BBC London LASER EYE SURGERY Watchdog Healthcheck 12.07.99
New scientific research from Germany shows that seven out of ten patients
are left with defective vision after laser surgery. Poor night vision, nyctalopia,
is caused by the eyes inability to respond quickly enough to changing levels
of light, causing glare, ghosting, halos and starbursts. This is corrected
in most patients by glasses. However, if you've had laser surgery, the condition
may be untreatable.
At Hertfordshire Police HQ, Louise Mahon answers 999 calls. She wanted
to be a policewoman but her eyesight wasn't good enough. Louise hoped laser
surgery would get her in to the Police Force but, by the time she had the
procedure, it was too late. The Home Office had issued new guidelines that
no one who has had laser surgery should join the police. It is not just
the Police Force who have adopted these rules. The Fire Brigade, Lifeboat
Service and the Civil Aviation Authority have also decided not to recruit
laser eye patients. The CAA says "laser procedures may produce side
effects of glare and distortion of vision .... the long- term effects are
unknown and laser surgery is not recommended for aircrew."
Consultant ophthalmologist, William Jory, also has reservations. He used
to perform laser surgery until he heard worrying research presented at international
scientific meetings. He says: "I have been able to demonstrate a loss
of night vision in my laser cases, not all of them but a majority, approximately
80 per cent." When the reports of night vision loss were confirmed
William Jory stopped using the laser for the treatment of shortsight.
In Germany if you have a car accident at night, you may be required to
sit a night vision test. If you fail it, under German law, you'll be held
responsible for the accident. The experimental ophthalmology department
at the University of Tubingen Eye Hospital has been carrying out tests on
post-operative laser patients for nearly 10 years. Its latest findings show
that, despite improvements in technology, over 70 % of patients are still
failing the contrast test . This means it is difficult to make out objects
at night, and 50% are failing what's known as the mesometre test. That means
under Germany law they are unfit to drive.
In Britain there's no night vision test for drivers, so Healthcheck brought
people who've had laser surgery to the Transport Research Laboratory in
Berkshire for sight and driving tests. Our volunteers took two simple sight
tests. First the contrast test - a variation on the traditional sight test,
except it measures how well you can pick out objects in the dark. With good
night vision you should see 9 lines of letters. If your night vision is
poor, you'll have difficulty with the last few lines, and that means your
night vision is affected. Optometrist Nigel Burnett Hod found that most
of our volunteers had problems with those bottom lines. For Healthcheck
he devised a special glare test. He found that, among nine people that represent
a successful group of laser patients, two thirds of them do have slight
night vision problems - a little bit of flare, glare and hazing. So what
was their driving like after midnight on a rural road? The volunteers had
to read two signs. Drivers who'd not had laser surgery read them at 55 metres.
But four out of five who'd had the surgery scored much worse. In line with
German research, most of those we tested had defective night vision. It
may have been poor before surgery, but the lasers hadn't corrected it. In
some jobs and road situations, poor night vision could be disastrous. For
more information and advice, you can contact the RNIB on 0870 010 7070.
Molti corpi: aviazione, polizia , pompieri non accettano
più persone che abbiano subito operazioni. Queste persone hanno una
visione notturna particolarmente cattiva e inadatta alla guida e altre attività.
Le operazioni creano nuovi fenomeni di abbagliamento e perdita di contrasto.
Per continuare a documentarsi
Prima di tutto, se non l'hai ancora letto, vai a Tutto sulle operazioni (Laser: luci ed ombre).
Documentazione (ingl) Introduciamo alcuni articoli forniti da Pietro Gheller, un insegnante
di optometria di Bologna (trovate i suoi indirizzi negli Indirizzi
utili), non facili da leggere, ma importanti.
Due Testimonianze Personali
in italiano, dalla corrispondenza di Buena Vista. Cosa accade quindici giorni
dopo l'operazione, due mesi dopo e tre mesi dopo.
Un sito molto utile: www.malavista.it
Corsi e seminari Holiday on Eyes & DolceVita Indirizzi utili Le
Newsletter Articoli e dispense Bibliografia Rasterbrille Laser: luci ed ombre Testimonianza