Surgery

Mickie Barg

Since he was 4 years old, Mark Heinlein has worn thick glasses. Yet Saturday, one day after his LASIK eye surgery at the University, the 38-year-old sales manager drove his car without any corrective lenses for the first time in his life.
LASIK surgery uses a laser to alter the shape of the cornea to correct astigmatism and nearsightedness.
Eye surgeon Andrew Huang said he normally treats patients with some nearsightedness or myopia and a little astigmatism, but Heinlein’s case was different because he had more astigmatism than nearsightedness.
“A normal cornea is like a round soccer ball,” Huang said. “Mark’s is like a football — very elongated. In order to carve his cornea back into a soccer ball, we have to use some finesse.”
Before surgery, Heinlein’s eye was numbed with local anesthetic eyedrops. He remained awake for the entire procedure.
A device called a microkeratome was suctioned onto Heinlein’s eye to separate most of the top layer of his cornea. A small part of the cornea was left connected to act as a hinge.
The laser, which had been pre-programmed with Heinlein’s exact measurements, shaved away the underlying portion of the cornea. Afterward, the flap was replaced.
“Imagine the eye as a watermelon,” Huang said. “We cut away the green part, leaving it on a hinge, then carefully use the laser to thin out the white part, and then put the green cap back.”
LASIK, which became widely used in 1989, uses a cold laser to sculpt the cornea.
Each laser pulse can remove 1/500 of a human hair and has no effects on the surrounding tissue.
LASIK is the preferred method of eye correction surgery because it allows for a short recovery time and low infection risk.
A possible problem with Heinlein was his deep-set eyes and prominent eyebrows. In order to do LASIK surgery, the eye must open wide enough to accommodate the microkeratome and cut the flap.
If the eye couldn’t be opened wide enough, photorefractive keratectomy, or PRK, would have been performed instead.
With PRK, the laser is used without the microkeratome, resulting in more trauma and a longer recovery time because the laser cuts through the entire cornea instead of just the bottom portion. Also, the eye is much more susceptible to future injuries because the cornea cannot fully heal.
“In the watermelon analogy, you would have to cut through the full thickness to get to the white so, upon impact, the watermelon is going to burst,” Huang said.
Another drawback to PRK is that the eye will progressively alter because of constant healing. For 25 percent of patients, this will result in farsightedness after about 10 years.
This does not happen with LASIK, but 30 percent to 40 percent of patients are rejected for the lower-impact procedure.
To qualify as a candidate for the procedure, doctors consider the patients’ age, size of the eye and shape of the cornea, eyesight stability, and any previously undetected eye diseases.
“At the University we are really conservative and only do ones that will really make a difference,” he said.
Huang said many advertisements simplify the procedure to alleviate anxiety.
“Whoever is interested should not be drawn into commercialism and take too lightly the procedure,” Huang said.
The procedure could have complications, although he has not seen many at the University due to the case selection and the precision of its machine.
“Many people ask about the procedure,” said Christine Janty, Boynton optometrist. “But the number actually going through with it are small.”
Boynton staff can make referrals and conduct pre-operative measurements and follow-up care, but they cannot perform the surgery.
Janty said some patients also do not follow through with LASIK surgery because of its high cost.
“Some students can’t even afford glasses or contacts,” Janty said. “And the surgery isn’t covered by insurance.”
There are some risks of infection and inflammation after surgery, but complication rates are very low — less than 1 percent — and are managed with post-operative care.
“There is a risk of infection, but not any higher than with regular contact lens wear,” said Neelu Hira, Boynton optometrist.
Heinlein considered having LASIK surgery for about two years. The deciding factors were an increase in its popularity and recommendations from friends and colleagues who had the procedure, he said.
“(They) said it was the best thing they have ever done and wish they had done it sooner,” Heinlein said.
He said the only discomfort he had during surgery was with the placement of the spreader to open his eyes. He added his vision was better immediately after the surgery.
“There’s a big difference in the sharpness,” Heinlein said, immediately after leaving the operating room. “Things are clear that weren’t in focus before. I just have some fogginess.”
Heinlein was alert during the procedure and later said he felt the sensation of drilling on his eye.
“I was smelling burnt flesh, which was me, I’m sure,” he said. “I could tell the laser was moving. I didn’t see it move, but I could feel it.”
The next morning, Heinlein’s sight was nearly perfect and he complained only of a little eye dryness and swollen eyelids.
But the rest of the morning more than made up for the discomfort. He read the newspaper and saw the street signs on his drive to the doctor’s office without the aid of his glasses.
Price for surgery at the University is higher than most LASIK surgery advertised and ranges from $1,250 to $1,600 for both eyes. The cost covers pre- and post-operative appointments and any enhancements or additional correction surgery needed within a year of the original procedure.
Huang said 10 percent to 15 percent of patients need further treatment or enhancement because he under-corrects to guard against abnormal healing.
“This is almost like a sculpture where I want a certain design or shape,” Huang said. “If I chip away too much then I won’t be able to put it back.”
Removing too much of the cornea will cause the patient to become farsighted.
The most recent type of vision-correction procedure approved by the FDA, laser thermal keratoplasty or LTK, could solve that problem. Right now, it is one of the only procedures that can correct farsightedness.
Unlike the LASIK procedure, LTK results may not be permanent and some of the correction could be lost over time.

Mickie Barg covers the medical school and welcomes comments at [email protected]