Whats the most important thing you probably dont know regarding your low vision patients who want to drive?

Your own states law.

To find out, call your state capital and ask for regulations on driver safety, says optometrist Richard J. Shuldiner, a low vision specialist who practices throughout Southern California.

Dr. Shuldiner, who teaches continuing education courses on driving and low vision, has compiled a comprehensive list of the driving rules in different states. Still, he suggests that you check the regulations in your own state for the most up-to-date, comprehensive information. So, when a patient walks in and says he wants to drive, you at least know the requirements, he says.

Visual Acuity ≠ Driving Ability
Dont confuse satisfying the visual acuity requirement with competence to operate a motor vehicle, says optometrist Eli Peli, senior scientist in aging eye research at the Schepens Eye Research Institute and professor of ophthalmology at Harvard Medical School. Dr. Peli is co-author of the book, Driving with Confidence: A Practical Guide to Driving with Low Vision (World Scientific, 2002).

Its not practical, and maybe not possible, to determine if a person can drive just from sitting in the exam chair, Dr. Peli says.

Visual acuity and visual field, although important, arent the only factors that play into a patients ability to drive. A person could satisfy the states requirements but not be safe to drive, Dr. Peli says.

 To that end, ask questions about driving when you take the patients history, says Richard L. Windsor, O.D., of the Low Vision Centers of Indiana. Questions about driving are especially crucial among elderly patients and patients with visual impairment. They should include:

How frequently do you drive?

Do you drive at night?

Have you had any accidents?

Have you had any driving violations or parking tickets?

Following this, you can perform some simple tests as part of the evaluation. For example, a patient with age-related macular degeneration may see 20/40, which would allow her to pass the states vision requirement. But that patient may have poor glare recovery on a photostress test, Dr. Windsor says.

Likewise, a patient may have acceptable visual acuity but cognitive limitations, such as early Alzheimers disease or traumatic brain injury. For such patients, Dr. Windsor administers a computer-aided useful field of view (UFOV) test. (UFOV is the area from which one can extract visual information in a brief glance without head or eye movements, Dr. Windsor says.)

Also consider the patients physical limitations. A patient with severe arthritis in the neck, for example, may see 20/20 but have trouble looking into the rear-view mirror.

The point is, we should look at each persons ability and their potential, and evaluate that against their [driving] needs, he says.

In most states, patients who have limitationssuch as those with diplopia or homonymous hemianopsia, for instancecan return to driving, albeit with a modified license, Dr. Windsor says. Low vision patients can undergo driver training and be fit with a bioptic telescope, or they can drive under certain specific conditions, such as during daytime only.

Your Duty to Report

Optometrists are required to report deficient drivers in only two states: Oregon and Pennsylvania, says optometrist and attorney Robert E. Dister, a specialist in legal issues of low vision and an associate clinical professor at the University of California, Berkeley, School of Optometry.

For O.D.s in the other 48 states, choose what you think serves the greater good, Dr. Dister says. Realize that doctors are rarely, if ever, penalized for reporting a patient who may pose a danger to himself and/or others.

His advice: Dont approach a patient as if you need to take away his license. Instead, counsel the patient about his visual limitations and how these limitations can affect his driving. The photostress test, for example, can make a convincing demonstration to patients of their vision and driving ability (or lack thereof). Include family members in the discussion, if possible.

For a good resource on how to counsel borderline patients, Dr. Dister says, download the Physicians Guide to Assessing and Counseling Older Drivers, developed by the American Medical Association and the National Highway Traffic Safety Administration (www.ama-assn.org/ama/pub/category/10791.html.)

If you dont want to be the bad guy, or even if you just want to get a better handle on the patients ability to drive, refer the patient to a low vision specialist or to a driving rehabilitation specialist for a behind-the-wheel evaluation, Dr. Windsor suggests. (To locate a driving rehabilitation specialist, go to the Web site of the Association for Driver Rehabilitation Specialists: www.aded.net/custom/directory.) 

Vol. No: 142:2Issue: 2/15/05