PUBLISHED:17:05 EST, 20 August 2012| UPDATED:17:05 EST, 20 August 2012
As a contact lens wearer, Jennie Hurst knew the importance of good hygiene to prevent eye infections.
‘I was meticulous about removing my lenses before bed and making sure I did so with clean hands,’ says the 28-year-old from Southampton.
‘I wore monthlies — where the lenses are removed each night and replaced once a month — but I was so conscious of getting an infection that I replaced them every two weeks.
And I always cleaned them with contact lens cleaning solution, unlike some of my friends who’d run their lenses under the tap or even moisten them with saliva.’
Despite this, Jennie, who works as an environmental co-ordinator, is now blind in her left eye — the result of a vicious infection.
Swimming while wearing her contact lenses, something she never realised put her at risk.
Jennie is one of a growing number of people — the majority of them young — suffering potentially devastating eye infections due to a lack of knowledge of the risks of contact lenses, say experts.
In her case the problem is acanthamoeba keratitis, caused by an amoeba — a parasite found in almost all soil, fresh water and sea water.
It thrives where limescale and bacteria are present, but contact lens wearers are at highest risk if they clean their lenses or lens cases in tap water, or if they swim, shower or bathe while wearing their lenses.
This means the parasite can become trapped between the lens and the eye, allowing it to burrow into the eyeball.
Indeed, Jennie’s problems began after a quick swim in a hotel pool while on a break in the West Country last summer.
‘The irony is that I don’t even like swimming — I only did a few laps,’ says Jennie, who had worn contact lenses for five years at that point.
‘I had no idea of the dangers of swimming in lenses — my biggest concern was simply losing a lens in the pool.
‘I remember getting some water in my eye, but thought nothing of it.
‘Then, three days later, I noticed my left eye was very sensitive to light and felt like it had a chemical irritation.
‘It was a bit red but there wasn’t any discharge like a normal eye infection — I’d had one of those years before, although not from contact lenses.
‘Then, over the next day, the most excruciating pain kicked in, so I drove myself to hospital.’
There, doctors referred her to the specialist eye casualty at Southampton General Hospital, where she was given eye drops and told to return a week later.
‘With no improvement, the doctors explained they’d have to take a scrape of the surface of my eye to see if there was an infection.
‘They also asked if I’d done anything unusual and I said swimming. They said this was the most likely cause, explaining contact lens wearers should never do that with their lenses in.
‘I felt so guilty — if I’d known I’d have whipped them out in seconds and worn my glasses instead.’
The initial scrape of her eye revealed she had acanthamoeba keratitis and this began six months off work for Jennie, who by this point was ‘almost blind’ in that eye.
‘I had my first operation that day — the top layers of my eye were scraped off, and I then administered half hourly drops day and night.
‘The drops, which contained strong chemicals, were really painful. And when you’re having them so often you just don’t sleep.
‘I spent the majority of time in a dark room — even the light on my phone screen was too bright to look at.
‘I was in hospital three times in six months (about two weeks in total) and then had to move in with my parents, as I couldn’t do anything for myself.
‘On the rare occasions I did leave the house, I had to literally follow my Dad’s footsteps because I couldn’t see.’
Even light hitting the good eye would make her bad eye painful, and her vision was blurred due to watery eyes.
It’s estimated that 3.7 million Britons wear contact lenses.
Though rare, acanthamoeba keratitis is an extremely painful, sight-threatening condition.
The organism eats the cornea, the transparent cover of the eye, says Parwez Hossain, the consultant ophthalmologist at Southampton General Hospital’s eye unit who treated Jennie.
Left to burrow, the amoeba can penetrate through the eyeball, causing total vision loss within weeks.
‘The condition is pure torture — the amoeba is attacking the nerves of the cornea — and treatment itself is very painful.
‘It can involve a year of regular and toxic eye drops,’ says Mr Hossain.
‘Jennie has been particularly unlucky — hers is one of the most severe cases I’ve seen.
‘The problem is that people have no idea of the risks of swimming or showering while wearing lenses.’
What’s more, cases are on the rise.
‘At Southampton we have noticed an increase, as have other eye units around the country, perhaps due to a lack of awareness of contact lens hygiene,’ says Mr Hossain.
A letter from doctors at Bristol Eye Hospital to the BMJ last year stated that many acanthamoeba keratitis patients had been washing lenses in tap water and showering or swimming wearing them.
And there are many more common eye infections linked to poor lens hygiene that can have similarly devastating results.
‘Psuedomonas bacteria cause the most common type of infection in contact lens wearers,’ adds Mr Hossain.
‘It’s another bug that lives in water and can destroy your sight within 24-36 hours.
‘A common symptom is green pus and pain, discomfort and light sensitivity after only a few hours.
‘It’s often mistaken for conjunctivitis but, if you have these symptoms, it’s vital to seek medical help, as after two or three days, the cornea may perforate.’
The problem generally occurs with poor hygiene.
‘Even daily disposables are risky if your hands aren’t clean,’ says Mr Hossain.
‘You need to wash hands with soap and water to get rid of bacteria, then dry them on a clean towel.
‘And never run lenses under a tap, as parasites could get onto your lens and into your eye.’
Not changing contact lenses when you’re supposed to is another problem.
But by far the biggest culprit for infections is not replacing your lens case every month.
Over time, cracks in the case can form in which micro-organisms can thrive.
Mr Hossain warns that young people are leaving themselves particularly vulnerable to infections.
‘They tend to be quite relaxed when it comes to the hygiene standards required for wearing contact lenses and that’s reflected in the number of people under 50 being treated for severe cases of corneal infection, with an average age of 30.
‘This, coupled with an explosion of cheap online stores, means the consequences can be grim,’ he explains.
‘An audit we performed at Southampton discovered a number of patients presenting to eye casualty had bought online.’
Keith Tempany, of the British Contact Lens Association, agrees.
‘There is little policing of buying lenses on the internet.
‘Australian research has found you’re five times more likely to get an infection buying this way, as there are fewer reminders about good lens hygiene.
‘When you have a check-up at the opticians they can assess the health of your eyes, ensure you’re changing the case regularly and that you have the right type of lens for your lifestyle.
‘For example, if you do a lot of water sports then orthokeratology is a good option.
‘This is where lenses are worn at night and gently re-shape the cornea to correct myopia (shortsight).’
For Jennie, such advice is too late.
In the past year she has undergone six operations to try to remove the parasite — and is still having treatment to try to regain some vision in the damaged eye.
She is gradually adjusting to her limited sight.
‘I misjudge slopes and uneven pavements are a nightmare.
‘In crowds I’ve accepted I’ll walk into people, as I just don’t see them.
‘The good news is I’m driving again so life is slowly returning to normal.
‘But I consider myself lucky that only one eye was affected.
‘I’d urge contact lens wearers to be extremely careful — I never imagined this could happen from a quick swim.’
Jennie is fundraising for research into eye conditions: Justgiving.com/see-the-light. For contact lens advice visit http://www.bcla.org.uk.