Surgeons who perform refractive surgery have often been viewed as being on the cutting edge, but it doesn't mean they can't be cautious when they have to be. That's the case with this month's National Panel Report on refractive surgery. In it, surgeons report that the average thickness of their LASIK flaps is decreasing, and that most of them are altering their practice patterns based on the threat of ectasia.

 

Those are just a few of the results from this month's report. In it, 31 surgeons, or 6 percent of the 500-surgeon sample, responded.

 

LASIK and Flaps

LASIK is still the dominant procedure among our panelists, with 77 percent of the surgeons saying it's the procedure they use for most of their cases. The rest choose PRK. Breaking down the LASIK responses, 39 percent choose custom LASIK, 25 percent use wavefront-optimized LASIK with the Alcon Allegretto and 13 percent prefer conventional LASIK. For making their flaps, 43 percent of the respondents use a femtosecond laser, with the rest using a microkeratome.

Of the surgeons who perform surface ablation, all of them say the use mitomycin-C prophylactically to stave off haze and regression. "We use mitomycin-C on all cases where there has been previous corneal surgery—PRK, Intacs, CK, PKP or LASIK," says a Florida surgeon. "We also use mitomycin-C on cases with deeper ablations, above 60 µm, and in cases where the patient is at increased risk for haze, such as someone who is a boater."

When surgeons have to perform a LASIK enhancement, 57 percent say they lift the flap and ablate the stromal bed, while 43 percent avoid performing another LASIK and instead ablate the flap. No one advocates recutting a LASIK flap. "Never recut a flap," avers Andrew Caster, MD, of Beverly Hills, Calif. "Healing is faster and more predictable with lifting of the flap, and flaps can be lifted 10 or more years after creation. The main risk with lifting is epithelial ingrowth. My recent paper showed an 8 percent risk of clinically significant epithelial ingrowth that required treatment associated with flap lifts three or more years after the original flap creation.1 Because the epithelial ingrowth is easily and effectively treated, and because the healing is so much faster with flap-lift than with PRK enhancement, I typically choose to perform my enhancements with flap-lift."

A surgeon from North Carolina may have this ingrowth risk in mind when he says, "If it's less than two years postop, I'll usually lift the old flap and do LASIK. If it's more than two years, I prefer a transepithelial PRK." A surgeon from New Jersey, however, prefers to ablate the flap and not relift it. "I'm concerned about epithelial ingrowth," she says.

As many surgeons are experiencing in their own practices, LASIK volume has decreased an average of 33 percent for 46 percent of the respondents to the survey. Volumes stayed level for 26 percent of the surgeons, while 26 percent say it's increased for them by an average of 16 percent.

In terms of the bottom line, here are the average prices and costs the panelists report for their refractive surgeries:

    • average charge per eye for LASIK: $2,257;

    • average increase in price for custom LASIK over conventional: $233

    • average facility fee paid for LASIK: $603;

    • average charge per eye for PRK: $1,850;

    • average charge per eye for clear lens exchange/intraocular lens implantation: $4,800.

 

Ectasia Concerns

For their initial LASIK, surgeons seem to be gravitating toward thinner flaps as a hedge against ectasia risk. The surgeons report an average flap thickness of 121 µm. This thickness has been steadily decreasing since 2007, when surgeons said they were shooting for, on average, flaps of 130 µm.

"I usually leave a stromal bed of at least 300 µm vs. 250 µm," says Paramus, N.J., surgeon Douglas Liva.

Ninety-two percent of the panelists also say that the extra attention that's been paid to ectasia has affected the way they approach potential refractive-surgery patients.

"I focus more on ectasia during the informed consent process," says a surgeon from New Jersey. "I'm also more strict about pachymetry and topography criteria." A fellow New Jersey surgeon agrees, saying, "I now take a more conservative approach to prospective patients." A Florida surgeon also takes a harder look at topography. "I pay very close attention to the topography," he says. "That, in my opinion, is the biggest indicator of the risk for post-LASIK ectasia."

Many surgeons say this conservative approach takes the form of performing more surface ablation, and saving some of the tissue that would be ablated with LASIK.

"I perform PRK on patients whose corneas are under 500 µm in thickness," says Charleston, S.C., surgeon Sidney Seltzer. "And I don't operate on corneas with abnormal corneal topography." A surgeon from Delaware also shies away from LASIK in certain patients. "If the residual stromal bed will be below 300 µm, I perform Epi-LASIK," he says. "I'm now using more surface ablation in high-risk cases," agrees a surgeon from Chicago.

 

Preferred Procedures

Surgeons were also asked how they would approach patients with certain refractive errors. Here's how they responded for different patient presentations:

   • -3 D myope.Custom LASIK was the most popular choice for this type of patient, and it was chosen by 62 percent of panelists. A quarter chose PRK and 12 percent chose conventional LASIK. "Custom LASIK easily solves the problem," says Frank Rosenbaum, MD, of Lansing, Mich.

A surgeon from North Carolina agrees, saying, "Custom LASIK gives great results in these patients." New Hartford, N.Y., surgeon Anthony Palumbo, however, would do PRK. "It avoids ectasia," he says. "And it avoids any flap complications in both the present and the future." A PRK supporter from New Jersey says the procedure's benefits stem from "having no flap and offering a reasonable recovery."

   • -6 D myope.Custom LASIK is still the most popular option for this level of correction, with 62 percent of the surgeons saying they prefer it. Twenty-three percent would do surface ablation and 15 percent like conventional LASIK.

"My treatment of choice for this patient is PRK with the Allegretto Custom Wave," says Dr. Palumbo.

   • -11 D myope.For the high myope, 60 percent of the surgeons say the best procedure is probably a phakic intraocular lens. Thirteen percent think clear-lens extraction/IOL implantation is the way to go, 13 percent like PRK, 6 percent would do custom LASIK and 6 percent would choose LASEK.

"LASIK is too invasive in the cornea for this patient," says Michigan's Dr. Rosenbaum, who advocates a phakic IOL. A surgeon from New Jersey also thinks a phakic lens is the best option, saying, "With a clear lens extraction/IOL implantation, the risk of a retinal detachment is high."

   • +2 D hyperope.For the low hyperope, 60 percent say that LASIK would be the best procedure, 20 percent like PRK and 20 percent recommend clear lens extraction. "LASIK works well with low hyperopes," says Dr. Seltzer. However, Dr. Palumbo thinks the surface is the place to be. "PRK is controlled and safe," he says. "And I'm guided by past accuracy and results with it." But a surgeon from Florida likes CLE. "The challenge if LASIK is performed in this case is that one eye would require a 2-D correction, but the near eye would need a 3.5-D correction to end up at -1.5 D," he says.

RO

 

1. Caster AI, Friess DW, Schwendeman FJ. Incidence of epithelial ingrowth in primary and retreatment laser in situ keratomileusis. J Cataract Refract Surg 2010;36:1:97-101.