LASIK Surgery Nothing to Blink At
Study: Dry eye a possible problem for contact wearers
TUESDAY, Aug. 7, 2001 (HealthDayNews) -- The ads for LASIK surgery promise clear vision without glasses or contact lenses, but a new study says the popular therapy also can cause serious, permanent vision loss for some people, in particular, longtime users of contacts.
"My fear is that those who are candidates for trouble won't find out until after they have the surgery, and then it might be too late," says lead study author Dr. Lisa Battat, director of corneal and refractive surgery at the Everett and Hurite Ophthalmic Association in Pittsburgh.
LASIK (laser-assisted in situ keratomileusis), also known as refractive surgery, utilizes small cuts in the cornea to change its shape and restore near-perfect vision. It can cause a temporary condition called "dry eye," a lack of moisture on the surface of the cornea that can severely disrupt vision.
"It used to be thought that only about 5 percent of people get dry eye after LASIK surgery, but no statements were ever made about whether it was long- or short-term," says Battat.
Battat says hers was the first study to look at dry eyes with long term follow-up, and the results are a wake-up call about the safety of the operation.
"In some patients, dry eye can become so severe it results in long-term vision problems following LASIK surgery," she says.
Another doctor who performs LASIK says the observation about "dry eye" is correct, but it's not an obstacle.
"We have long known about dry eye, and there are steps you can take both before and after surgery to insure against problems," says Dr. Sandra Belmont, director of corneal service and an associate professor of ophthalmology at New York Weill Cornell Medical Center. "This is a very safe operation with very little chance of any long-term complication."
Battat says dry eye develops when inadequate tear production prevents the surface of the cornea from being adequately bathed in the slick, wet coating necessary for clear vision.
In addition to LASIK surgery, dry eye can be caused by an autoimmune disorder like rheumatoid arthritis, by certain medications such as antidepressants, or, as is most often the case, by long-term contact lens use, which concerns Battat the most.
"Longtime users of contact lenses have a decreased sensitivity in their eyes, which, in turn, reduces the blink response and increases their risk of dry eye," says Battat.
Because LASIK involves cutting the corneal nerves, Battat says it always results in some lasting decrease in sensitivity. She says the difference for most patients is hardly noticeable after recovery.
However, if your eye is already less sensitive going into the operation, and your eyes are already dry, as is the case for many contact lens wearers, Battat says the chance that vision won't return to an acceptable level are greater.
"In the worst-case scenario, the patient needs long-term use of artificial tears -- on the order of every few minutes, sometimes indefinitely -- in order to see at all," she says.
While Belmont says that dramatic scenario could happen, she says it's extremely rare.
"This kind of thing would normally only occur if a person has an autoimmune disorder or some other medical condition that is causing extreme dry eye, and when that is the case, LASIK surgery is never recommended to begin with," says Belmont.
The new study involved 14 men and 34 women, ages 26 to 54, and a total of 48 eyes. All underwent bilateral LASIK for nearsightedness, with and without astigmatism.
Each patient's vision, including indication of dry eye, was evaluated one to two days before the surgery, as well as seven days afterward. Patients were tested again at one, two, six, 12, and 16 months postoperatively.
All of the patients had decreased eye sensitivity, resulting in a lack of tears (dry eye) and a resulting decrease in vision that called for regular use of artificial tears for an extended time. The study appeared in the July issue of Ophthalmology, the journal of the American Academy of Ophthalmology.
For Belmont, the findings are interesting, but don't represent a real treatment challenge.
"There are things that can be done prior to surgery that, in almost all instances, can insure against any permanent problems related to dry eye, and, in fact, prevent any significant dry eye from occurring at all," she says.
Preoperative therapies include topical cyclosporin medications, artificial tears and sometimes minor surgery to block tear ducts, thus increasing fluid in the eye, Belmont says.
What To Do
To avoid problems, both experts say make certain your eyes are properly examined before surgery, particularly if you wear contact lenses. If tear production and corneal sensitivity are low, Battat says don't have LASIK until the problems are corrected.
To learn more about symptoms of dry eye and what you can do about it, visit St. Luke's Cataract and Laser Institute.
To read more about the pros and cons of LASIK surgery, try the Food and Drug Administration.