It goes without saying that good vision, including visual acuity (VA) and visual fields (VF), is essential to the safe operation of a motor vehicle. Any marked loss of either will lead to diminished ability to detect another vehicle, pedestrians or warning signs. It may also increase reaction times to potentially hazardous situations.

But when the age-related macular degeneration (AMD) patient in your chair is approaching (or already past) the stage where they no longer meet the visual requirements to hold a driver’s licence, how do you approach this uncomfortable conversation?

WRITER Michelle Hauschild

No Australia-wide licensing scheme exists, and the rules for driver’s licences vary between states, and between the class of licence held – tests for driving buses and trucks are most stringent. Aspects from the Assessing Fitness to Drive,1 national driver medical standards released by Austroads, and approved by Commonwealth, state and territory Transport Ministers, are interspersed in the commentary.

Vitreoretinal specialist and Director of the Retinology Institute, Associate Professor Wilson Heriot, and Associate Professor Meri Vukicevic from La Trobe University’s Discipline of Orthoptics provided mivision with some answers to questions around vision, driving, and AMD.

Q. What are the guidelines for deciding whether a person is fit for purpose for driving?

Assoc Prof Heriot: Firstly, it is really important to understand that the current driving guidelines are not fit for purpose for age-related macular degeneration. Visual acuity is but one component of vision. Snellen acuity is a quantification of black on white figures projected onto the central foveal cone photoreceptors and is limited to 2–3° of visual field (but represented in about 50% of the visual cortex) and is approximately twice the width of your thumbnail at arm’s length.

Visual dysfunction around that central island of high-resolution acuity is not measured, whereas peripheral vision is, such as for glaucoma or diabetics with either a 24-2, 30-2or Esterman binocular field. The zone between central high-resolution acuity and the periphery is not well quantified and not unambiguously incorporated in current driving guidelines. As such, people with perifoveal geographic atrophy (dry AMD) and small areas of reduced paracentral sensitivity are ignored. This is the area that fails for many people with AMD before central acuity is changed.

Unfortunately, too many people use the term ‘vision’ when they simply mean the zone of high acuity, created by the distribution of cone and rod photoreceptors. We are usually unaware of how small this island of high acuity is because our eyes are constantly roving and the brain blends the central high resolution details with the low res peripheral visual information so that ‘everything’ seems sharp.

The restrictions for a loss of peripheral vision from, for example, glaucoma or brain injury/ stroke, are clearly defined, however the guidelines for a partial central scotoma are vague. In the Austroads standards Assessing Fitness to Drive the phrase “a cluster of four or more adjoining points that is either completely or partly within the central 20° area loss consisting of both a single cluster of three adjoining missed points up to and including 20° from fixation, and any additional separate missed point(s) within the central 20° area” does not define if this test is on a 24-2, 30-2, Esterman or binocular roving Esterman. As such, assessing fitness to drive in the presence of even advanced AMD is up to the clinician.

In practical terms, I often perform macular integrity assessment (MAIA) microperimetry to get an objective assessment of the extent of the central scotoma. The problem with this is that the guideline’s “missing points” on an Esterman do not correlate well with the size of a central scotoma that should “fail the test”.

Despite the above ‘dispassionate’ statement of facts, it is extremely disturbing to have to inform the patient that they cannot drive because they do not satisfy the requirements.

Sometimes it is very clear-cut, but in a number of cases it’s been a gradual evolution of their geographic atrophy and the acuity drifts beyond 6/12. I have to say that, personally, I often opt out of giving a definitive ‘you must stop’ and inform them that they do not currently satisfy the requirements for an unrestricted licence and that hopefully a refraction review by their optometrist (and occasionally undergoing cataract surgery) will restore their acuity to an adequate level.

Hopefully, this is a transition for them to start thinking seriously about making the adjustment to not driving, rather than it being a bold ‘out of the blue’ statement on the day that they cannot even drive themselves home!

If, after a review refraction, they are less than 6/12, it is a matter of determining if they are better than 6/24, such that they could be eligible for a ‘restricted’ licence. In Victoria, the option for a restricted licence exists at the discretion of the doctor, with oversight of the medical advisory committee, for people who are borderline to potentially be allowed to continue to drive with restrictions (such as within a limited distance from home or only in daylight hours). Often this is adequate for their needs to go shopping etc. Many people with AMD realise their vision is not that good in the dark and choose to avoid nighttime driving anyway.

An important point to make is that in some states there is a legal obligation for medical doctors and optometrists to report a failure to pass the visual requirements to maintain a driver’s licence.

Most patients assume that a licence in their wallet is valid until formally discontinued, but the requirements are that one must continue to satisfy all the requirements, as they did when they first obtained their licence to drive.

In addition, patients are required to notify the licence authority of their medical condition (as do diabetics), and also their insurer.

This is critical because most – if not all – car insurance is null and void if the driver is driving unlicensed. This is obvious in the example of a 16-year-old child who has stolen a car but not obvious to older patients with AMD that have driven for 60 years. This can come as a dramatic shock to patients.

This discussion is best done if a family has come to the consultation with them. It is important that the patient and, indirectly, the carer (if present) be informed of the legal implications, even if the patient is reluctant to stop driving because it can be a financial disaster paying for both their own car repairs and those of the other party, irrespective of fault. I have found that family members are very receptive to understanding the financial implications if the patient is not covered by their car insurance.

The border zone between ticking the option to limit drivers’ options and referring to the medical committee is poorly defined and makes for a stressful discussion with the patient.

A practical problem – at least in Victoria – is that patients who are legally blind are able to obtain half-price taxi vouchers, which helps with their mobility. Unfortunately, many patients with AMD have a ‘keyhole’ of that tiny few degrees that can read the Snellen chart but their perifoveal geographic atrophy severely limits their visual function, and thus they are technically ineligible for taxi vouchers.

This is one of the examples of how driving vision criteria are not fit for purpose for this significantly large subgroup of the population. Glaucoma patients have clearly defined criteria but patients with AMD do not – yet.

CRITERIA FOR DRIVING VISION

Assessing Fitness to Drive states that visual acuity (without glasses) of at least 6/12 is required in one or both eyes for an unconditional private driving licence. If corrected visual acuity in the better eye is at least 6/24, then a conditional driver’s licence may be issued.

On central field loss, the Austroads standards outline that “scattered single missed points or a single cluster of up to three adjoining points is acceptable central field loss for a person to hold an unconditional licence”.

“A significant or unacceptable central field loss is defined as any of the following:

• A cluster of four or more adjoining points that is either completely or partly within the central 20° area,

• Loss consisting of both a single cluster of three adjoining missed points up to and including 20° from fixation, and any additional separate missed point(s) within the central 20° area,

• Any central loss that is an extension of a hemianopia or quadrantanopia of size greater than three missed points.”

Assessment to Drive notes that “methods of measuring visual fields are limited in their ability to resemble the demands of the realworld driving environment where drivers are free to move their eyes as required and must sustain their visual function in variable conditions”. Additional factors that can be considered when assessing patients with defects in visual fields include:

• Kinetic fields conducted on a Goldman,

• Binocular Esterman visual fields conducted without fixation monitoring,

• Contrast sensitivity and glare susceptibility,

• Medical history, duration and prognosis, rate of progression, and effectiveness of treatment/management,

• Driving record, and

• The nature of the driving task – for example, roads and distances to be travelled and concomitant medical conditions.1

Q: What should eye health professionals do if they believe a patient is not fit to drive anymore due to vision loss?

Assoc Prof Heriot: Inform the patient and explain specifically which criteria for driving the patient does not meet. As above, dealing with this sensitively is important but it is also important to communicate the legal obligations and the car insurance implications while offering hope, where possible, that some treatment will restore their vision adequately.

In the context of AMD, I advise them that their vision is likely to continue to deteriorate, so that it is only a matter of time, and they should start thinking about making preparations for the inevitable. Where possible, I try to advise them when they are 6/12 that they are heading in the direction of losing their licence. This flags the possibility and prevents the shock of a sudden announcement when it happens.

Q: Do you have any tips on how to raise and explain this delicate news with patients? Is there anything eye health professionals should do, or avoid doing, during a conversation that must be traumatic for some patients?

Assoc Prof Vukicevic: As Assoc Prof Heriot has highlighted, this is a very difficult conversation but sometimes I think giving patients a scenario explaining the type of thing they might miss on the road (a child, a dog, etc.) and the potential to cause serious injury, is effective in helping them understand why good vision is essential for driving. However, many insist that because they have been driving for 60 years, they are safe!

Q: How do you raise this advice with their family/carer?

Assoc Prof Heriot: This is sometimes ‘easy’ in the context of AMD, because family members are already concerned about their elderly parents driving and they just need the tools to reinforce the legal requirements etc. They often offer to overcome practical requirements by taking them shopping, etc. It is very uncommon in my experience to find that the family object, but sometimes it can be unpleasant, that’s for sure.

Q: How do you manage people who are resistant to the advice?

Assoc Prof Heriot: This is obviously a major potential problem because, as my colleague mentioned, many AMD patients feel they have been driving for a long time and therefore they are ‘safe’.

We have no option but to fulfil our legal requirement, even if the patient doesn’t selfreport. This is not obligatory in all states.

All one can do is highlight that it is not legal to continue to drive and provide written documentation of that advice (to cover ourselves). Finally, I would simply complete the notification to the relevant licensing authority (in my case, VicRoads) and leave it to that authority to announce to the patient that their licence to drive has been revoked.

This is an extreme and very uncommon scenario, but that is the backup.

Obviously with current privacy laws, one cannot pick up the phone, call the patient’s relatives, and explain the situation to them without a patient’s consent.

Fortunately, this scenario is extremely rare, in my experience.

Q: Generally, at what point in visual acuity do you recommend people stop driving?

Assoc Prof Vukicevic: Technically, this should be as soon as their vision is less than 6/12 in both eyes. However, depending on the circumstances, if their vision is a bit below 6/12 and they formally don’t comply with the conditions for a full licence, it may be possible to continue driving with restrictions in place if the acuity is at least 6/24 so that they are covered from an insurance/legal point of view.

However, this is partly dependent on the patient’s insight into their own abilities, and the location of the lesions (although that is a subjective assessment of the potential impact of the scotoma in the presence of good acuity).

CONDITIONAL LICENCES

Assessing Fitness to Drive notes that a conditional licence “provides a mechanism for optimising driver and public safety while maintaining driver independence” when a driver has a long-term or progressive health condition.

Examples of a conditional licence could include no night driving, only driving in familiar areas (local area restriction) or having to wear corrective lenses.

A conditional licence identifies the need for medical treatments and may specify a review period.

“A conditional licence therefore offers an alternative to withdrawing a licence and enables individual case-based decision making. Some discretion is allowed in application of the standard by the treating optometrist or ophthalmologist.”

While the driver licensing authority makes the final decision on whether an individual is eligible for a conditional licence, health professionals must advise on which medical requirements have not been met, the likely adequacy of treatments, and plans to monitor and review the medical condition. If appropriate, the health professional can provide information on possible licence conditions, such as radius restriction or no night driving.1

Q: What aspects of macular degeneration make driving particularly challenging?

Assoc Prof Vukicevic: Obviously, insufficient detail to read road signs and identify pedestrians or road hazards is a big issue in terms of visual acuity. Aspects such as reduced dark adaptation become a big issue when driving at night with glare from headlights or streetlights. The much greater contrast between the lit area and the poorly lit area means that things can be missed ‘in the dark’. Because of reduced dark adaptation, moving from brightly lit areas to poorly lit areas – such as through tunnels, or heavily shaded streets – can reduce the ability to respond quickly to an object on the road in a poorly lit area, for example. This is true even for cases with intermediate AMD.

NOTIFYING OTHER HEALTHCARE PROVIDERS

Q: Do eye specialists need to notify the patient’s other healthcare providers (e.g. their GP) after you’ve advised them that they must stop driving?

Assoc Prof Vukicevic: As a courtesy, it is sensible, assuming that the patient has authorised the eye care professional to notify the GP.

Q: Do eye specialists need to put advice about driving in writing to their patient?

Assoc Prof Heriot: If notifying the patient that they do not satisfy the legal requirements for driver’s licence, the answer is yes.

It is also necessary to document in our records that we have informed the patient that they cannot continue to drive and, as they are unlicenced, they are thus uninsured.

Q: What advice or support do you recommend to patients to help them with the transition to a life without driving?

Assoc Prof Vukicevic: Eye Connect from Macular Disease Foundation Australia (MDFA) can help provide support and practical advice, tailored to an individual’s specific needs. It is a national programme that’s available free to anyone at any stage of AMD.

Vision Australia can also provide useful advice, including access to some of the low vision support services.

Dr Meri Vukicevic is an Associate Professor and Course Coordinator in the Discipline of Orthoptics, School of Allied Health, Human Services, and Sport at La Trobe University. Her teaching focus includes ocular anatomy and physiology, eye disease, and clinical investigations. Her research projects are focussed on various aspects of retinal diseases (namely AMD and diabetic eye disease) and, more recently, on driving.

Associate Professor Wilson Heriot is a vitreoretinal specialist based in Melbourne, and the director of Retinology Institute. After completing his general ophthalmic training in Melbourne, he investigated phototoxic retinal injury and choroidal neovascularisation during a two-year medical retinal research fellowship in New York. This was followed by a vitreoretinal surgical fellowship at Duke University.

His current research projects include a translation to clinical care programme for a new method of retinal detachment repair called retinal thermofusion, funded by a United States Department of Defence award.

Assoc Prof Heriot is also a principal investigator for a number of local and international clinical trials in areas of retinal detachment, diabetic retinopathy, and age-related macular degeneration.

Reference

1. Austroads, Assessing Fitness to Drive. 2022. Available at: https://next.magloft.app/collections/mivision-2691/tackling-the-tough-conversation?fullscreen=true [accessed March 2025].