Driving with retinopathy
Driving is safe with background retinopathy. There may be a little glare as below
Remember that control of your diabetes is important, and this may mean you are more liable to hypos. Learn how to prevent these and to treat them when they develop. You must be aware of hypos to maintain a driving licence. Frequent hypos mean you legally must stop driving (p 27). Legally you have to stop driving after one serious hypo, and have to reapply for a licence.
You have to be able to read a number plate at 20m (new number plate) 20.5 (old). This is equivalent to reading the 6/12 snellen line in the eye clinic at 5m, with both eyes (equivalent to 6/10) BJO 15. Here is the DVLA website. You must notify the DVLA if you have laser treatment of both eyes, or if you have laser to your one good eye.
This includes maculopathy and pre-proliferative and proliferative retinopathy. Several problems arise:
- Glare is difficulty seeing when the sun or car headlights are shining into your eyes, is a very common problem, even if you have not had laser. Sometimes it may be due to cataracts which can be removed with an operation, but often it is just one of the problems from retinopathy.
- Often the glare is caused by internal reflections in the eye as above. Normally light hits the retina and is absorbed, but with retinal damage a lot of reflections occur, and these cause the glare.
Healthy retina, no glare: light absorbed
Damaged retina, glare: light scattered and reflected
Some people have to stop driving at night, and are unable to drive if the sun is shining directly into their eyes: tinted glasses or sunglasses may be helpful.
With the more severe types of retinopathy and particularly after you have needed a lot of laser glare may be a really severe problem. Try sunglasses, consult your optometrist and ophthalmologist, but if extremely severe you may have to give up driving.
glare from car headlights
glare from the sun
Retinal damage both from the retinopathy and laser can result in parts of your sight being missing:
Minor peripheral field loss, probably legal to drive
Severe central field loss: unsafe and illegal driving
There should not be a significant visual field defect. This is described in more detail here. There must be no defect greater than 3 adjacent missing points on the the Esterman field. There are exceptions if the condition is completely stable, such as burnt out retinopathy, but each 'exceptional' case has to be discussed with the DVLA.
If you have active retinopathy you will no be able to drive if you have more than 3 joined up points missing on the Esterman field, because it would not be safe. Driving and laser techniques for professionals see p126.
If your condition is stable or deteriorating slowly, you may be entitled to a 3 year licence. But if your condition is getting worse and you are having laser, you may only get a 1 year licence.
After lots of laser for diabetic retinopathy, you may notice a lot of glare and poor night vision. Many such people can see safely during the day, but have poor night vision. These patients are often legally allowed to drive as above, but are not safe to drive at night.
This applies to many of my patients...such a patient must not drive if they see poorly, so they would not drive in bad weather, looking into the sun, heavy rain, or in fog. Because they see well in daylight they are safe to drive in daylight.
Patients who have laser have microvascular disease, and this often affects brain function. Such patients should avoid driving fast, and some need to drive on roads they are familiar with, and not on roads they do not know.
Driving field assessment
- Static none progressive defect, and then assessment.
- Have they adapted to field.
- Assessment fitness to drive for medical, telephone number for medics,
Exceptionality, eg hemianopia
- Flexibility in border zone., decide tolerable risk
- People grew up with hemianopia, and may get used to it.
- Clinical confirmation of adapting
- Hemianopia pt 1.2x risk
- Can drive with adaptation, better with training, need on road test
- So hemianopia >> adapt>> on road test