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Severe
myopia can be permanently corrected
see as PDF
Procedure implants contact lenses via intra-ocular surgery
By Susannah Benady
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MONTREAL – Training for a new outpatient procedure that
permanently corrects the vision of severely myopic patients is
being offered here to ophthalmologists from Quebec and other
provinces.
Candidates
for the refractive surgery, which involves implanting a
proprietary contact lens, are those for whom myopia is a
disability, said Dr. Sam Fanous, who is teaching the
technique. He is assistant professor of ophthalmology at the
University of Montreal.
Patients with moderate to
severe short sightedness or long-sightedness often cannot
benefit from LASIK surgery because of the amount of correction
needed to the cornea, said Dr. Fanous.
The
implant, a new type of contact lens made from a proprietary
hema co-polymer/porcine collagen placed between the iris and
the natural lens of the eye, can provide 20/40 to 20/20
vision, according to results of a 600-patient North American
trial.
In the clinical trials in Canada
and the United States, 85% of patients achieved 20/40 vision
and better (the standard required for driving without
corrective lenses), and 60% reached as high as 20/20 vision.
"This is a real
breakthrough in refractive surgery," said Dr. Fanous, one of two Canadian
surgeons selected for the trial and the only surgeon in Quebec
practising the new technique.
"The new
technology is also good news for myopic or hyperopic people
with corneas too thin to withstand laser refractive surgery."
Dr. Fanous is offering the training at
the Montreal Eye Clinic, the only clinic in Quebec and one of
only three in Canada licensed by the lens manufacturer STAAR
to train and certify surgeons to do the procedure.
The company will only
supply the new device to surgeons who have been trained
through one of its recognized certification courses, said Dr.
Fanous.
"As far as I am aware, this is the first
time a company has taken the decision to sell a device only to
doctors who have been trained to use it. They won't just sell
it to any doctor."
Dr.
Fanous did the surgery for
one of the first of the more than 600 patients in the study
who had lenses implanted in one or both eyes. Ten U.S.
surgeons also participated in the trial, completed about six
months ago.
To date,
Dr. Fanous has done about 30
of the implants, most during the trials.
He described the surgery as much more
technically difficult than laser surgery.
"This is intra-ocular surgery which is
much more complex than sculpting the surface of the eye as in
laser surgery. We implant the lens inside the eye, so it is a
more delicate technique and requires more training."
The Montreal Eye Clinic held the first
of its monthly training sessions recently for five doctors:
three from Quebec, one from Ontario and one from the
Maritimes.
The two-day sessions begin on
a Sunday with lectures by technical specialists from the
manufacturer on how the lens should be used, patient selection
criteria, possible complications and how to avoid and handle
them.
The surgery is demonstrated the
next day. Trainees also see postoperative patients at various
stages of recovery.
Training doctors
receive their certificate only after they have done their own
first surgery, which must be monitored by the training centre.
"We need to be sure the
surgeon is comfortable with the technique," Dr. Fanous said.
In the practical phase of the training,
surgeons begin by learning to manipulate the lens and practise
insertion.
"We are
operating in a very limited zone," said Dr. Fanous.
"The
most sensitive part is loading the lens into the special
injector that implants the lens inside the eye, rather than
folding and unfolding it," he said.
"The
area we are working in is 2.5 mm deep so the manoeuvres are
very delicate."
For
this reason, Dr. Fanous does
not expect a stampede of surgeons seeking the training.
"As in any branch of surgery, there are
always some very advanced and intricate procedures only a few
doctors will do.
"Some doctors will come
for the training and then decide never to perform the
procedure because the technique is so delicate," he said.
He is nonetheless confident that with
training, surgeons can attain the necessary competence, and
the procedure and the device are safe.
Adverse reactions in the
trial were fewer than 1%, said Dr. Fanous, although none were
reported in his own patients.
"The most
common and the most minor reactions were high intraocular
pressure due to inflammation," he said.
"We do iridotomies to reduce the risk of
elevated pressure after surgery, but inflammation can cause
the holes to close and pressure to rise, but this is easily
correctable with another iridotomy."
The
take-up rate by patients is more difficult to predict.
"For many patients, there are other
options and we are careful to explain those alternatives to
them," he said. "Also, patients have to pay up to $3,000 for
the procedure. It does not come under medicare because it does
not count as medically necessary."
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