Bioptic Drivers in the USA: Survey of Driving Habits and Telescope Use
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Transcript of Bioptic Drivers in the USA: Survey of Driving Habits and Telescope Use
Bioptic Drivers in the USA: Survey of Driving Habits
and Telescope Use
Alex Bowers,
Doris Apfelbaum and Eli Peli
THE SCHEPENS EYE RESEARCH INSTITUTE
An Affiliate of Harvard Medical School
Driving with Bioptic in USA
Should Bioptic driving be permitted?
• Safety records and driving performance– Limited data available
• Impact on quality of life– Social and economic considerations
• Is the bioptic telescope useful as a driving aid?
Opinions
Ring scotoma & other optical limitations
Licensing
Against • Can not be overcome
• Make bioptic driving hazardous
• Only used to obtain license
For • Can be overcome with training
• Useful for driving
Do bioptic telescopes meet the driving needs of people with
reduced acuity?• Bioptic usage patterns
– Are bioptics used when driving?– How much and for which tasks?
• Driving habits– When, where, how far?– Do bioptic drivers restrict their driving?
• Quality of life– Impact of bioptic driving on quality of life
Participants
Source Location N
Prescribed bioptic at Dr Peli’s clinic
Massachusetts USA 14
Self selected, responded to ad on www.biopticdriving.org
12 USA states 1 Canadian 23
Graduates of WV Low Vision Driving Program (Chuck Huss)
West Virginia USA 12
Clients of mobility instructor (Renee Paquin)
New Hampshire USA 9
58 current or recent (in last 3 years) bioptic drivers
Sample Characteristics
Median Range
Age (yrs) 47 17 - 86
Bioptic driving (yrs) 8 0.25 - 32
Visual acuity without bioptic 6/30 6/15 – 6/72
60% Congenital ocular conditions 12% Age-related macular degeneration12% Juvenile macular dystrophy
Bioptic Telescopes Used
Majority used:• Monocular telescope 95%• 3x or 4x magnification 88%• Manufacturer: Designs for Vision 74%
Bioptic Usage Patterns
Wearing bioptic when driving
0
20
40
60
80
100
0% <10% 25% 50% 75% 100%
Percentage time worn while driving
Per
cen
tag
e o
f su
bje
cts
Time looking through biopticP
erc
en
tag
e o
f driv
ing
tim
e80
60
40
20
0
Median 5%
Bioptic use for 8 driving tasks
0
10
20
30
40
50
60
70
80
90
100
Streetnames
Road signs
Trafficlights
Overtake Pedsahead
Junctionno lights
Cardistance
Brakelights
Per
cen
tag
e o
f su
bje
cts
0
10
20
30
40
50
60
70
80
90
100
Streetnames
Road signs
Trafficlights
Overtake Pedsahead
Junctionno lights
Cardistance
Brakelights
Per
cen
tag
e o
f su
bje
cts
0
0.5
1
1.5
2
2.5
3
3.5
4
Mea
n v
isu
al d
iffic
ulty
rat
ing
Percent using bioptic for task
Visual difficulty without
Bioptics are used when driving!
• 90% would use bioptic even if not required for licensing
• BUT: Only 60% of drivers wore all the time
• Bioptic drivers only wear and use bioptic when they think that it will be useful
Driving Habits
Driving Habits Questionnaire Owsley et al (1999) J. Gerontol A Biol Sci Med Sci; 54:M203-211
General driving habitsConfident about driving:• Drive same speed as the general flow 84%• Rate quality of driving to be above average 72%• Moderately or very confident driving with bioptic 88%
But 60% used visual assistance (passenger)• Reading traffic signs• Identifying color of traffic light signals• Warning of hazards ahead• Help with directions or navigation
Distances driven
Normally-sighted: 203 miles per week(US Dept Transportation, 2003)
1000
800
600
400
200
0
Miles per week Furthest distance:60% out of state33% > 300 miles
Median: 200 miles per week
Driving difficulty in 9 situations
0 20 40 60 80 100
Rain
Night
Bright sun
Alone
Parallel park
Interstates
High traffic
Rush hour
Left turns
Percentage of subjects
Difficulty
Avoid due to vision impairment
Daytime only license restriction
Driving difficulty in 9 situations
0
10
20
30
40
50
60
Avoid due tov ision
impairment
Extremedifficulty
M oderatedifficulty
A littledifficulty
No difficulty
Fre
qu
ency
of
resp
on
se (
%)
• With the onset of visual impairment people tend to restrict their driving
Investigated whether driving is less restricted when a bioptic is used.
Compared our results to previous studies that used Driving Habits Questionnaire for visually impaired driving without bioptics
• Hypothesis: Bioptic drivers would have less restricted habits
than non-bioptic drivers with similar visual acuity of a similar age
Bioptic drivers compared to non-bioptic drivers with AMD1
N Age Visual Acuity
Bioptic CFL
Bioptic drivers with central field loss over 55 yrs
11 75 ± 8 6/38
Non-Bioptic AMD1
Non-bioptic with age-related macular degeneration
30 76 ± 7 6/33
1. DeCarlo et al (2003) Optom Vis Sci; 80:207-213
General driving habits
Bioptic CFL
Non-Bioptic AMD
Miles per week 45 10
Drive same speed as general flow (%)
73* 47*
Quality of driving above average (%)
82* 57*
* Chi square, p = 0.1
Percentage reporting no difficulty with driving
0
20
40
60
80
100
Rain Night Rush hour Interstates
Per
cen
tag
e o
f su
bje
cts
Bioptic CFL
Non-Bioptic AMDp < 0.02
Percentage avoiding driving
0
20
40
60
80
100
Rain Night Rush hour Interstates
Pe
rce
nta
ge
of
su
bje
cts
Bioptic CFL
Non-Bioptic AMDp < 0.05
Quality of life
0
20
40
60
80
100
Not at all A little Moderately A lot
Pe
rce
nta
ge
of
su
bje
cts
Impact of bioptic use on quality of life
Employment
For subjects aged ≤ 65 years:
• 90% were employed
• 85% drove to work
Bioptics do meet the driving needs of people with reduced acuity
• Bioptics are used when driving
• Bioptics have a positive effect on driving habits and freedom of movement
• Quality of life is enhanced through being permitted to drive with a bioptic
Future research
• Objective measures of bioptic usage
• Evaluation of driving performance with and without bioptic
Acknowledgements
• Subject recruitment– Chuck Huss (West Virginia Low Vision
Driving Program)
– Renee Paquin (New Hampshire Association for the Blind)
– Bioptic Drivers Network (www.biopticdriving.org)
Supported in part by NIH grant #EY12890
Thank you!
Bioptic drivers compared to non-bioptic drivers with
cataract1 and normal sight1
N Age VA
Bioptic Over 55Bioptic drivers > 55 yrs
15 71 ± 10 20/120
Non-bioptic Cataract1
Non-bioptic, cataract > 55yrs279 71 ± 6 20/34
Normal1
Normally sighted > 55yrs105 67 ± 6 20/20
1. Owsley et al (1999) J. Gerontol A Biol Sci Med Sci; 54:M203-211
Percentage reporting driving difficulty
0
20
40
60
80
100
Rain Night RushHour
Interstates Alone Left Turns
Per
cen
tag
e o
f su
bje
cts
Bioptic Over 55
Non-Bioptic Cataract
Normal
*
*
p < 0.03
**
*
*
45 degree field
Perceived driving difficulty and other self-restricting behaviors:
Spearman’s r
Low days driving per week -0.44**
Limited furthest distance -0.33**
Low weekly mileages -0.29*
Slow speed relative to traffic flow -0.27*
* p = 0.05; ** p =0.01
Bioptic Telescopes
• For people with moderately reduced visual acuity
• Spectacle mounted• Distance spotting• Most of time look
through carrier lens