Relifting preferred over recutting flaps for LASIK enhancements, surgeons say

ATHENS — Lifting rather than recutting the primary LASIK flap seems to be the most popular choice among refractive surgeons when performing enhancement procedures, according to several surgeons speaking here at the ESCRS Winter Meeting.

"Lifting is safer," said Vikentia Katsanevaki, MD. By using a blunt instrument and touching the cornea with a little pressure, the edge of the primary flap can be "easily recognized," she said.

"In my experience, there is no flap that cannot be lifted. The important thing is that you should not traumatize the epithelium, to avoid the risk of diffuse lamellar keratitis (DLK) and inflammation. The less manipulation of the flap, the better," she said.

When re-treating, surgeons should make sure the cornea is dry because water changes the ablation rate and may result in undercorrection. Pachymetry should be routinely performed.

Flap thickness and quality are also important in deciding whether to relift or recut the flap.

"I normally relift the flaps of my own patients but prefer to recut a flap that has been made by someone else unless I'm completely sure of its thickness and quality," said José Güell, MD. "I feel much more confident recutting than assuming the risk of relifting and finding that it is not the diameter I wanted or the quality I expected."

Dr. Katsanevaki objected, stating that "there is no such thing as a perfect flap."

"If you remove the epithelium you find that every flap is wrinkled," she said, noting that she would only consider recutting a flap if there are obvious problems, such as scarring that suggests a buttonhole, or other flap-related complications. She would also consider recutting in cases in which there was inflammation after the primary LASIK procedure, which increases the risk of epithelial ingrowth.

A survey of 50 surgeons regarding their preference for lifting vs. cutting the flap during enhancement procedures, conducted between 1998 and 2002, showed that attitudes have changed over time. Initially, almost 20% of surgeons surveyed cut new flaps, but in more recent years the number has dropped to less than 1%.

"It is now evident that cutting the flap can create significant complications and jeopardize the ability to enhance again," Dr. Katsanevaki noted. "Even if I do not have flap thickness information from the previous procedures, I tend to lift because it is safer for the patient and gives me more freedom for enhancement."

In terms of biomechanical responses, Cynthia Roberts, MD, said that enhancement procedures produce little changes.

"You have already had the majority of the response with the first flap and the first ablation. Whether you relift or recut the flap, since you are just fine-tuning, the biomechanical response from the ablation will be minimal," she said.

However, cutting a second flap produces a more complicated structure, she noted.

"I have seen cases where the multiple procedures led to not only different diameter flaps, but also different diameter ablations," Dr. Roberts said.