New Contacts, Old Infections. Warning for extended wear contacts!

Discussion in 'Contact Lenses' started by acemanvx, Jul 21, 2006.

  1. acemanvx

    acemanvx Guest

    The newest extended-wear contact lenses have a similar risk of eye
    infections as older soft lenses worn for fewer nights.

    That news is reported in Ophthalmology. It comes from postmarketing
    studies funded by CIBA Vision, which makes the silicone hydrogel
    lenses, marketed as Night & Day.

    The researchers included Oliver Schein, MD, MPH, of Johns Hopkins
    University's medical school.

    Lenses' History

    The FDA approved the silicone hydrogel lenses in 2001 for continuous
    wear for up to 30 nights.

    Older generations of extended-wear contacts had been associated with
    rare cases of vision loss and eye infections. That prompted the FDA's
    1989 decision to cut extended wear to seven days.

    Years later, silicone hydrogel lenses were developed. Compared with
    older lenses, they allow four times as much oxygen to reach the eye.
    Better oxygen flow was seen as a way to possibly lower infection risk
    in the eye's cornea.

    The FDA ordered postmarketing studies of silicone hydrogel lenses to
    check corneal infection rates.

    Year-Long Study

    The study included 6,245 people who had been given prescriptions for
    the silicone hydrogel lenses. Most (80%) wore their lenses nonstop for
    at least three weeks.

    During the year-long study, few participants had corneal infections.
    Two had corneal infections that led to vision loss. Eight others had
    corneal infections that didn't cause vision loss.

    Overall, the yearly rate of corneal infections was 18 per 10,000
    people, the study shows.

    That's similar to rates previously reported for conventional,
    extended-wear soft lenses worn for fewer consecutive nights, according
    to the researchers.

    Researchers' Pecking Order

    Schein's team calls contact lenses "very safe" in general, though
    they note that contact lenses are associated with some extra risks,
    compared with eyeglasses.

    They rank the risk of vision loss from eye infection for different
    types of contact lenses:

    Lowest risk: Rigid, gas-permeable contact lenses for daily wear

    Next-to-lowest risk: Soft contact lenses for daily wear

    Highest risk: Silicone hydrogel contact lenses for extended wear of
    three-to-four weeks

    However, they're not calling silicone hydrogel lenses dangerous. The
    odds appear "reasonable," write the researchers, for people who
    understand the risks and want to wear their contacts around the clock.

    The study notes that one researcher is a CIBA Vision consultant and one
    is a CIBA Vision employee.

    SOURCES: Schein, O. Ophthalmology, Dec. 2005; vol 112: pp 2172-2179.
    News release, Johns Hopkins University.

    By Miranda Hitti
    Reviewed by Louise Chang, MD
    © 2005, WebMD Inc. All rights reserved.
    acemanvx, Jul 21, 2006
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  2. acemanvx

    Dr. Leukoma Guest

    No. This is not a correct conclusion.

    The incidence of microbial keratitis is much higher in prospective
    studies than it is in retrospective population studies. In
    retrospective population-based studies, the incidence of microbial
    keratitis in conventional hydrogel overnight lens wear is 1/500 per
    year. In a large, multicenter prospective study, the incidence is
    1/210 per year, nearly twice as great. Therefore, one should be
    comparing apples to apples and not apples to oranges, and comparing an
    annual incidence of 1/600 for silicone-hydrogel, vs. 1/210 for
    conventional hydrogel.

    Also, different classification schemes for corneal infiltrates yields
    different results. Some corneal infiltrates are sterile. At the very
    least, silicone-hydrogel lenses are 3 times safer.

    Finally, do not make the erroneous conclusion that overnight RGP lens
    wear is the same as overnight OK lens wear just because the lens
    materials are the same.

    Dr. Leukoma, Jul 21, 2006
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  3. acemanvx

    Sandy Guest


    Extended wear today is much safer than old extended wear for several
    reasons. See
    Sandy, Jul 21, 2006
  4. acemanvx

    acemanvx Guest

    Overnight extend wear lens countinues to spur debate and controversity.
    The biggest reason is because its as quick and easy to pop out your
    contacts before going to bed as its to tie your shoes. I have several
    friends who wear contacts, most dont sleep in them unless they come
    home too drunk to remove the lens that night. They also see no point
    when it takes half a minute to pop them out and near a minute to insert
    them in. Cleaning them is quick and easy thanks to no-rub solvents. It
    is irrevelent how much safer silicone hydrogels are, they are not 100%
    safe for sleeping in. There is NO point sleeping in contacts(except
    orthoK) and whats even worse than sleeping in contacts is leaving them
    on your eyes for 2, 3 even 4 weeks strait. All the dirt and bacteria
    can accumulate when you dont clean your contacts for so long! My own
    optometrist knows this and he also warns patients against extend wear
    contacts reguardless of brand. Some people are stubborn and dumb and
    dont listen to their *doctor* then they pay the price with ruined eyes.
    Before SHCL's many people were ruining their eyes with improper wear of
    hydrogel contacts. They developed infections and uclers and I read the
    story of one woman who was going to need a cornea transplant in one eye
    and her doctor told her she might go legally blind in that eye. All
    because she didnt have the sense or patient to take HALF A MINUTE to
    remove her contacts before bed!
    acemanvx, Jul 22, 2006
  5. acemanvx

    Dr. Leukoma Guest

    Anon E. Muss wrote:
    Is there really any point in debating the issue of overnight wear?
    People who sleep in lenses aren't "lazy," any more than people who get
    LASIK are irresponsible. We know what the risks are, and they are
    reasonably low. In more than 20 years of practice, I have documented
    one patient who suffered a loss of one line of acuity from sleeping in
    a contact lens, and it was an RGP lens at that.

    Silicone hydrogels are only the beginning.

    Dr. Leukoma, Jul 22, 2006
  6. acemanvx

    Pam Gasson Guest

    I have been wearing Ciba Vision Night & Day since they first came out
    and there is no way I would go back to taking lenses out every day.
    If you are long sighted like I am it takes ages trying to get them back
    in even using a strong magnifying mirror.I have very dry eyes and these
    are the only contact lenses I am happy with. The only time I take
    them out is when they have to be changed after a month.I personally
    think the little you have to handle your lenses the better.


    Pam Gasson, Jul 22, 2006
  7. acemanvx

    acemanvx Guest

    I am guilty of some bad habits, almost everyone is. I can see why there
    is a market for EW lenses, its probably to serve those who have been
    sleeping in the older hydrogel lenses which are much worse. However one
    thing I dont like is the way they market those EW lenses as "safe" then
    people who would never think about sleeping in contacts may be under
    the false impression that its perfectly safe with the new EW lenses. I
    understand the issue needs to be addressed, but what should be done is
    perhaps provide a disclaimer for EW lenses so the patient is informed
    or verbally warn about the risks. I am glad my optometrist did or I
    could be sleeping in contacts and wearing them for several weeks strait
    without even knowing how risky that is.

    The less bad habits, the better. Maybe they get lots of enjoyment from
    alcohol but it makes no difference to them if they save a few seconds
    it takes to pop out their lenses if they arent too tired or intoxicated
    to do so.

    There is always glasses they can reach for. If they have a low(er)
    prescription, its not such an emergency. I am in the -4 range and even
    I can do perfectly fine without correction after waking to brush my
    teeth and eat. What can be done is warn them of the risks of sleeping
    in contacts and if they insist on sleeping in them, then the least they
    can do is take them out for cleaning everyday.

    should people be rubbing their contacts? Should they be using a
    different solvent?

    That much ill agree. However wearing contacts for a month strait
    without taking them out increases the risk 20x fold then its not so
    safe at all, in fact there is controversity which is riskier, EW
    contacts or lasik, especially when we look into the long term damage
    each does to one's eyes. There is no excuse to get either, just take
    proper care of your contacts and eyes. Many people who get lasik in
    fact have worn and abused contacts for many years and damaged their
    eyes and/or their eyes have rejected contacts. They could not get used
    to glasses having worn only contacts for many years and also it may be
    a vanity thing. It appears that 75% of those getting lasik are contact
    wearers, nearly all of them with problems with contacts.

    The less nights they sleep in them, the more often they remove and
    clean them, the safer.

    The difference with orthoK is you can remove it when you wake up,
    giving your eyes the chance to breath and you get to see clearly for
    many hours too. OrthoK is great for athlates, pilots, cops, swimmers
    where regular contacts would not be very approperate. Much less risky
    than lasik and less risky than EW contacts in fact. OrthoK can be worn
    8 hours at night every other day. Thats 8 hour orthoK wear out of 48
    hours vs. nonstop wear with EW contacts for a week or more. If someone
    wants good vision, there is natural vision improvement and orthoK, both
    which are far better. Lasik is a last resort choice when none of the
    other options work AND when you have very good reasons why you refuse
    to stick with glasses.

    I dont really have much reason not to stick with glasses. I admit itll
    be nice to reduce dependancy on glasses, but nothing riskier than
    orthoK is worth taking. Most people regret lasik if it backfires on
    them, others just go into denial.
    acemanvx, Jul 22, 2006
  8. acemanvx

    acemanvx Guest

    You are going to ruin your eyes soon. There are tricks to taking them
    out. What you could do is take one contact out, clean it then insert it
    then take out the other one to clean then insert it. You really
    shouldnt be going a month strait without cleaning them! You will have
    problems in a matter of time and may have to go back to glasses.
    acemanvx, Jul 22, 2006
  9. acemanvx

    Dr. Leukoma Guest

    Actually, there are a couple of studies recently published that
    underscore this experience. One studied the adherence of bacteria to
    the surfaces of lotrafilcon A and balafilcon A lenses at 2 and 4 weeks
    of wear. The researchers found that the lotrafilcon A surface was
    initially rougher and less wettable than the balafilcon A surface, but
    that these differences became insignificant after 4 weeks. But,
    lotrafilcon showed decreased adherence of all bacterial strains at 4
    weeks compared to 2. The balafilcon A showed declining adherence of
    pseudomonas a., but an increasing adherence of staph. aureus 835.

    The second bit of evidence is found within the study quoted by our
    resident amateur scientist, "Ace." The rate of presumed microbial
    keratitis was lower for users reporting typical wear of 3 or more weeks
    than for those wearing the lens for less than a 3-week continuous
    period (P = 0.02).

    Dr. Leukoma, Jul 22, 2006
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