This essentially means wear and tear affecting one’s vision as they get older.
The macula is an oval-shaped pigmented area near the centre of the retina of the human eye. It has a diameter of around 5mm.
The consequence of a decrease in central vision is that activities that involve motor function (e.g. driving or precisely directed focusing tasks, such as reading) are affected. Faces can be difficult to recognise but there may be sufficient peripheral vision that some daily activities can still be conducted.
At risk groups:
Studies in Singapore have revealed that there is a 2-4 times increased risk of developing AMD in smokers and older people. The risk increases for those over the age of 50.
Other risk factors include:
- Family history
- Being female
- Obesity
- Cardiac or vascular conditions
Clinical features of AMD
There may be rapid or gradual blurring of central visual fields, with missing areas of vision (all that you can see out of your eyes are called the visual fields, which become disturbed - the straight lines of grids, such as in trelliswork, may appear to bend or to have blank spaces for parts of the grid).
Colour differentiation may also become a problem, and the time taken for your vision to recover from an intense light being shone into your eyes may take a lot longer. Being able to interpret differential shading becomes an increasing problem as more of the macular is affected.
Types of AMD
There are ‘wet’ and ‘dry’ forms of AMD. The majority of AMD are the dry form, in which there is degeneration and death of the light receptors cells.
The pathology seen in ‘wet’ AMD is due to abnormal blood vessel growth, where frail capillaries lead to blood moving across the blood vessel wall into the retina causing visual loss. The rate of visual loss with wet AMD tends to be faster than the dry form.
Treatment of AMD
For ‘wet’ AMD:
There are a number of treatments where the success depends on when the condition is recognised. The options that are available include:
- Drugs injected to slow or stop abnormal blood vessel development
- Laser photocoagulation – used to seal and destroy abnormal blood vessels
- Photodynamic therapy with an intravenous being given
For ‘dry’ AMD:
The therapy is directed towards assisting the use of peripheral vision, eg enlarging lens and other visual enhancing devices. This is usually a progressive slower condition than wet AMD; however, about 1 in 10 lead to the more aggressive wet form.
There is some suggestion that eating your greens (truly!) might help.
Prevention
- Stopping smoking
- Balanced diet with fruit and green vegetables
- Keeping within recommended alcohol weekly amounts
- Staying in good health
MEDICO-LEGAL ASPECTS
Delay in the diagnosis can impact on one’s occupation and also the functional capabilities of many everyday activities such as driving and reading.
Patients may present a number of times before diagnosis is made. Routine eye screening should be offered to patients particularly if any of the symptoms are presented to the GP.
Optometrists may also refer such patients from routine screening to the GP who must take this seriously and go on to manage the condition actively.
If you want further information about this particular topic, or wish to discuss the possibility of bringing a claim for Clinical Negligence - or indeed any other type of injury, please contact the Dutton Gregory Clinical Negligence Team on (01202) 315005, or email k.marden@duttongregory.co.uk
NB This article does not constitute legal advice and should not be relied on as such. No responsibility for the accuracy and/or correctness of the information and commentary set out in the article, or for any consequences of relying on it, is assumed or accepted by any member of Dutton Gregory LLP.
