism therapy (a therapy that requires patients to look through a prism to help correct vision problems). Twenty-four patients received 30 minutes of visual search training (a treatment that forces patients to train their vision by locating objects on a visual field) using landscape cards with numbered circles radiating from a central point. Control participants underwent standard care, which included leaflets that contained information about visual impairments following a stroke. Patients who received specialized therapies participated for a minimum of 6 weeks. Most of the patients had suffered a stroke an average of 11 weeks before the study began.
The researchers discovered unexpected results
Patients were assessed for improvements in their visual field area at 6, 12, and 26 weeks after starting their assigned treatments. There wasn’t as much benefit in improving other unrelated daily living tasks or activities. All three treatments showed minimal visual field improvements. The improvements were between 5% and 8%, which fell short of the 15% change that researchers were hoping to see. However, visual search training produced the most significant improvement for patients regarding vision-related quality of life.
There also appeared to be some side effects related to visual search and prism training. Almost 70% of those who participated in prism training reported a headache associated with their sessions. Others experienced problems with navigation, double vision, and optical glare or visual confusion related to their treatment. Two of the participants who received visual search training also complained of fatigue and headache. Those in the control treatment group reported no side effects.
Do specialized vision field therapies help stroke patients recover function and quality of life?
So what’s the verdict? The researchers of this study feel that clinicians who have expert knowledge on prism therapy can still utilize these exercises to benefit stroke patients. However, patients and clinicians need to be fully aware of the potential adverse effects. Although there are other studies reported here on Strokemark that support the benefits of such treatments, these findings remind us that caution should always be used. That’s why it is essential to check with your doctor or therapist before starting any new treatment.
The lead author of this study was F. J. Rowe, Department of Health Services Research, University of Liverpool, Liverpool, United Kingdom.