Suturing effective for managing LASIK flap dislocation

Suturing is preferred over the “lift and smooth” technique for large epithelial defects and other situations, a surgeon says.

Issue: May 1, 2001

ByBob Kronemyer

NEW YORK — For managing LASIK flap dislocations, surgeons can use the “lift and smooth” technique when there is intact epithelium and the patient has short-lived striae. But in the presence of a large epithelial defect or poor epithelial adhesion, and especially in eyes with striae of longer duration, suturing appears to be more effective.

“Flap dislocation is a condition in which the flap is not securely attached to the keratectomy bed. The flap becomes misaligned, edematous and irregular with striae,” said Mark G. Speaker, MD, PhD, a corneal and refractive surgeon in private practice and a clinical associate professor of ophthalmology at The New York Eye and Ear Infirmary.

Patients with flap dislocation often present 1-day postop with pain, photophobia, poor vision and dislocation in part or all of the flap, as well as prominent accordion-like folds. Epithelial ingrowth is also usually present.

Varying degrees

Flaps with striae have folds that are similar to dislocated flaps, “except they are much more subtle. These flaps also look grossly normal,” Dr. Speaker said. They also seem to share the same etiology and considerations for prevention and treatment.

“The flap edge fails to remain adherent to the edge of the keratectomy bed. It is useful to think of them both as flap dislocations of varying degrees — macroscopic versus microscopic dislocations.”

Microscopic dislocations or striae are about five times more common than macroscopic dislocations. “Microscopic dislocations present later in the postoperative course because they are more subtle. They usually are diagnosed at the 1-week visit,” Dr. Speaker said.

Traumatic flap dislocation can occur as early as day 1 and as late as 15 months or more after surgery. “In the early postoperative period, traumatic flap dislocation is usually due to eye rubbing by the patient,” Dr. Speaker said. When the flap becomes more secure, though, it often takes a point or sharp object to dislodge the flap. Fingernails, pool cues and tree branches are common culprits. Most patients who sustain eye trauma after LASIK do not dislocate their flaps, he said.

In flap dislocation, the flap is not securely attached to the keratectomy bed and becomes misaligned, edematous and irregular with striae.

Flap edema

Thin flaps created by the microkeratome, an inaccurately repositioned flap, trauma from speculum removal or eye rubbing and any of the several causes of flap edema may all be implicated in flap dislocation. In particular, excessive irrigation can cause flap edema.

“This results in edge retraction, which presumably places the flap at greater risk for dislocation. Therefore, we should try to minimize flap edema,” Dr. Speaker said.

Avoiding excessive irrigation/hydration of the flap is key. “With superior hinged flaps, try to keep the edge of the flap out of the superior fornix where the fluid pools by folding the flap like a taco or keep the edge on a cushion made of sponge,” he said. Also ensure adequate removal of fluid from the interface and drying of the flap. Before removing the speculum, re-oppose any flap edge area where the gutter is widening. A striae test to ensure adequate adherence is also recommended.

Flap striae are microscopic folds seen in otherwise normal flaps of eyes with and without loss of visual acuity.

Patients should wear protective eye shields until their first postop visit. “I also tell my patients to avoid contact sports for about 1 month,” Dr. Speaker said. Eye protection is encouraged for any activity where trauma from fingernails or other pointed/sharp objects can occur.

If edge flap appears retracted immediately after surgery and before discharge, carefully reinsert the speculum, stretch the edge flap to reduce gutter size and minimize further irrigation/hydration if possible. “Allow 5 minutes for drying of the flap, then re-examine in 30 minutes,” he said.

Two techniques

Dr. Speaker employs one of two techniques for a dislocated flap.

“The first is the ‘lift-and-smooth’ technique described by Probst and Machat, whereby any epithelial ingrowth is removed. The epithelial edge is recessed to beyond the edge of the keratectomy bed,” he said. Moistened, then dry sponges and curved tying forceps stretch the flap for 15 to 30 minutes.

“I avoid hypotonic solutions because they tend to swell the flap and I think they are counterproductive,” he said. Tight-fitting bandage lenses are used for small epithelial defects. For a larger epithelial defect or epithelial slough, though, the lift and smooth technique is not effective, he said. Instead, he uses a flap suture technique comprising five to seven interrupted 10-0 nylon sutures.

Suture repair is more effective than the "lift and smooth" technique for dislocation with epithelial defect or slough and at greater than 1 month postop for striae.

“I place the sutures at 50% depth, skipping the hinge and placing them radially under moderate tension,” Dr. Speaker said. The sutures remain for 1 to 6 weeks, depending on the severity and duration of the striae.

“I also prefer suturing patients who are more than 1 month postop with striae or microscopic dislocation,” he said.

In a series of 26 eyes sutured by Dr. Speaker, 6 eyes were sutured because of macroscopic or large dislocations. On average, the 6 eyes improved from 20/200 best corrected visual acuity to 20/20. The remaining patients with striae or microscopic dislocation (most of whom had failed prior lift and smooth procedures) underwent suturing at about 2 months postop. These patients improved from 20/40 to 20/25.

For Your Information:

Mark G. Speaker, MD, PhD, can be reached at 115 E. 57th St., 10th Floor, New York, NY 10021; (212) 832-2020; fax: (212) 832-9739; e-mail: lasikspeak@aol.com.