SCMP Monday, July 23, 2001
Lenses injured 200, survey finds
PATSY MOY and MICHELLE CHAK
Private clinics have treated about 200 patients for eye injuries associated with controversial Ortho-K corrective lenses, a survey found.
The telephone survey of 43 private ophthalmologists by the Association of Practising Private Eye Surgeons found about 200 people had been diagnosed with eye injuries after using the lenses to correct short-sightedness, association president Dr Joseph Kam Ting-kwong said.
The 200 were among 467 people who have sought consultations after using the Ortho-K - short for Orthokeratology - contact lenses since they were introduced in Hong Kong three years ago.
Dr Kam and fellow association member Dr Chow Pak-chin found the injury rate alarming, as an estimated 3,000 people had used the lenses over three years.
Any certified optometrist can prescribe the lenses and there is no government plan to regulate their use.
Dr Chow said: "We have a duty to tell the public our findings to avoid further possible harm to children and young people."
The March survey, which recorded the number of eyes rather than patients, found 157 eyes had suffered abrasions, 100 infection and inflammation, and 14 suffered permanent corneal scars. Three eyes required hospital treatment.
Dr Kam said the number of eyes treated was roughly equivalent to about 200 patients. About 260 others in the survey did not suffer injuries but complained of minor irritation or were simply worried about the lenses. He said the figures could be higher because some patients would have made appointments at public clinics and hospitals.
The Association of Practising Private Eye Surgeons represents 50 ophthalmologists out of about 70 in private practice in the SAR.
The association's concerns were shared by Dr Alfred Leung Tai-shing, professor of ophthalmology at Chinese University.
"No established scientific findings or recognised medical documents so far have shown the product to be effective and safe on children," said Dr Leung, chief of service at Prince of Wales Hospital's eye unit. The hospital called a press conference last month to warn against possible dangers associated with the technique and Dr Leung has called for government control on the use of Ortho-K lenses.
The Hong Kong Orthokeratology Association, which promotes the lenses, argues they are safe, and Associate Professor Pauline Cho-Wong Hie-hua of the Polytechnic University's optometry department says she does not believe all the reports about eye injuries from the procedure. The university is internally funding a $2 million project to study the safety and effectiveness of the technique.
An association statement said: "The lens is working as it is worn, whether you are sleeping or awake. The procedure takes hours to a few months to reach good functional vision. At that point, the lens-wearing time is gradually reduced until a minimal-wear time is achieved."
Professor Cho-Wong said the reported eye injures might be caused by eye doctors themselves who "did not know much", but gave "improper treatment" to patients.
"I would need to see the children and check their eyes with tissue culture. And if there isn't any fault on their part, why haven't any of them sued the optometrist? I reiterate that no such procedures are risk-free," he said.
The Department of Health said it had no plan to regulate the procedure at the moment.
However, it issued general advice more than a week ago warning people to consult qualified ophthalmologists or optometrists before using the lenses, and to take them out and consult professionals immediately if they experienced discomfort.
Bonnie Wan Kwok-ling, manager of the Hong Kong branch of Driemlens, a major US lens manufacturer, said she was against regulation and that special training was not a safety guarantee.
"Optometrists need practice to learn to fit the lenses properly. You can't expect them to fit well at once. We can't refuse any business and it's impossible to make sure only qualified optometrists can get the lenses," she said.
Danny Fan Siu-keung, general manager of Opticraft Ltd which makes the lens, said regulation could not guarantee freedom from mistakes and carelessness.