Car Driving Performance in
Hemianopia Patients:
the Effect of Compensatory Scanning Training
Bart J.M. Melis- Dankers, PhD
Special thanks to:
Gera de Haan, Joost Heutink, Wiebo Brouwer
University of Groningen – Clinical and Developmental Neuropsychology
Royal Dutch Visio – Centre of expertise for blind and partially sighted people
Regulations - NL
Ministry of Transport, 2009/2010:
Horizontal Visual Field (HVF):
 HVF > 120°
: unrestricted driving license
-- at least 50° right/left, + 20° up/down
-- no binocular scotoma in central 20° field

HVF < 90°
: not fit to drive

90°< HVF<120°
: driving test possible
Hemianopia - safe drivers


Tant (2002)
Brouwer (2013)
Racette&Casson (2005)
Owsley-group (2009/2011)

In general:


◦
◦
◦
◦
◦
◦
-
4/28 (14%)
7/17 (42%)
8/20 (40%)
23/30 (77%)
steering instability and unsuitable positioning on the road
difficulties with gap judgment
driving too slow or too fast
too much sudden braking
inconsequent viewing behavior
poor reaction to unexpected events
Participants in driving study
N = 26 adults reporting mobility problems because of a
homonymous hemianopia
 M(TimeSinceLesion) = 14.8 months [6 - 41]
 N = 21 left-sided, N = 5 right-sided hemianopia
 N = 18 male, N = 8 female
 M(age) = 52 [27-71, SD = 11.7]
 M(DrivingExperience) = 29 years [3 – 53]




No severe motor, (neuro)psychologic or hearing disorders
No ophthalmologic dysfunctioning;
Binocular visual acuity ≥ 0.5
5
Design
Training group
T1
Training
T2
pre
post
Control group
T1
T2
Training
T3
-3mth
Tests on T1, T2 and T3:
 Impaired Mobility Questionnaire (IMQ; Turano, 1999)
 Obstacle course (with dual task)
 Tracking Task
 Hazard perception (Vlakveld, 2011)
---------------------------------------------------------------------------- Driving simulator
 Practical fitness to drive [CBR]
6
Obstacle course
(dual task)
Walking time (sec)
90
80
70
60
50
40
30
20
10
0
pre
post
Result
no dual
task
dual task
free course
no dual
task
dual task
obstacle course
Tracking task
RT (ms) on blind and seeing side
1600
1540
1306
990
1200
866
800
pre
post
400
0
blind
Result seeing
Total omissions on blind and seeing side
7
8
6
pre
4
1
post
2
0
0
0
blind
seeing
Hazard perception
Vlakveld-test
With eye movement recording
Keep on going?
Foot off gas pedal?
Break?
Keep on going?
Foot off gas pedal?
Break?
Keep on going?
Foot off gas pedal?
Break?
Driving simulator
slightly winding road
 slightly winding road
 slightly winding road
 rural, 2-lane road + crossings
 rural, 2-lane road + crossings

fixed speed (50 km/h)
free speed
instruction: in a hurry
fixed speed
free speed
15
Practical Fitness to drive: TRIP




Test Ride for Investigating Practical fitness to drive
57 items: insufficient, doubtful, sufficient
Driving test taken by ‘blind’ CBR-expert
Factors:
◦ VIS: visual factor
◦ OPER: operational factor
◦ TACT: tactical factor

Scores:
◦ 1 = insufficient
◦ 2 = doubtful
◦ 3 = sufficient / good
16
Fitness to drive






N = 26 Hemianopia patients (total N = 57)
N = 21 left-sided, N = 5 right-sided hemianopia
N = 18 male, N = 8 female
M(Age) = 52 [27-71]
CBR (Dutch department of motor vehicles)
2 on-road driving assessments:
12 failed
(46%)
Before onset of training (N=26)
14 passed
(54%)
17
Fitness to drive: total group

VIS
◦ Insufficient 15%
◦ Doubtful 13%
◦ Sufficient 72%

OPER
◦ Insufficient 10%
◦ Doubtful 11%
◦ Sufficient 79%

TACT
◦ Insufficient 11%
◦ Doubtful 13%
◦ Sufficient 76%
Reasons for negative judgement
VIS
Total
(N=26)
Fit to drive
(N=14)
Unfit to drive (N=12)
p-valuea
2.59 (0.52)
2.92 (0.10)
2.20 (0.53)
<.001**
OPER
TACT
GLOB
2.71 (0.48)
2.97 (0.07)
2.40 (0.58)
<.001**
2.66 (0.42)
2.92 (0.10)
2.36 (0.44)
<.001**
2.50 (0.65)
3.00 (0.00)
1.92 (0.52)
<.001**
19
Patient characteristics

No effect on TRIP subscales:
◦ Age, Gender, and Years of driving experience
◦ Time since onset, but:
 longer time since onset > lower VIS (p=.072)

Time not driven (M=15 months, 0-72):
◦ Trend for difference between the “fit” and “unfit”
drivers (p=.060)
◦ The more time the patient had not driven, the lower
the scores on VIS (p=.014) and OPER (p=.010)
◦ No significant correlation for TACT (p=.159)
Compensatory Scanning Training
Royal Dutch Visio: 18 hours of training
 Aimed at improving “slow mobility”

1. Increase insight
2. Systematic scanning strategy
3. Transfer to mobility in daily life
Fitness to drive






N = 26 Hemianopia patients (total N = 57)
N = 21 left-sided, N = 5 right-sided hemianopia
N = 18 male, N = 8 female
M(Age) = 52 [27-71]
CBR (Dutch department of motor vehicles)
2 on-road driving assessments:
12 failed
(46%)
Before onset of training (N=26)
14 passed
(54%)
5 failed
After training (N=9)
4 passed
22
Fitness to drive: TRIP
TRIP-factors improve after training (N = 9)
3
2.5
Drive1
Drive2
2
1.5
1
VIS
OPER
TACT
GLOB
TOT
23
Driving simulator
24
Effect of training: VIS
Conclusion
Self-reported mobility in daily life improved (IMQ)
 Faster responses to stimuli in the blind periphery (Tracking Task)
 Higher walking speed in obstacle course with cognitive dual task
 Part of patients with hemianopiae is practical fit to drive,
even without training.
 Visual aspects of driving are most problematic.
 Negative judgement due to insufficient viewing strategy,
but also due to operational and tactical driving.
 Training improves visual and tactical aspects.
 No age-related effect found.
-------------------------------------------------------------------------------------Hemianopia does not necessarily impair fitness to drive

27
University of Groningen
 Gera de Haan
 Royal Dutch Visio, Bartiméus  Joost Heutink
 CBR
 Wiebo Brouwer
 ZonMw – InZicht
 Oliver Tucha

Thank you for your attention
Contact: BartMelis@visio.org