http://www.osnsupersite.com/view.asp?rID=25057

OCULAR SURGERY NEWS U.S. EDITION December 1, 2007

Survey finds LASIK losing ground as alternative procedures gain popularity
By Lauren Wolkoff; Katrina Altersitz; Erin L. Boyle; Matt Hasson; Jessica LougheryOSN at AAO

NEW ORLEANS — LASIK is waning in popularity amid the rise of refractive lens exchange, phakic IOLs and surface ablation, a recent survey found.

Richard J. Duffey, MD, discussed the annual survey conducted by the International Society of Refractive Surgery during Refractive Subspecialty Day preceding the American Academy of Ophthalmology meeting. The survey was conducted last August. More than 1,400 ISRS/AAO members were surveyed and 18% responded.

When surgeons were questioned on their preferred surgical method, Dr. Duffey said that “LASIK is down to about 33% from a high of 53% back in 2001.”

LASIK peaked about 5 years ago but has gradually made way for other refractive solutions including phakic IOLs, intracorneal ring segments and refractive procedures such as epi-LASIK, PRK and conductive keratoplasty (CK, Refractec), he said.
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Dr. Duffey said statistics show that phakic IOLs were preferred in 41% of myopia correction cases.

“Refractive lens exchange and phakic IOLs are up about 10% from last year in numbers of members who are doing these procedures,” Dr. Duffey said.

Phakic IOL implantation was the preferred procedure for a 30-year-old patient with 10 D of myopia. About 18% of surgeons preferred performing refractive lens exchange for a 45-year-old patient with 3 D of hyperopia.

A majority of surgeons preferred refractive lens exchange for a 5 D hyperope despite the fact that LASIK is approved for up to 6 D of hyperopia, Dr. Duffey said.

While a majority of surgeons preferred a LASIK flap thickness of 120 µm to 130 µm, 27% preferred a flap thinner than 100 µm, up from 19% who preferred a thin flap the previous year, he said.

More than half of respondents reported having experienced no incidence of post-LASIK ectasia. “The important thing is that those numbers are not growing. Maybe we’ve reached our peak,” Dr. Duffey said.

Sixty percent of surgeons said they were using wavefront-guided custom ablation when appropriate, he said.

Most of the following items appeared originally as daily coverage from the meeting on OSNSuperSite.com. Look for more in-depth coverage of these and other topics in upcoming issues of Ocular Surgery News.
‘Fourth-generation’ refractive procedures address limitations, expert hopes

The next generation of corneal refractive surgery is going back to the surface in an effort to resolve surgical limitations of conventional PRK, LASIK and LASEK, according to a keynote lecturer.

At the Refractive Surgery Subspecialty Day, John Marshall, PhD, explained his belief that sub-Bowman’s keratomileusis (SBK) performed with femtosecond laser technology represents the fourth generation of corneal refractive surgery.

The three previous generations include early PRK, which has been shown to produce significant haze and delayed wound healing, LASIK, which affects the biomechanics of the cornea, and LASEK and epi-LASEK, he said. Each of these techniques has its own limitations, he said.

“With surface ablation, you want to control wound healing. With LASIK, you want to control [corneal] biomechanics. Hence the suggestion of SBK, or creating a very superficial flap,” Dr. Marshall said. “It is stable, and because it minimally reduces the strength of the cornea, it should remain stable as well as surface procedures do.”

Dr. Marshall added that SBK will improve upon conventional LASIK by changing the edge angle of the flap to make it stronger. SBK also offers an advantage over conventional surface ablation in terms of wound healing. Early research on corneal applications of aptomers could also yield targeted wound healing control, he said.

In an effort to chronicle the limitations of conventional surgical techniques, Dr. Marshall said he and his colleagues have begun to study the effects of PRK, LASEK and LASIK at 4 to 6 weeks after surgery on human tissue by using a culture model. He said most research to date has been limited to rabbit or monkey corneas.
Psychiatrist recommends personality assessments for LASIK candidates


Jennifer Morse, MD
Jennifer Morse, MD, evaluated the role that personality plays in determining patient satisfaction and quality of life after LASIK.

Preoperative screening of refractive surgery candidates should include objective evaluations of personality factors, according to a psychiatrist.

Jennifer Morse, MD, worked with the Navy Refractive Surgery Center in San Diego to evaluate the role that personality and psychiatric factors play in determining patient satisfaction and quality of life after LASIK.

“The majority of patients are very satisfied after LASIK, but there is a certain subset who are very unhappy and very vocal,” Dr. Morse said at Refractive Surgery Subspecialty Day.

Dr. Morse evaluated 309 patients with a mean age of 36 years who were scheduled to undergo conventional LASIK. The patients were given a quality-of-life questionnaire and a standardized personality survey before and 6 months after surgery. The questionnaire was designed to assess quality of life, regret, nonvisual eye complaints, physical appearance and self-esteem.

While the majority of patients were “highly satisfied” with their surgery, it is the dissatisfied patients who should be every surgeon’s primary concern, Dr. Morse said.

“These are the people who take up your chair time, your phone time and your staff’s time. If you don’t respond to them, they’re out in the community and they’re on the Internet. Some go on to file lawsuits,” she said.

Personality is the one factor that cannot be mitigated in unhappy patients. “For all the technology you hear about today, you are not going to be able to change that. You need to assess it beforehand and counsel these people pre- and postoperatively and work with them on their personality styles,” she said.

Dr. Morse also stressed that personality tests must be objective, as surgeons’ own personalities can affect the way a surgical candidate is perceived. “Our goal is to develop customized screening tools you can use in your practice,” she said.
MMC useful in LASEK on thin corneas

LASEK performed in myopes with thin corneas yielded long-term stable results with the use of mitomycin-C, according to a study.

At Refractive Surgery Subspecialty Day, Miguel A. Teus, MD, discussed the results of a retrospective study of 64 consecutive eyes that had undergone LASEK to correct myopia or myopic astigmatism. All patients had central corneal thickness of less than 500 µm, Dr. Teus said.

“No other paper has studied this issue of stability of the refraction after mitomycin-C application in the operation,” he said.

The patients all received intraoperative MMC 0.02% over 30 seconds. Their results were reviewed between 3 and 15 months postoperatively to detect any myopic shift that might point to corneal ectasia, he said.

The patients’ preoperative central corneal thickness ranged from 454 µm to 499 µm, and their preop spherical refraction was between 0 D and –11 D. At 3 months postop, their central corneal thickness ranged from 339 µm to 472 µm, and the mean residual sphere was +0.2 D ± 0.5 D.

At 15 months postop, residual sphere remained stable at +0.2 D ± 0.8 D. Cylinder, uncorrected visual acuity and best corrected visual acuity also remained stable between 3 and 15 months postoperatively.

Dr. Teus noted that no eye developed any sign of ectasia.

Post-LASIK corneal neuropathy can mimic dry eye symptoms

Irregular nerve regeneration after LASIK may cause “phantom pain” that can be mistaken for genuine dry eye symptoms, according to the results of a study.

Ilpo S. Tuisku, MD, FEBO, presented his findings upon accepting the Richard C. Troutman Award at Refractive Surgery Subspecialty Day. The Troutman Award recognizes the work of young authors published in the Journal of Cataract and Refractive Surgery.

Dr. Tuisku attributed neuropathy to aberrant nerve regeneration, which can result from the severing of corneal nerves after flap creation and laser ablation.

“Subjective symptoms of dry eye resemble dry eye,” Dr. Tuisku said.

The study group included 20 eyes of 20 patients who underwent LASIK to correct high myopia, defined as 10 D or higher. The control group consisted of 10 eyes of 10 age- and gender-matched subjects, according to the abstract.

Of the study group, 55% reported experiencing more persistent symptoms of ocular discomfort, such as photophobia, irritation and foreign body sensation, than the control group. Also, LASIK patients had a significantly higher ocular surface disease score for dry eye symptoms than those in the control group, according to the study.

The LASIK patients who had postoperative symptoms of dry eye had no appreciable difference in tear production compared with controls, Dr. Tuisku said.
Surface ablation mitigates RK-induced refractive error

Laser surface ablation can safely correct refractive error associated with RK, surgeons reported in a poster presentation.

LASEK and epi-LASIK combined with a dose of mitomycin-C effectively treated refractive errors after RK with no complications, according to an AAO news release summarizing the poster.

“This gives new hope to patients who have had RK and have developed problems,” presenting author Navaneet S.C. Borisuth, MD, PhD, said in the release. “Most refractive surgeons would shy away from these patients because we were not able to deliver the results that they expected. Now, with this refinement, we can deliver a very good quality of vision for our RK patients.”

Other surgeons’ attempts to correct hyperopia with PRK or LASIK were often unsuccessful and led to complications, the release said.

In a prospective study, Dr. Borisuth and colleagues analyzed 20 eyes with hyperopic or myopic astigmatism after 8- or 16-cut RK.

After surface ablation with MMC, mean uncorrected visual acuity improved from 0.66 D ± 0.43 D to 0.4 D ± 0.15 D ( P = .0001). Best corrected visual acuity improved by two lines in seven eyes (35%) and remained unchanged in 10 eyes (50%). No patients had BCVA worse than 0.18 D, and 95.5% of patients had corrected vision within 1 D of the target refraction.

Three eyes developed haze, the authors reported.

Lenticule extraction safe, effective at 6 months

Lenticule extraction with a femtosecond laser was shown to be safe and effective, with results improving as the learning curve is overcome, a presenter said.

“We believe that this prospective study shows FLEX (femtosecond lenticule extraction) to be a safe procedure and effective,” Marcus Blum, MD, said at an event sponsored by Carl Zeiss Meditec. “The refractive outcome is acceptable for all patients and is becoming better.”

Dr. Blum presented 6-month data on the first 45 eyes treated with the technique.

“We remove the intracorneal lenticule to adjust the refractive properties of the eye so we actually have tissue removal instead of tissue ablation, and the whole success depends on the precision of the cut,” Dr. Blum said. This study was conducted using the VisuMax femtosecond system (Carl Zeiss Meditec).

The study showed that none of the patients lost two or more lines and only one lost one line after 6 months, he said, adding that 40% of patients gained one line and 14% gained two lines.

Refractively, 90% of patients were within ±1 D, but the 6-month results are not as good as the 3-month results, Dr. Blum said. When the researchers split the study group into the first 20 patients and the last 25 patients, the first 20 showed a slight shift toward hyperopia.

At 6 months, the uncorrected visual acuity in two-thirds of the patients was 20/20 or better and one patient was 20/40, he said. He added that there were no adverse effects or complications, but one patient had mild haze 6 months postoperatively.

“As you see, we are getting better. So we do have a learning curve,” Dr. Blum said. He added that stability up to now is good, but predictability analysis showed slight overcorrections in less myopic patients.

The procedure consists of four steps: processing the bottom or back of the lenticule; processing the front side of the lenticule at a depth of 120 µm to 160 µm, which overlaps the lenticule; making a side cut; and lifting the flap to remove the lenticule.

The lenticule thickness was originally targeted at 25 µm, but Dr. Blum said they are now creating 15-µm lenticules. Diameter is determined by pupil size, he added, and the studied eyes had pupils between 6 mm and 7.3 mm. Overlap between lenticule and flap averaged about 4.5 mm, and the governing ethics committee required a 300-µm stromal bed.

The study included myopes with up to 6 D of astigmatism (average of 4.5 D) and targeted refraction at –0.75 D, Dr. Blum said.

“It’s a new approach in refractive surgery,” he said.

Jennifer Morse should have my vision after Lasik. My dissatisfaction with my outcome has nothing to do with my personality, but everything to do with the miserable quality of my sight after Lasik. Her comments only serve to invalidate patients with complications, and do a disservice to all of us.

As for Ilpo S. Tuisku, MD, FEBO, he's only now figuring out what we've been reporting for years now. Big deal. What are they doing about it?