STORY BYIf Santa gave you corrective vision surgery a few holidays ago and it's no longer working, there's a new stocking stuffer in town.
Patients who had radial keratotomy (RK ) to improve their vision and have since developed farsightedness may be candidates for a laser procedure to further correct eyesight without the aid of glasses or contacts.
Richard W. Yee, M.D., clinical professor of ophthalmology and visual science at The University of Texas Medical School at Houston , is using laser epithelial keratomileusis ( LASEK ) to correct vision problems that have occurred over time.
"In the late '70s, '80s and 90s, radial keratotomy was very popular in the United States ," Yee says. "A lot of people had great vision as a result of the procedure, but now these patients are hitting their 40s and 50s, and some are undergoing what's known as hyperopic shift where their eyes become overcorrected."
Their near vision becomes worse, so they have to wear glasses to read. Some may experience residual myopia, where they need glasses again for distance vision.
With LASEK, which requires no cutting of the cornea, Yee can offer a safer, more stable and more predictable alternative to other surgical procedures that are currently available.
Yee places a cone marker in the eye, and pours a dilute alcohol inside. The alcohol loosens the epithelium (top layer) of the cornea before Yee dries the area and uses a small instrument to lift the epithelium.
The flap of the epithelium is gathered at the top of the eye. Afterward, Yee uses a laser to shape the cornea, and then he gently puts the epithelium back in place and covers the eye with a soft contact lens to protect the area while it heals.
Because the surgeon isn't cutting a "trap door" in the cornea-the older style of correction-- there is more tissue to work with, which offers greater structural stability and a larger range of vision correction.
There is some post-op pain, and the healing time is longer with LASEK-a few days rather than a few hours—because it takes longer for the corneal surface to reattach itself, but Yee says the vision results are generally better than what patients would get with traditional laser surgery.
The procedure works well for patients such as Stephen Larson, M.D.,who had RK is the late '80s. "For a number of years after the surgery, I had excellent vision. Then when I hit age 45, I began to have trouble seeing what I was reading," said Larson, professor of anesthesiology at The University of Texas Medical School at Houston .
He went from 20/20 vision to reading glasses and eventually began to wear contacts. When the contacts began to cause itching, burning and redness in his eyes, he was saddled with wearing glasses all the time.
"The glasses were always sliding down my nose and getting in the way of the masks we wear in the OR," Larson said. "I wanted something better."
Yee recently corrected Larson's right eye for distance and did a separate LASEK procedure to correct the left eye for reading.
"The beauty of the laser is that it's such a minimal but specific thing," Larson said. "There isn't any long-term data, but Yee thinks this correction could last five or more years. In my opinion, five years of good vision without glasses or contacts is well worth it."
Yee says it is important for aging RK patients to go to an eye professional who understands the special challenges of correcting a cornea that has had RK.
"If you don't use the right equipment, you can shear the cornea into pieces," he warns.
With RK, the cornea already has been cut, so offering a procedure that eliminates additional cutting will provide correction without further compromising the cornea's stability.
UPDATED: 11-17-2003
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Dr. Richard Yee is a clinical professor in the Department of Ophthalmology and Visual Science at the UT Medical School.
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Tetanus booster for adults
Tetanus does not result from the rusty nail or whatever created the wound. The danger lies in the bacteria Clostridium tetani that lives in the soil or manure on that nail or gardening tool. When these spores get into a wound—deep or shallow—they can produce a potent toxin. Also called lockjaw, tetanus seriously affects the central nervous system and can be fatal.
Onset of symptoms can occur anytime from three days to three weeks. Call your health care provider if you have an open wound, particularly if:
Adults should have a tetanus booster shot every 10 years, known as the Td vaccine. It is a "2-in-1" vaccine that protects against tetanus and diphtheria. It contains a slightly different dose of diphtheria vaccine than what you received as a child. It can be given to anyone older than 7 years and is injected, usually into the arm.
Instead of the standard Td booster every 10 years, adults between the ages of 19 and 65 should receive Tdap one time in their adulthood to boost the immune system for pertussis, as well as tetanus and diphtheria.
Diphtheria, a contagious bacterial infection created that causes severe inflammation of the throat and larynx and can also affect the whole body. Pertussis or “whooping cough” is a serious bacterial infection that afflicted children and infants before vaccines were available. Adults may be infected later in life as their immunities wane. Neither of these infections are related to tetanus, but both vaccines are compatible and convenient to use with the tetanus booster.
