Diabetic retinopathy and nephropathy, and their impact in driving

Home > Education and outreach > Road Safety Programs > Safe and healthy mobility > Clinical Topics and Safe Driving > Metabolism and Digestive Disorders Exam > Diabetic retinopathy and nephropathy, and their impact in driving

The risks of a late clinical complication are variable in the different diabetic patients, but they generally appear with the progression of the disease over time.

Hyperglycemia causes the initial metabolic disorders and the first functional disorders in the kidney, peripheral nerves, and retina.

Atherosclerotic arterial disease with angina or myocardial infarction, and peripheral arterial disease with intermittent claudication, ulcers, and gangrene of the legs are more frequent in diabetic patients and appear at an earlier age that in non-diabetics.

Diabetic retinopathy

Diabetic retinopathy causes 70% to 80% of blindness in diabetic patients, and it is more related to the duration of diabetes that to stability.

It is estimated that the possibility that a diabetic person can lose his sight is between 20 and 40 times higher than in the rest of the population.

The initial retinal disorders do not affect significantly vision, but can require immediate treatment in order to prevent complications including macular edema or proliferative retinopathy with bleeding or retinal detachment.

The appearance of visual symptoms, particularly blurred vision, sudden loss of vision in one or both eyes, black spots, and floating bodies or photopsies in the visual field warn about the retinal complications in diabetes, and a visit to the ophthalmologist should be immediate.

Non-proliferative retinopathy is characterized by increased capillary permeability, microaneurysms, bleeding, effusion, and edema. The proliferative occurs as the formation of neovessels and fibrosis, that can eventually cause retinal detachment or vitreous bleeding.

Advice on Diabetic retinopathy

  • The diabetic driver should be warned that, if he starts to notice visual symptoms, particularly blurred vision, sudden loss of vision in one or both eyes and black spots, floating bodies, or photopsies in the visual field, a visit to the ophthalmologist should be immediate.
  • The ophthalmologist, with the accurate diagnosis of the problem, will prescribe care and treatment to cure and prevent injuries, and will report on the capacity of the patient to drive at each time.
  • In general, diabetic drivers with visual problems should avoid driving at night, at dawn and at nightfall.
  • The expert with the accurate diagnosis of the problem will prescribe the care and the treatment cure and prevent injuries, and will report on the ability of the patient to drive at each time.
  • Accordingly, the ophthalmologic review should be half-yearly or annual depending on the progression and control of the disease, and the patient should know it.
  • The medical report with the progression of clinical diabetes should be provided by the patient for obtaining the driving license and extension.
  • Diabetic retinopathy reducing visual capacity below the limits established by the law preventing from driving.

Diabetic nephropathy

It is a frequent cause of nephrotic syndrome (NS), characterized by hypertension, proteinuria, bacteriuria, hyperazotemia, with edema and hyperlipidemia and progression to renal failure.

The urea increase can cause malaise, anorexia, laxity, fatigue, vomiting, and reduction of mental acuity.

In advanced phases, diet salt is retained and hypertension occurs with volume overload and congestive heart failure and edema.

Diabetic patients with advanced CRF had a reduction in the needs for insulin, with risk of serious hypoglycemia if the dose is not adjusted.

Diabetic retinopathy is associated with the progression of nephropathy.

Advice on Diabetic nephropathy

  • Patients with nephrotic syndrome secondary to diabetes mellitus should not drive until the causal disease is adequately treated with a favorable evolution and without increased risks for driving.
  • Patients with NS can show symptoms of their disease that are disabling for driving, such as hypertension difficult to control, progressive loss of renal function, edema, venous thrombosis, etc.
  • The physician should advise against driving in all clinical situations associated with advanced renal failure, or added complications.
  • The first signs of uremia such as laxity, fatigue, and reduced mental acuity diminish the capacity for driving, so it is not recommended until the specialist, with the appropriate treatment and favorable evolution of the patient, decides that the patient can drive safely.
  • The patient cannot drive with uncontrolled hypertension or that can lead to congestive heart failure and edema of the leg.
  • The stable patient with CRF with few symptoms can show acute metabolic or circulatory decompensation due to an intercurrent disease, and impair suddenly. The patient cannot drive until he is stabilized and asymptomatic.
  • The patient with diabetic nephropathy with adjustment of the insulin dose with the progression of renal failure can suffer serious episodes of hypoglycemia that, if occurring while driving, can lead to losing of control of the car.
  • Physicians should warn to all drivers with renal failure, that many drugs can cause side effects that interfere with driving, if the dosage is not adjusted. In it is the case of anxiolytics, antidepressants, anticonvulsants, etc.
  • Drivers with uncontrolled psychological and depressive disorders should be advised not to drive until the favorable outcome of this mood situation is shown.