The Impact of Ocular Diseases on Driving: a Prospective Study

Study Overview
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Brief Summary
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The purpose of the study was (1) to determine thresholds for discriminating speed in peripheral fields of patients with dry AMD and (2) to examine the driving skills of licensed drivers with early dry AMD using a driving simulator and to investigate how their healthy counterparts perform on the same driving tasks. We hypothesized that speed discrimination may be better in patients with dry AMD than in healthy control subjects.

Detailed Description
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This observational study has two goals: to establish if patients affected by dry AMD have a different speed discriminating threshold using peripheral vision fields than their healthy counterparts. to determine if the driving skills of AMD and glaucoma patients differ from healthy controls. Two tasks will be used: 1) A speed discrimination test. (Glaucoma patient are not asked to perform this task as it assesses the peripheral visual fields, which is affected by the disease.) 2) A driving simulation session. Participant will undergo both tests on the same day, no later than a month after the initial recruitement visit. For both diseases, patients will be compared to healthy controls matched for age and gender, but also to a younger control group. The latter group was added in order to take into account the normal aging impact on driving skills (visual and cognitive). Our hypothesis is that AMD patient will show a better speed discriminating threshold than matched control and maybe better or equal to the younger control groups. We also hypothesize that driving skills involving peripheric speed awareness, such as passing another car, will be enhanced in the AMD group when compared to glaucoma patients and age-matched control group.

Official Title
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The Impact of Ocular Diseases on Driving: a Prospective Study

Conditions
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Glaucoma, Macular Degeneration

Intervention / Treatment
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* Other: Speed discrimination test
* Behavioral: Driving simulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Best-corrected visual acuity (BCVA) had to be at least 20/50 (6/15). Binocular visual field (VF) should not be less than 120° along the horizontal meridian and 20° above and below the same meridian. Valid driving license Diagnosis of bilateral dry AMD (AMD group) or open-angle glaucoma (glaucoma group) Exclusion Criteria: Diplopia Cognitive impairment Other ocular diseases

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 95 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| AMD controls<br>15 patients with early to intermediate AMD (grade 2-8) were enrolled using the Age-Related Eye Disease Study (AREDS) severity scale for AMD. | Other: Speed discrimination test<br>* The participant has to stare in the middle of two screens, i.e the reference screen and the test screen. Dots are moving from the center to the edge of the screens at different speeds. The participant is forced to determine if the dots of the test screen are moving faster or slower than the reference screen. The test is designed in Psychtoolbox3. Data analyses performed using MATLAB. Two-alternative forced choice paradigm.<br>Behavioral: Driving simulation<br>* 25 km simulated car driving session. The participant is seated in the driver compartment of a real car featuring all the actual components (steering wheel, pedals regulating speed and brakes). He is instructed to respect road regulations as well as safety rules and must perform some driving manoeuvres, such has turning at intersections, stopping when necessary, passing another car, etc. Software Drive 3.0 by Systems Technology Inc., Hawthorne, California, USA. Magnetic head tracker (Flock of Birds, Ascension Technology Corporation, Burlington, Vermont, USA). A fixed-base driving simulator. 2 driving scenarios: a practice (10 minutes) and a main scenario including rural and urban sections (35 minutes).<br>|
| Age-matched controls<br>15 drivers without ocular disease. | Other: Speed discrimination test<br>* The participant has to stare in the middle of two screens, i.e the reference screen and the test screen. Dots are moving from the center to the edge of the screens at different speeds. The participant is forced to determine if the dots of the test screen are moving faster or slower than the reference screen. The test is designed in Psychtoolbox3. Data analyses performed using MATLAB. Two-alternative forced choice paradigm.<br>Behavioral: Driving simulation<br>* 25 km simulated car driving session. The participant is seated in the driver compartment of a real car featuring all the actual components (steering wheel, pedals regulating speed and brakes). He is instructed to respect road regulations as well as safety rules and must perform some driving manoeuvres, such has turning at intersections, stopping when necessary, passing another car, etc. Software Drive 3.0 by Systems Technology Inc., Hawthorne, California, USA. Magnetic head tracker (Flock of Birds, Ascension Technology Corporation, Burlington, Vermont, USA). A fixed-base driving simulator. 2 driving scenarios: a practice (10 minutes) and a main scenario including rural and urban sections (35 minutes).<br>|
| Young controls<br>15 drivers without ocular disease. Between 18 and 25 years old. | Other: Speed discrimination test<br>* The participant has to stare in the middle of two screens, i.e the reference screen and the test screen. Dots are moving from the center to the edge of the screens at different speeds. The participant is forced to determine if the dots of the test screen are moving faster or slower than the reference screen. The test is designed in Psychtoolbox3. Data analyses performed using MATLAB. Two-alternative forced choice paradigm.<br>Behavioral: Driving simulation<br>* 25 km simulated car driving session. The participant is seated in the driver compartment of a real car featuring all the actual components (steering wheel, pedals regulating speed and brakes). He is instructed to respect road regulations as well as safety rules and must perform some driving manoeuvres, such has turning at intersections, stopping when necessary, passing another car, etc. Software Drive 3.0 by Systems Technology Inc., Hawthorne, California, USA. Magnetic head tracker (Flock of Birds, Ascension Technology Corporation, Burlington, Vermont, USA). A fixed-base driving simulator. 2 driving scenarios: a practice (10 minutes) and a main scenario including rural and urban sections (35 minutes).<br>|
| Glaucoma patients<br>15 patients having a Humphrey visual field mean deviation between -10 and -12 (better eye). | Behavioral: Driving simulation<br>* 25 km simulated car driving session. The participant is seated in the driver compartment of a real car featuring all the actual components (steering wheel, pedals regulating speed and brakes). He is instructed to respect road regulations as well as safety rules and must perform some driving manoeuvres, such has turning at intersections, stopping when necessary, passing another car, etc. Software Drive 3.0 by Systems Technology Inc., Hawthorne, California, USA. Magnetic head tracker (Flock of Birds, Ascension Technology Corporation, Burlington, Vermont, USA). A fixed-base driving simulator. 2 driving scenarios: a practice (10 minutes) and a main scenario including rural and urban sections (35 minutes).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Speed discrimination threshold | 75% point is taken as a measure of the discrimination threshold. | Before driving simulation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Driving performance | Probe reaction time task. Speed limits. Respect of traffic safety rules. | After speed discrimination task |