Annual survey finds LASIK volume up more than 25%

WASHINGTON – The volume of LASIK procedures grew 26% from 2003 to 2004, according to an annual survey of practice preferences presented here at the American Society of Cataract and Refractive Surgery meeting.

Other notable findings of the survey of U.S. members of ASCRS included an overwhelming preference for acrylic IOLs, a unanimous interest in accommodating IOLs and a near-doubling of the use of clear corneal incisions from 5 years ago among the respondents.

David V. Leaming, MD, sent his annual survey on general ophthalmic trends to 6,296 physicians; 773 returned the questionnaire. He reported the results of the survey here in a presentation and a poster.

According to Dr. Leaming, in 2004, 62% of survey respondents used topical plus intracameral anesthesia in cataract surgery.

Over the 5-year period from 1999 to 2004, the use of clear corneal incisions almost doubled, from 40% to 72%, according to survey responses. Surgeons said they prefer a metal blade to a diamond blade for the cataract incision by a two-to-one ratio, Dr. Leaming reported.

As in recent years, acrylic IOLs remained the preferred IOL material among respondents, followed by silicone, PMMA and hydrogel. More than half the respondents — 57% — said they prefer a single-piece foldable IOL.

For use with ultrasmall-incision cataract surgery in the future, 38% of respondents said an acrylic lens is the most promising IOL, and 29% of respondents said an injectable lens material holds the most promise.

In a change from last year, 61% of respondents said they prefer implanting a clear IOL rather than a blue-light-filtering IOL. In 2003 47% reported preferring clear lenses.

The survey also addressed refractive surgery topics. As noted above, respondents reported an increase in LASIK volume by 26% in the year since the 2003 survey.

Seventy-five percent of respondents said 250 µm is the threshold for the residual stromal bed below which they would not perform LASIK.

Asked about what refractive procedures they were interested in adopting, 84% of respondents said they were not interested in scleral expansion, 49% were not interested in conductive keratoplasty, 54% were not interested in LASEK and 50% were not interested in phakic IOL implantation.

Respondents said they charge an average $500 additional to perform customized LASIK over their fee for conventional LASIK.

Dr. Leaming noted that in 2003 respondents said only 9% of patients were offered wavefront LASIK. In 2004, every patient was offered the option of wavefront, he said.

Regarding glaucoma, the survey posed a series of scenarios and asked what drug the respondents would prescribe. For first-line therapy in a 45-year-old patient, 60% said they would prescribe prostaglandins if the patient was blue-eyed with no cardiopulmonary complications, and 77% would prescribe prostaglandins if the patient had brown eyes and no cardiopulmonary complications. For a blue-eyed patient with a history of cardiopulmonary complications 83% would prescribe prostaglandins, and for a brown-eyed patient 94%.

Regarding medical liability, 17% of respondents said they pay a malpractice insurance premium of $10,000 per year; 14% each said they pay $7,500, $12,500 or $15,000.

IntraLase for enhancement

The IntraLase FS laser can be programmed to perform a side-cut for late LASIK enhancement that avoids some of the problems with flap lifting, said Jon G. Dishler, MD.

Dr. Dishler reported on the use of the FS laser to create a new flap in eyes undergoing enhancement at 3 to 7 years after initial LASIK surgery. He said the “side-cut only” setting on the IntraLase can create a flap deeper and smaller in diameter than the original keratectomy.

All flaps lifted easily, had smooth interfaces and healed uneventfully, Dr. Dishler said. Postoperative day 1 visual outcomes were “excellent,” he said.

“Ten years ago, we would wait about 6 months to do enhancement. Five years ago, relifting became ‘standard of care,’ but we saw a high incidence of epithelial ingrowth,” Dr. Dishler said. This new application of the FS laser allows easy access to the original, smooth corneal bed, he said.

“Centration is key” when making the new cut, he said. Dilating the pupil aids in centering the new incision because it allows the surgeon to see the old cut. Overlap of the two cuts has not been a problem, as it has been with making a second flap with mechanical microkeratomes, he said.

IntraLase lamellar keratoplasty

Lamellar keratoplasty using a femtosecond laser can be a viable alternative to penetrating keratoplasty in appropriate candidates, according to Ramòn Naranjo-Tackman, MD.

The IntraLase FS laser allows creation of both donor and recipient anterior corneal lamellae in a “clean, fast, repeatable” 35-minute procedure that has resulted in visual improvement in most eyes, Dr. Naranjo-Tackman said.

He discussed his prospective evaluation of the procedure in 16 eyes of 16 contact-lens-intolerant patients. The preoperative uncorrected visual acuity in the eyes in the study was 20/200 or worse. Postoperatively, UCVA in 75% of eyes improved by at least 2 lines of acuity, and in 50% of eyes it improved by “up to 4 lines,” he said. The 8.5-mm grafts were clear in all eyes at 3 months postop.

Dr. Naranjo-Tackman said he used eight interrupted sutures combined with an eight-point running suture in all eyes. He said more study may be needed to determine the best time for suture removal, but it probably should not be done before 6 months postop.

Among the advantages of the lamellar procedure is the preservation of the recipient’s corneal endothelium, he said.

Femtosecond vs. conventional

No statistically significant differences were seen in the outcomes of LASIK with flaps created by either a femtosecond laser microkeratome or a conventional blade microkeratome, according to Maria R. Chalita, MD.

Dr. Chalita discussed the results of a study comparing the IntraLase FS laser and the Moria M3 microkeratome. She said there were no statistically significant differences between the results with the two microkeratomes regarding postoperative best corrected visual acuity, spherical equivalent and higher-order aberrations.

Dr. Chalita compared 129 eyes that underwent wavefront-guided LASIK after flap creation with the IntraLase with 282 eyes that underwent wavefront-guided LASIK after flap creation with the Moria M3.

The differences between the two groups were minimal, she said. Both groups had increases in spherical aberration, but the difference was not statistically significant. There were also slight increases in vertical coma in the IntraLase group and horizontal coma in the Moria group, she said.

MEL 80 for myopic LASIK

A new wavefront-optimized excimer laser from Carl Zeiss Meditec is showing comparable results to other refractive lasers, and company investigators are “eagerly awaiting” final results from the laser’s clinical trials, said Steven J. Dell, MD.

Dr. Dell is an investigator in a U.S. clinical trial of the MEL 80; he and colleagues are evaluating the results of LASIK using the device in 360 eyes at five U.S. sites. Dr. Dell presented preliminary results of the trial.

Enrolled patients have myopia up to –10 D and –3.8 D of astigmatism, Dr. Dell said. the wavefront-optimized procedure is fast, with ablation taking an average of 3 seconds per diopter of correction, he said.

Early results of the study show that 93% of eyes achieved 20/20 or better for uncorrected visual acuity at 6 months; 63% achieved 20/16 or better UCVA; and 27% achieved 20/12 or better UCVA, Dr. Dell said.

In terms of safety, 6% of eyes lost one line of vision, while 34% gained one line. No patients lost two or more lines of vision, he said.

Wavefront-guided vs. -optimized

Wavefront-guided LASIK using the Allegretto Wave laser system had the same efficacy and safety profile as wavefront-optimized LASIK with the same laser in a clinical trial, but the wavefront-guided procedure induced fewer higher-order aberrations, according to results presented here.

At a symposium sponsored by laser manufacturer WaveLight, Stephen F. Brint, MD, FACS, presented results in 240 eyes that underwent either wavefront-optimized or wavefront-guided LASIK with the Allegretto Wave since September 2004. Wavefront-guided LASIK was performed in 122 of the eyes. Eyes with up to –7 D of sphere and –3 D of cylinder were randomized to receive treatment with either wavefront-optimized or wavefront-guided profiles, Dr. Brint said.

“More than 90% of patients in both groups achieved 20/20 vision without glasses or contact lenses, and more than 60% achieved 20/16 or better,” Dr. Brint said at the symposium. “For patients with few pre-existing higher-order aberrations, both platforms performed nearly identically.”

Guy M. Kezirian, MD, FACS, president of SurgiVision Regulatory Consultants Inc., the group that performed the analysis, said, “Preliminary results suggest that wavefront-guided treatments may offer certain advantages to a minority of patients with significant preoperative higher-order aberrations, such as trefoil and coma.”

A second study is underway to evaluate the safety and effectiveness of the Allegretto Wave for the treatment of mixed astigmatism, according to WaveLight.

Aberrations, visual complaints

Patients’ complaints about their vision were not related to their pupil sizes or levels of higher-order aberrations, according to a study.

Shachar Tauber, MD, administered a questionnaire to 37 patients before refractive surgery to determine whether higher-order aberrations were clinically significant across pupil sizes.

”There was no correlation between subjective visual complaints, pupil size or degree of myopia [preoperatively] and higher-order aberration measurements,” he said.

Dr. Tauber used the questionnaire to assess patients’ subjective visual complaints, and he also recorded pupil sizes and degrees of refractive error. All patients had a BCVA of at least 20/20, he said.

“We found … [that] eyes with natural super-vision (better than 20/15) had the same number of higher-order aberrations as those who had specific visual complaints,” he said.

The average pupil size was 5.9 mm in his patient group, the mean spherical equivalent was –3.74 D, and the mean root mean square of higher-order aberrations was 0.43 µm, he said.

“We could not correlate higher-order aberrations to visual differences or to night driving,” he said.

The “smallest” correlation was found between higher-order aberrations and visual complaints in patients who wore glasses and had a larger pupil diameter (greater than 6 mm) and in those who wore contact lenses but had smaller pupil diameters.

IOL removal survey

Decentration and dislocation were again the most common reasons for IOL removal in 2004, according to an annual survey of foldable IOL complications.

Nick Mamalis, MD, who conducted the survey, said these findings on decentration have been “consistent for the 7 years of our survey.”

Dr. Mamalis said that to prevent decentration and dislocation, good surgical techniques are essential, and surgeons should “make sure that the lens is well centered.”

He said the frequency of other complications depended upon what type of IOL was used.

“Ongoing vigilance is needed” regarding new IOL materials, he said.

Bag/sulcus piggyback IOLs

Placing one IOL in the capsular bag and one in the ciliary sulcus is usually the safest approach to “piggybacking” IOLs, according to Y. Ralph Chu, MD. Dr. Chu shared this and other pearls on piggyback IOL techniques at the Future Trends in Ophthalmology meeting, held during ASCRS.

“Implanting a lens in the bag and one in the sulcus prevents endothelial cell migration and protects against interlenticular opacities, which are the biggest complication of the piggyback technique,” Dr. Chu said.

Piggybacking, or using two IOLs with complementary powers to achieve optimum visual performance, is often used as a surgical strategy for patients in need of a lens power adjustment after cataract surgery and in patients who need very high lens powers, he said.

“Single high-power lenses can result in unacceptable spherical aberration, so sometimes aligning the optical centers of two IOLs with high [total] dioptric power will provide better optical results,” Dr. Chu said.

He recommended that surgeons use silicone lenses for piggybacking because they provide better resistance to interlenticular opacification. The haptics of the two lenses should be placed parallel to maintain chamber stability, he said.

The Future Trends in Ophthalmology meeting was sponsored by SLACK Inc., the publisher of Primary Care Optometry News and Ocular Surgery News, and supported by an educational grant from Advanced Medical Optics.

NSAID for cataract surgery

A new non-steroidal anti-inflammatory drug had significantly higher cure rates, lower inflammation scores and fewer treatment failures in a trial comparing it to vehicle, said investigator Stephen S. Lane, MD.

Dr. Lane discussed clinical study results with nepafenac 0.1% in a presentation at ASCRS.

“Nepafenac is a prodrug with rapid corneal penetration that converts to amfenac in the eye,” he said. According to the drug’s developer, Alcon, nepafenac is the first prodrug NSAID being developed for ophthalmic use.

Alcon, which plans to market nepafenac as Nevanac, announced during the ASCRS meeting that the Food and Drug Administration has accepted the company’s new drug application for the NSAID for the treatment of pain and inflammation associated with cataract surgery. The application has been granted priority review.

In the study presented by Dr. Lane, 476 patients were dosed with nepafenac three times daily on the day before cataract surgery, the day of surgery and for 14 days postoperatively.

The cure rate was 62.6% with nepafenac, compared with 17.2% for vehicle by the last follow-up, he said. During all postoperative visits, patients dosed with nepafenac showed a significant reduction in cells, flare and cells plus flare, he said.

“By day 1, those on nepafenac had a twofold improvement in cells and flare [over] those on vehicle,” he said.

During a question-and-answer period, Dr. Lane said he believes nepafenac may be used as a standalone drug to control inflammation in patients who cannot take steroids, but in other patients it would probably be an adjunct to steroids.

According to an Alcon press release, in clinical trials more than 80% of patients treated with Nevanac suspension were pain-free on day 1, compared with 40% to 50% in a placebo group. By day 14, approximately 95% of patients were pain-free when treated with the drug, compared with 45% to 60% of patients in the placebo group. Regarding inflammation control, more than 85% of patients treated with Nevanac suspension had no clinically significant inflammation at day 14, compared with approximately 49% of patients in the placebo group.

Accommodating IOL

An accommodating IOL produced “relatively small” objective accommodative change in clinical trials, but investigators said the level of patient satisfaction with the IOL was high.

“Patients had an objective improvement in their accommodation of about 0.6 D, but their subjective amplitude of accommodation was 2.1 D or greater,” Sunil Shah, MD, FRCS, told attendees. He presented results of a 6-month study of 65 patients implanted with the Kellan Tetraflex KH3500 lens from Lenstec.

Dr. Shah said that one patient in particular — his father — was “very happy” with his visual outcomes.

A 200-patient study of the KH3500 IOL, presented by Sanjay Mantry, MD, FRCS, found similar results.

“Patients’ subjective grading of their functional accommodation was much higher compared to objective results,” Dr. Mantry said. Patients in his study reported having a mean functional accommodation of 2.1 D, ranging up to 5 D of reported accommodation. Postoperative BCVA in the trial averaged approximately 20/25.

Deepak K. Chitkara, FRCOphth, said that 75% of patients in a 138-patient study reported being “very satisfied” with their vision after implantation with the KH3500 lens, and more than 45% of patients reported achieving functional vision that was equivalent to more than 3 D of accommodation. Uncorrected distance visual acuity of 20/40 was achieved in 70% of patients, he said.

Regarding the investigators’ observation that patients implanted with the KH3500 lens experienced little accommodative shift as measured objectively — under 1 D in most cases — but reported significant subjective improvement, Dr. Shah said, “We are a long way from seeing how these lenses actually work, but the patients continue to be happy, and that’s really what matters.”

‘Aberration-free’ IOL

An IOL designed to induce no spherical aberration in the eye has produced good visual results in patients in a preliminary study, according to a speaker here.

In a study of the Bausch & Lomb SofPort AO IOL in 105 patients, 97% of patients were happy with their visual outcome after surgery, said Louis D. Nichamin, MD.

“These patients reported as good or better than expected visual results,” Dr. Nichamin said.

Additionally, in a subset of 49 patients who were implanted with the SofPort in one eye and a conventional IOL in the fellow eye, most patients preferred the visual performance of the eye implanted with the SofPort lens, he said.

“[Other] aspheric IOLs induce negative spherical aberration to cancel out the positive spherical aberration in the eye,” he said. “But the SofPort AO Aspheric lens is aberration-free. It’s a neutral lens that doesn’t impart any asphericity.”

While a small amount of spherical aberration in the eye can be beneficial to vision by improving depth perception, Dr. Nichamin said, excessive spherical aberration can disrupt quality of vision. Standard IOLs have been found to induce positive spherical aberration (in addition to the spherical aberration that is naturally occurring in the eye). To counteract this effect, aspheric IOLs with negative spherical aberration were developed, Dr. Nichamin said. A lens with neutral spherical aberration, such as the SofPort AO, may provide similar benefit, he noted.

To “see if this technology really works,” Dr. Nichamin has begun enrollment for a 12-month randomized trial to compare the efficacy of the SofPort lens to other aspheric IOLs currently on the market.

Lifetime Achievement award

Richard L. Lindstrom, MD, received Bausch & Lomb’s Lifetime Achievement award at ASCRS. The award ceremony, held at the Ronald Reagan Building, preceded a reception in his honor featuring a performance by Motown recording artists the Temptations.

In an interview with Ocular Surgery News, Dr. Lindstrom said of this award, “One of my personal goals is to be an industry advocate. I’m a firm believer that the physician can’t do it alone, and industry can’t do it alone. I have been able to work collaboratively with industry. It’s been good to be able to get useful technology to market and to be able to help people. It’s been a positive experience.”

Dr. Lindstrom serves on the Editorial Board of Primary Care Optometry News and is Chief Medical Editor of Ocular Surgery News.

This article was also published in Ocular Surgery News, a SLACK Inc. publication.