Case study 3: Blurred vision

Myeloproliferative disorders

Visual loss

A 57-year-old man presents to the general practitioner with blurred vision. He subsequently sees an optician who finds some abnormality but does not discuss this with the patient other than sending him to the Eye Hospital. Investigations show that he has chronic myeloid leukaemia and he is treated with leukophoresis or chemotherapy and allopurinol. Other treatment options are discussed. Further issues included in the case are communication about illness and also fund-holding by general practitioners.

• Attribution of causality,
• Visual problems and work,
• Rehabilitation.

Chronic myeloid leukaemia (CML) is a relatively rare cause of blurred vision particularly as a presenting symptom. Treatment details are discussed elsewhere but the blurred vision and the impact of treatment themselves are likely to have profound consequences on an individuals capacity and inclination to work.

The blurred vision, if the causal leukocytosis is suppressed by treatment may be transitory. However the treatment itself is likely to be prolonged, toxic and may have to be phased or repeated. What are the prospects for “normal life” whilst all this is going on?

If you were advising the patient, you might get asked a series of questions like these:

• Can this have been caused by my work with radiation or chemicals?
• I need to go on working but I can't see properly - what shall I do?
• Should I just pack my work in and take ill-health retirement to enjoy what time I've got left?

When you’ve thought about these questions for a bit, jot down some points you would want to make an each issue and then see how that compares with what follows here. You may disagree with what is said. If so, why? It may be that it is possible to disagree about what is in the patient's best interest or alternatively that you simply have strong views on some issue.

Both ionising radiation and some chemicals can cause CML so a simple answer could be 'yes'. The problem with this reply is that you are an "authority figure" and your patient may well accept your throw away comment as having more weight than it was intended to or could have. For ionising radiation, it is possible on a statistical basis to work out a dose-related "causation probability". Few radiation workers now get the doses to produce a high causation probability. Similar arguments, although not easily quantifiable apply to chemical exposures. Also the exposures have to be confirmed and have to have a plausible latency (the time lag between exposure and cancer effect). It's a complicated and specialised area of estimation so don't be authorative without authority!

It's better to say, "It's a possibility that can be explored" or "It's unlikely but there are experts who can advise you".

Blurred vision can be a very alarming symptom and what reassurance can be reasonably offered should be provided clearly.

It is certainly reasonable to wait a little while to see if treatment helps but even early on there may be decisions to take and help to offer. Thus some jobs require specific, tight standards of visual acuity, e.g. Fire-fighters, police and ambulance men; bus and HGV drivers. The DVLA is a mine of information on fitness to drive in all sorts of circumstances, conducts research on the subject and has specialist medical advisers. The medical standards of fitness to drive are published in their At a Glance guide.

More general advice is available from occupational health departments who can help with both temporary adjustments to work as well as longer term overviews or rehabilitation and resources.

As many people now work with display screens, this is a common area where advice may be needed. Look up the Health and Safety Executive's website on the Display Screen Regulations to see what sort of things need to be considered.

It is best to be guarded about this. It depends on a number of factors:

• How ill the treatment makes the patient,
• How long it lasts,
• Whether the condition responds to treatment,
• How onerous the job is,
• Can it be adapted?

Because of all these variables, blanket reassurance is unwise since it is likely to spurious, at least in some cases. It is better to outline some of the variables and explore the nature of the burdens that the individual’s job imposes. An occupational health unit is well used to the complex and prolonged dialogue and alterations to plans that the clinical situation may impose on work capacity and those (colleagues, bosses, etc) affected by it.

You should be familiar with The Equality Act 2010 which can be used as a lever to help your patient. Here is a list of some of the resources that can be called down to help (NB: they can take a lot of organising/fixing between different government and local authority agencies):

• Assisted transport to and from work,
• Motability vehicle,
• Magnifying display screens,
• Enhanced illumination,
• Enhanced workplace access (including wheel chair).

This is just an idea of the scope: each case is different and needs to be dealt with individually.

This is the individual's decision. You should stick to the facts and giving advice about them. The biggest mistake is to promise something you do not have authority over, like ill-health retirement. The second biggest mistake is to push for closure on the work situation prematurely. It may be unpleasant to be feeling ill at work. This can be dealt with by shortening hours or other adjustments. Being stuck at home and unwell and brooding about it can be a lot worse.