With LASIK, many myths are being created and discarded

Among the myths that are now believed to be false are that LASIK flaps cannot be lifted in the distant future and that you cannot remove flap wrinkles after 2 weeks.

Issue: August 1, 2000

ORLANDO, Fla. — As the laser in situ keratomileusis (LASIK) industry grows and fans out, many different myths are being created and destroyed almost every day. Some of those myths were put on display during the American College of Eye Surgeons Quality Surgery conference here. John R. Wright, DO, explained that many of the myths circulating today are just that — myths.

In his practice, Dr. Wright said he has faced many cases where the technique and the end result certainly blew apart the myth.

Among the first myths he broke was certainly one many surgeons can be accused of following, that being that “when you’re an experienced surgeon, you don’t have to check tonometery intraoperatively.” Dr. Wright explained that the experience of surgeons could work against them. “Here I ignore a soft reading. It’s the worst mistake to see that it’s a soft reading and not believe it,” Dr. Wright said.

“Taking a pressure reading only adds 5 seconds to the procedure, and I don’t see any other way to detect false occlusion than to quickly check the pressure,” Dr. Wright said. The patient ended up with a smaller irregular flap and was not able to be treated at that time. He had to wait 3 months.

Flap myths

First among the myths was that lifting the flap too long after LASIK surgery was ill advised. “You can lift a flap years later,” Dr. Wright said.

He felt that even though the flap may be bonded down, it was still a better alternative to cutting the flap. “The microkeratome is the main risk of LASIK. Why risk that any more than is necessary?” Dr. Wright said.

His preferred method includes using a Sinskey hook and a toothless forceps. He showed how he once chose to re-cut a flap, but by using the microkeratome again, he intersected the undersurface of the first flap, which resulted in an irregular surface with little bits of extraneous tissue. The patient he treated 3 years ago only had best corrected vision to 20/30 and irregular astigmatism. “Every time you recut the cornea, that lessens the amount of cornea available,” Dr. Wright said.

He does, however, always re-cut flaps when they have poor flap quality, are thin, irregular or buttonhole. “Otherwise, I always lift the flap. Our record is 3.5 years,” Dr. Wright said.

He was quick to say that just because it can be done, that does not mean there are no dangers with lifting flaps.

Dr. Wright’s standard technique is to look for the edge of the flap with a Sinskey hook. “In one patient who had had PRK followed by LASIK, which was then followed by a LASIK enhancement, I was a little surprised that when we lifted the flap, we got a little tear right where the flap intersected the photorefractive keratectomy treatment zone. This is the only case where I encountered that problem. I’m not sure if we all need to be aware of that or not. I basically just put the flap back and recut the flap in 3 months,” Dr. Wright said.

Problematic flap myths

Some surgeons believe that it is impossible to remove flap wrinkles after 2 weeks postop. “I don’t know how these [myths] get started, but the best technique it is to lift the flap, hydrate it, smooth it and stretch it,” Dr. Wright said.

A patient was about a month removed from the original LASIK when he bumped his eye and wrinkled the flap. This patient then had significant wrinkles across the visual axis. Dr. Wright said that sometimes he finds it is not possible to always eliminate all microstriae from the slit lamp exam, but that it is possible to remove them from the visual axis to the point where the patient no longer has decreased visual acuity from the striae.

He pointed out that a good sign that the striae are visually significant is if the striae leave an impression on the stroma. “That pretty well clinches it,” he said.

Dr. Wright said he prefers to use sterilized balanced salt solution and to stretch with the spatula to get rid of the wrinkles. “Everyone who does LASIK realizes that you’ll still see the wrinkles after you’ve stretched the flap at the time of surgery, but by the next day, those wrinkles are gone,” Dr. Wright said. He also mentioned that the longest period of time he has removed wrinkles is 1 year postop.

Another myth that is bandied about is that recurring and recalcitrant epithelial ingrowth is best treated by removing the flap. “I had that advice given to me in a very difficult case I had to deal with by several people whom I respect. They said the flap was becoming edematous and was losing its transparency and that it was probably best to remove the flap and just let it re-epithialize. This patient had severe recurrent epithelial ingrowth. We had already cleaned it four times. We had sutured the edge,” Dr. Wright said.

Instead of removing the flap, he chose instead to take a Beaver blade and scrape the back of the flap and the stroma. “It occurred to me that if we could create a little pocket — a lamellar pocket — and tuck the edge of the flap into the pocket, we could create a physical barrier that would prevent epithelial ingrowth from recurring again,” Dr. Wright said. He chose to use a diamond knife and a number 69 Beaver blade to create a lamellar pocket on the temporal side where the epithelial growth likely kept coming in. He then used a spatula to make certain the flap was tucked in.

He said it was a relief to finally have this patient’s problem resolved. The last time he saw the patient was 1 year postop with 20/25 uncorrected visual acuity.

For Your Information:

John R. Wright, DO, can be reached at 2920 N. Cascade, Colorado Springs, CO 80907; (719) 634-2001; fax: (719) 634-2211.