Refractive Surgery
Femto laser comes of age in refractive surgery

AT A GLANCE

• Ophthalmic surgeons praise the femtosecond laser for its reproducibility, predictability, and safety
• The laser’s stance in the refractive market for 10 years has allowed surgeons to see how the technology has evolved
• Cost is a major drawback of the femtosecond laser compared with mechanical microkeratome use. However, many physicians pass the added cost on to patients
8 Investigators are exploring use of the femto laser in cataract surgery, corneal surgery, keratoconus, and other areas of ophthalmology

Precision, predictability, and potential for other uses
garners wide interest

Customized LASIK with two different microkeratomes increases the mean spherical aberration at all pre-op levels, while a pre-existing mean spherical aberration above 0.38 um can can actually be lowered with Customized IntraLASIK; this is due to less biomechanically induced spherical aberration with IntraLASIK flaps


Example: after making only the flap with a microkeratome in one eye and IntraLase (AMO) laser in the other, the spherical aberration increases with the Moria (Antony, France) microkeratome, but slightly decreases with the IntraLase; the change in refraction and wavefront also shows a greater shift toward hyperopia with the Moria microkeratome than with IntraLase.
Source: Ronald Krueger, M.D.

Bye, bye, microkeratome? 2010 will be the year of the femtosecond laser, many ophthalmic surgeons predict. First, the femtosecond laser has come of age thanks to studies that show safety, predictability, and reproducibility with its use during refractive surgery.
“Femtosecond LASIK creates a better flap,” said Capt. (Ret.) Steven C. Schallhorn, M.D., San Diego, and medical director, Optical Express, London. “Patient outcomes and safety are improved.” Dr. Schallhorn has been involved with two independent studies that show how the femtosecond laser is efficient, effective, and has a low complication rate. One study published last year in the Journal of Refractive Surgery found that a larger percentage of eyes in which the femto laser was used achieved a post-op uncorrected visual acuity of 20/20 or even 20/16 up to three months after surgery compared with mechanical microkeratome use.
“When I talk to patients about the laser, I talk about reproducibility and greater safety—there’s less chance of irregular cuts or complications. Buttonholes, free caps, and partial flaps are almost eliminated with the femtosecond laser,” said Ronald R. Krueger, M.D., professor of ophthalmology, Cleveland Clinic, and medical director, refractive surgery, Cole Eye Institute, Cleveland.
“Another advantage with the femto laser is if you go part of the way and lose suction, you can stop, reapply suction, and start over,” Dr. Krueger said, adding that surgeons do not have that same luxury with the mechanical microkeratome.
“If I have 20 cases scheduled at the start of the day, I have confidence that I won’t have difficult complications with the femtosecond laser. I never had that comfort with the microkeratome,” said Steven E. Wilson, M.D., professor of ophthalmology and director, corneal research, Cole Eye Institute. “Even though complications were not that common with the microkeratome, when they did occur, they could be very severe.”
Safety and efficacy are no doubt the primary reasons that the femto laser has gained steam, but Daniel S. Durrie, M.D., clinical professor of ophthalmology, University of Kansas, Overland Park, Kan., believes that laser technology reaching the 10-year mark makes a difference as well.
“There’s something magical about 10 years in ophthalmology,” he said. Often, technology has to remain in the field for about this length of time to prove itself before a larger mass of surgeons will use it more often or exclusively, he said.

The numbers behind laser use

Although these surgeons’ enthusiasm for the femtosecond laser in refractive surgery is obvious, statistics show that 62.2% of refractive procedures (including surface ablation) performed in the third quarter of 2009 in the U.S. were done with the femtosecond laser, according to MarketScope, St. Louis. This statistic focuses on the actual number of procedures done and not the number of practices that own a femtosecond laser.
The interest in lasers is also obvious in the growing number of manufacturers who are now making femto lasers. Originally, IntraLase (Abbott Medical Optics, AMO, Santa Ana, Calif.) was the major player. Now, WaveLight (Alcon, Fort Worth, Texas), Ziemer (Port, Switzerland), and Technolas (St. Louis), among others, are manufacturing these lasers. “They wouldn’t invest in the market if there was not a demand,” Dr. Durrie said. Several other potential manufacturers also are purportedly entering the market soon, Dr. Schallhorn said.

The cost factor

The biggest downside to the femtosecond laser may be its cost compared with mechanical microkeratomes, many surgeons said. In fact, were it not for the cost issue, many more surgeons would likely already be using the laser now during refractive surgery, they said. “The microkeratome is $50,000 plus about $50 for the blade. The laser is $300,000. Each time you use it, it’s about $150 per patient. That’s six times more expensive,” Dr. Krueger said.
Some surgeons may opt to stick with the microkeratome for now because they are moving around to different surgery centers, Dr. Krueger said. In that respect, the microkeratome is more mobile.
Additionally, from a global perspective, microkeratomes are still used more often than the laser in refractive surgery. “Individual practices have to do a cost analysis,” Dr. Schallhorn said. In some markets, there are surgeons who perform LASIK with the femtosecond laser at a very cheap price and ones who perform it more expensively, yet both still survive, Dr. Krueger said.
That all said, the economy has not made a complete recovery yet, and the laser’s steep price means it should not be an impulse purchase. “Few practices, even those with their toes back in the water promotionally, are seeing much of a first-quarter case-volume resurgence,” said John B. Pinto, president, J. Pinto and Associates, San Diego. “As a result, capital spending in the least-affected refractive surgery practices remains a tender subject.”
Although some larger dominant players and those goaded by local competitors to invest in lasers are purchasing the equipment, smaller-volume centers should opt for a more conservative approach, Mr. Pinto advised. “My guidance is to keep hunkering down for the next couple of years, spare capital outlays, and hang in there, while shifting efforts to the bread-and-butter domains of general/geriatric eye care,” he said. Mr. Pinto said that building up technology capital for when the refractive market turns around is a reasonable approach for small- to medium-sized providers.
Often, once the laser is purchased, providers pass the cost on to the patient. “Initially we offered patients the option of femtosecond or the microkeratome. Almost none chose the microkeratome, so we dropped that after awhile,” Dr. Wilson said. “Surveys find the patients are less concerned about cost because it’s a one-time surgery. It’s doctors who say it’s expensive,” Dr. Durrie said.

Exploring the laser’s potential

Because the femto laser is a relatively new and evolving technology, manufacturers and physicians are still exploring its potential. For example, its role in lowering dry eye after refractive surgery is one area under study. Dr. Wilson was co-investigator in a study published in the October 2009 Journal of Cataract & Refractive Surgery that found in the first 6 months after LASIK, there was far less dry eye—what investigators referred to in the study as LASIK-induced neurotrophic epitheliopathy—with the femto laser compared with mechanical microkeratome use.
Dry eye incidence did not change dramatically with thin or thick flaps created by the microkeratome, he said. Lowering dry eye after surgery can translate into fewer patients with fluctuating vision, fewer patients using Restasis (cyclosporine ophthalmic emulsion, Allergan, Irvine, Calif.), and, ultimately, fewer unhappy patients, he said.
Dr. Durrie would like to see the laser’s same-day visual recovery improved. “We have excellent one-day vision, but if you look at one hour after surgery, it’s not every good. There’s edema, vision is a little fuzzy, and 60%–70% of patients measure 20/40.” Although Dr. Durrie said he and other surgeons know that vision will improve rapidly by the next day, he considers the patient’s perspective. “When do friends call [and ask about the results]? Right after surgery,” he said.
Dr. Durrie would like to see femto LASIK become something like a dentist appointment, where patients can drive themselves to surgery and go back to work that same day. This will enable them to report better vision immediately and avoid depending on friends or family to assist them before and after the appointment.
The move to use femto lasers in other aspects of eye surgery also intrigues many surgeons. Recent promising reports of femtosecond laser use during cataract surgery to make the capsulorhexis and soften the nucleus, as well as with corneal transplants, keratoconus, and even presbyopia inside the lens all merit further study, surgeons said.
“I see the femtosecond laser as the new scapel in eye surgery,” Dr. Krueger said. “I imagine for the future it can take all kinds of directions as a cutting tool. We need a precise tool as sensitive as the eye, and this is what we have.”

Editors’ note: Dr. Schallhorn has financial interests with Abbott Medical Optics (Santa Ana, Calif.). Dr. Durrie has financial interests with AMO and Alcon (Fort Worth, Texas). Drs. Kruger and Wilson and Mr. Pinto have no financial interests related to their comments.

Contact information

Durrie: 913-491-3330, ddurrie@durrievision.com
Krueger: 216-444-8159, krueger@ccf.org
Pinto: 619-223-2233, pintoinc@aol.com
Schallhorn: 619-920-9031, scschallhorn@yahoo.com
Wilson: 216-444-5887, wilsons4@ccf.org