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