Pat Sidley
SOUTH AFRICAN wearers of disposable soft contact lenses=20 are at risk from a rare but devastating condition which=20 can lead to blindness.
The condition is caused by an organism carried in water=20 (including tap water), dust or air, and it causes a=20 disorder called Acanthamoeba keratitis.
Although uncommon, sufferers can go blind or will need=20 corneal transplants. But with greater care by users,=20 and more education by optometrists, 80 percent of the=20 occurrence of this disease could be prevented.
A recent edition of the British Medical Journal (BMJ)=20 carries a study from data collected at London’s=20 Moorfields Hospital which shows a significant increase=20 in the incidence of the disease among people who wear=20 soft contact lenses — especially disposables.
In South Africa about 210 000 people wear soft contact=20 lenses and of those about 60 percent wear disposables.
Preparations available for cleaning and disinfecting=20 lenses do not contain easily to understand information=20 for consumers to discern which to use, and few have=20 been tested for their ability to kill the amoeba which=20 causes the disease. Pharmacies, where most are sold=20 have no extra information either. Local optometrists=20 believe it “confuses consumers” to give too much=20
The BMJ article says the increase in the condition is=20 caused by inadequate measures taken to disinfect=20 disposable lenses. Some preparations do not kill the=20
According to Zena Jacobson, who is on the executive of=20 the South African Optometric Association as well as=20 president of the South African Contact Lens Society,=20 too much detail is problematic for patients, many of=20 whom neglect to do what they have been told. She says,=20 however, that the association is busy educating its=20 members on these issues.
However, Grant Jenkins, a respected lens practitioner=20 who lectures to university students on the topic and is=20 a clinical consultant for Johnson and Johnson (the=20 major suppliers of disposable lenses), says all=20 optometrists were issued with a full “position paper”,=20 in both 1991 and 1994, which give careful guidelines.
He said the BMJ article was controversial, and there=20 had only been eight cases in this country.
A Johannesburg ophthalmologist said although the=20 condition was uncommon, it was around more frequently.=20 He had not had to treat the condition, but knew of a=20 victim who had to have both corneas transplanted.
These points for consumers were made by several of the=20 experts contacted:
* Consult an adequately qualified and recommended=20 practioner. Check that she/he follows the position=20 paper set out by the Optometric Association.
* Follow what the practioner states about the lenses=20 he has prescribed
* There are several different types of disposable=20 contact lenses. Check that the instructions given are=20 for the type of lens prescribed. Some use a multi- purpose cleaner only, others require a regime using=20 three different solutions.
* Never use an unsterilised saline solution
* Keep away from chlorine-based systems
* Do not use tap water (or swimming pool or river=20 water) on the lens
* Keep the lens case clean
* Do not use expired solutions