Complete Homonymous hemianopia

Homonymous hemianopia with macular sparing

Homonymous Quadrantopia

A hemianopia is complete when the defect follows the vertical meridian, has macular splitting and involves the entire hemifield of the affected side

All other visual field defects are termed as incomplete and can be congruous or incongrous

(Biousse 2010,Up To Date)

Left Eye Right Eye

Hemianopia

Confrontation testing

Perimertry (Humphrey and Goldmans)

Line bisection error analysis

Observation in function

There are various techniques, they are usually kinetic or static and are widely used at bedside

Confrontation testing was found to have inadequate sensitivity as a screen (74%). Although kinetic testing was superior to static tests

Improved sensitivity was found when confrontation tests were combined (78%)

Specificity was found to be 93%

Previous studies have found that patients with Homonymous Hemianopia make contralesional line bisection errors towards their affected hemifield

Schuett et al (2010) found that this error was made independent of the type of visual field defect

It is believed to be related to an underlying visual spatial disorder

Still unclear if this test could be used as a reliable screening tool for visual field defect

Wall trailing

Head turning/tilting

Hesitancy

Stopping suddenly

Giving a wide berth

Going a long way round

Laboured scanning strategy◦ Increase in saccades to blind field

◦ Inconsistant exploration of space

(Zihl 2000, Pambakakian 2000)

Reading Collisions Shopping Anxiety/loss of confidence Driving Knocking things over Financial management Meal preparation Disorientation (Warren 2010,Pambakian 2000,Papageorgiou 2007)

Substitution/Optical therapy, not currently recommended for routine practice by the RCP guidelines (2008)

Compensation, RCP(2008) guidelines recommend that techniques should be taught to overcome VF loss

Restitution, not currently recommended

Recommendations based on 2 systematic reviews, Riggs(2007) and Bouwmeester (2006)

This novel prism placement was first trialled by Peli et al (2000), who found positive results but it was only a small trial

Previously prism placement had caused distortion and diplopia

Bowers et al(2008) trial was a larger and multi centred n=43 but was not randomised and there was no control group (although an RCT is underway but has not yet been published)

Bowers found positive acceptance by patients who found them useful in mobility and obstacle avoidance (74% wearing at 6 weeks,47% at 12 months)

What is Compensation in the literature?◦ Saccadic visual search training(Pambakian

2004),explorative saccade training(Roth 2009) and visual search training (Schofield 2009)

◦ All based on mass practice using computer based technology for about 30 mins daily over a six week period

◦ Improvement is mainly measured in terms of response time of patients scanning into the hemianoptic field

◦ There is strengthening evidence that this training does improve scanning into the hemianoptic field but what is less clear is its impact on ADL’s

Did Angela receive typical current OT’s practice?

How else do we encourage compensation?

Do we target response time or accuracy? Is there a trade off?

outside foveal vision to

identify

How do you read text?

Left Eye Right Eye

Hemianopia

text reading fixations – normal subject

36 fixations 45 words: ratio = 0.8

text reading fixations – hemianopic alexia

93 fixations 45 words: ratio = 2.1

Rehabilitation sitehttp://www.readright.ucl.ac.uk/

Demo: therapy

Paperclip

Outcome = time on visual search in naturalistic

scenes.

76 year old lady lives with husband, previously independent

Had surgery on 29/06/10 to correct complicated cataract surgery,this resulted in loss af vision in left eye

Suffered a CVA post surgery

MR brain showed left Occipital and Cerebellar infarcts

Right VF defect suspected through screening

Look out for increasing evidence into the use of prisms

Be ready to do mass scanning practice using technology either at home or in hospital

Combine screening methods to assess for Visual field defects

Visual field defects can confound other visual perceptual problems as well as cause them

Kerr et al (2010) Diagnostic accuracy of confrontation visual field tests,Neurology,13;74(15):1184-90

Pambakian et al (2000)Scanning the visual world:a study of patients with homonymous hemianopia. Journal of neurology Neurosurgery and psychiatry 69:751-9

Schuett et al (2010),Line bisection in unilateral homonymous visual field defects, Cortex,doi:10.1016/j.cortex.2010.01.008