The influence of monocular peripheral sector prisms on driving in people with homonymous hemianopia

Bart J.M. Melis-Dankers, PhDVISIO, Dutch National Foundation for visually impaired and blind people

BiOptic Driving Conference, London, UK18 – 20 June, 2004

University of Groningen, Groningen, the Netherlands• Rens B. Busscher, MSc• prof. Wiebo. H. Brouwer, PhD • prof. Aart. C. Kooijman, PhD

Schepens Eye Research Institute, Boston, USA• prof. Eli Peli, PhD• Alex Bowers, PhD

Belgian Road Safety Institute (BIVV), Brussels, Belgium• Mark L.M. Tant, PhD

Dutch Central Driving Test Organisation (CBR)• Ruud A. Bredewoud, MD• Sander Bison

Visio, Haren, The Netherlands• Gert Dobbe

Mark L.M. Tant, PhDVisual Performance in Homonymous Hemianopia:Assesment, training and driving

Tanja R. M. Coeckelbergh, PhDEffect of compensatory viewing strategies on

practical fitness to drive in subjects with visual field defects

caused by ocular pathology

history

(left) hemianopia

left hemianopia, gaze right Eli Peli

normal view

left hemianopia, gaze left Eli Peli

normal view

left hemianopia, gaze far left Eli Peli

normal view

• Corrected binocular visual acuity:VODS ≥ 0,5 (VA ≥ 10/20)VODS ≥ 0,6, for monocular viewers (VA ≥ 12/20)No exceptions

• Visual field:Horizontal visual field ≥ 140 degreesException possible after special driving exam byDutch Central Driving Test Organisation (CBR)

legal requirements for drivingin the Netherlands

left hemianopia

MPSPmonocular peripheral sector prisms

Eli Peli

expected gain of visual field usingMPSP

left hemianopia

left eye right eye

simulated gain of visual field usingMPSP

left hemianopia

left eye right eye

• number of subjects: 22 recruited17 included

• gender: male: 15female: 2

• age: 56 years (range: 28 – 74)• hemianopia: RHH: 7

LHH: 10• years since injury: 5,5 years (range 2 – 13)• VODS: 0,8 ≤ VODS ≤ 1,6

(16/20 ≤ VA ≤ 32/20)all macular sparing

subjects

• left or right hemianopia• with or without macular sparing• age ≥ 18 years• licensed or former driver• generally good health• no physical / mental disabilities• no hemi-neglect

inclusion criteria

• test for inclusion• visual and neuropsychological testing• standardised test ride without MPS-prism• fitting of upper MPS-prism• adaptation period: two weeks• fitting of lower MPS-prism• adaptation period: two weeks• Goldmann perimetry (binocular, with MPS-prism)• 2 standardised test rides (random order):

- 1 with MPS-prism- 1 with mock prism

protocol

• 3 standardised test rides (random)- no MPS-prism- mock prism- with MPS-prism

• video records• CBR: TRIP-scores / practical fitness-to-drive• investigator in back seat

test ride

OS

no MPSP

LHH

ODS

with MPSP

LHH

OD

no MPSP

LHH

binocular field

expansion onGoldmannperimetry:

17 / 17

objectiveresults

practical fitness to drive: no MPSP mock MPSP

with MPSPfailed: 10 10 11doubt: 3 3 4passed: 4 4 2

• improved with MPSP: 2• deteriorated with MPSP: 5• no change with MPSP: 10• passed without MPSP – failed/doubt with MPSP: 3• failed without MPSP – passed with MPSP: 1

objective results

• effectivity of MPS-prism for driving:- negative: 10- neutral: 4- positive: 3

• comfort of MPS-prism for driving:- negative: 9- neutral: 5- positive: 3

• still using MPS-prism for driving:- no : 13- yes, appreciation moderate: 2- yes, appreciation good: 2

subjective results

Without proper training and supervised driving practice

patients experience distraction by MPSP which leads to disappointing results.

Belgium protocol:• 16 subjects and 4 controls• instruction directed at awareness of peripheral

diplopia• stress significance of diary• subjects have to gain experience as passenger• two test rides with supervised driving practice• bifocal window for spot reading

conclusion and suggestions

bifocal window for spot reading

Eli Peli

THE SCHEPENS EYE RESEARCH INSTITUTE

An Affiliate of Harvard Medical School

Thank you for your attention

Visio, Dutch NationalFoundation for the blind

University of Groningen

The Schepens Eye Research Institute

Dutch Central Driving Test Organisation CBR

Belgian Road SafetyInstitute BIVV