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LASIK
Eye Surgery Information to help the
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Giant papillary conjunctivitis is an allergic type of inflammation that occurs on the inner surfaces of your eyelids, the "tarsal conjunctiva." It occurs most often in patients who have been wearing lenses for some number of years and who have not used the utmost in care in keeping their lenses clean. The buildup of protein on the contact lens surfaces causes an inflammatory process to occur whereby your lenses become itchy and your eyes actually begin to produce even more protein and mucous than normal. These secretions then cause even more irritation, itching and discomfort, ultimately causing you to have to stop wearing your contact lenses. There are anti-inflammatory and anti-allergic drops that can be prescribed by your eye care professional in order to alleviate the symptoms. However, even after using these drops and getting new contact lenses, and being absolutely meticulous in their care and wearing schedule, some patients are just unable to resume contact lens wear. While the complication of Giant Papillary Conjunctivitis is not sight threatening, it is inconvenient and troubling to those who desire the convenience, cosmetic and functional benefits that contact lenses can offer.
Contact lens induced dry eye occurs in some patients who may have had a
marginally dry eye before they were fit with contact lenses or may actually be
the result of contact lens wear. A normal and stable tear film is necessary in
order to be a successful contact lens wearer who does suffer from symptoms of
dryness and grittiness. To have good tear film stability means that the normal
natural tear film is able to maintain itself in a fairly uniform layer on the
cornea. Mother nature has provided us with a mechanism for achieving normal tear
film stability in the form of certain anatomical features found on the outermost
layer of the cornea, the corneal epithelium. The normal healthy corneal
epithelium is covered with microscopic "hairlike" structures call microvilli.
These microvilli act to provide a "roughened surface" for the normal tear film
to adhere to and thus give it stability in between each time you blink your
eyes. Unfortunately, over years of wearing contact lenses, it is believed that
constant rubbing and movement of the contact lens across the surface of the
cornea may in fact damage and deplete the presence of these epithelial
microvilli resulting in a less stable tear film and contact lens induced dry eye
symptoms. Again, this is not a sight threatening complication, but one that
makes contact lens wear less comfortable and sometimes results in an inability
to wear your contact lenses, even if you change lens materials and use
lubricating eye drops. Once you have completely discontinued wearing your
contact lenses, it is thought that the microvilli will resume their normal
presence over some period of time and in most if not all cases, the tear film
will return to normal.
According to the United States Food and Drug Administration (http://www.fda.gov/fdac/features/1998/298_lens.html),
"The most serious safety concern with any contact lens is related to overnight
use. Extended-wear (overnight) contact lenses--rigid or soft--increase the risk
of corneal ulcers, infection-caused eruptions on the cornea that can lead to
blindness. Symptoms include vision changes, eye redness, eye discomfort or pain,
and excessive tearing."
James Saviola, O.D., Chief of the Vitreoretinal and Extraocular Devices Branch
at FDA's Center for Devices and Radiological Health states, "The risk of corneal
ulcers for people who keep extended wear lenses in overnight is 10-15 times
greater than for those who use daily wear lenses only while awake." Dr. Saviola
explains, "When the eyes are open tears carry adequate oxygen to the cornea to
keep it healthy. But during sleep, the eye produces fewer tears, causing the
cornea to swell." The swelling and lack of oxygen leaves your eyes vulnerable to
infection.
Even though the FDA has approved extended wear contact lenses for overnight use,
there are risks with use of extended-wear lenses, "even if it's just one night,"
says Dr. Saviola. Unfortunately, for those patients who are seeking convenient
vision correction, extended wear or "30-Day" lenses may not provide a choice
without certain safety concerns as indicated by the FDA's opinion. These safety
concerns should be weighed carefully when considering LASIK and contact lenses
as the conventional wisdom that contact lenses are a "simple on-line consumer
purchase" may not reflect the reality. On the other hand, daily wear lenses that
are removed daily for cleaning and are a safer choice, provided they aren't worn
during sleep. Unfortunately, daily wear contact lenses do not provide the
convenience LASIK can provide and so the decision needs to be weighed even
further.
Another potential sight threatening concern is the infection Acanthamoeba
Keratitis, caused by improper lens care and possibly bathing in hot tubs or even
swimming. This difficult to treat parasitic infection's symptoms are similar to
those of corneal ulcers. For patients considering whether to wear contact lenses
or to have LASIK, if they need clear vision while swimming, they may wish to
consider this potential serious infection in the risk profile. Or, they may wish
to simply not wear contact lenses while swimming—but again this negates the
benefits you are trying to achieve in terms of lifestyle, functioning and
convenience.
So, while contact lenses have been reduced to being an on-line purchase implying a "care free, trouble free and risk free" form of vision correction, this may not be entirely correct. In fact, recent reviews and publications (Mathers, W.D., Archives of Ophthalmology, October 2006; Vol 124: pp1510-1511) of the safety and risks of wearing contact lenses as compared to having LASIK indicate that LASIK is indeed less risky over the long haul (http://www.webmd.com/content/article/128/117072).
Back
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If I
wear eyeglasses, How should I choose between contact lenses
and LASIK? ;
Vision Performance
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Convenience & Comfort
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