New lenses, laser technology improving lens-based refractive surgery

Implants are safer, but physicians should do more to increase patient awareness of surgical options.

Phacoemulsification fluidics, femtosecond lasers and new IOLs are advancing lens-based refractive surgery closer to achieving the best near, intermediate and distance vision for patients.

Stephen S. Lane

However, while lens-based refractive surgery is advancing in safety and technology, many patients are unaware of the procedure, Stephen S. Lane, MD, told Ocular Surgery News.

“The results that we’ve been getting, while very good, have not been necessarily to the level of perfection that I think many people would demand before they would start to either use the technology or to recommend it or make it widely known,” he said. “With each improvement in technology and each better result that we get, the word will get out.”

Dr. Lane said that as lens technology advances toward the holy grail in lens-based refractive surgery — a lens that perfectly emulates the natural crystalline lens — patient awareness of lens-based refractive procedures should increase.

R. Bruce Wallace III, MD, said that some patients do not understand how lens-based refractive surgery improves vision, so more education about the procedure is needed. Until patients are more knowledgeable about IOL options, they will not be as likely to undergo lens-based refractive surgery or recommend it to others.

“Many of the patients who end up having lens refractive procedures come in wanting LASIK because they assumed that would take care of their problem, even if they were a hyperopic presbyope,” Dr. Wallace said.

Phaco fluidics

Surgeons need to be aware of their own perceptions of lens-based refractive surgery, Dr. Wallace said, and should extend the benefits of cataract surgery, with its safety and lens capabilities, to lens-based refractive candidates.

R. Bruce Wallace

“What’s going to be necessary for this to become mainstream surgery is for surgeons to have confidence in the systems that they’re using for cataract patients,” Dr. Wallace said. “That includes phaco equipment and pharmaceuticals. That includes intraocular lenses that produce results that they know they can see on a regular basis that are not creating a great risk.”

The enhancement of phaco technology has provided surgeons with effective means to remove and place lenses, according to the experts. Current platforms include the Stellaris Vision Enhancement System (Bausch & Lomb), a longitudinal system; Infiniti Vision System with OZil torsional handpiece (Alcon), a torsional system; and WhiteStar Signature System (Abbott Medical Optics), a transversal system.

Recent phaco fluidic innovations have enhanced lens removal, Dr. Wallace said. Good stability of the anterior segment during lens removal, without causing harm to the posterior capsule, allows for safer lens-based refractive surgery.

In addition, providing patients with good followability for both procedures allows for safer lens extraction, Dr. Wallace said.

Femtosecond laser

One of the newer potential technologies in lens-based refractive surgery is the use of femtosecond laser to assist in cataract surgery, according to Louis D. “Skip” Nichamin, MD. He said femtosecond laser, commonly used in LASIK and other refractive procedures, holds great promise for both cataract and implant surgery. Three U.S. companies are currently investigating use of femtosecond laser to assist in cataract surgery: LenSx, LensAR and Optimedica.

LenSx has received 510(k) premarket approval from the U.S. Food and Drug Administration for creation of the capsulorrhexis, Dr. Nichamin said.

Louis D. Nichamin

He has been working as a physician consultant with LensAR. The company is examining results of a “fast-cutting cool laser” to perform parts of cataract surgery that are usually performed manually, he said. Capsulorrhexis, nuclear fragmentation and incisions could all be performed with a femtosecond laser.

The laser could also have other roles in the cataract procedure, including altering the structure of a clear crystalline lens to treat presbyopia, he said.

“We are beginning to use this laser to divide the nucleus … to facilitate phacoemulsification, so that we don’t have to manually divide or chop,” Dr. Nichamin said. “The laser will actually create a pre-divided or cleaved nucleus, which we can then simply aspirate the little pieces out.”

Using femtosecond laser in cataract or lens-based surgery could potentially reduce variability in surgical procedures, he said. The laser would be able to determine the size, shape and position of the capsulorrhexis and could assist in creating the perfect capsulorrhexis to best serve the next generation of accommodating IOLs.

“In many ways, we are going to be able to utilize this technology to reproducibly perform some of the more difficult steps of the operation in an almost automated fashion,” Dr. Nichamin said. “It’s going to be more efficient, more reproducible and, most importantly, potentially safer.”

Lens options

Lens options are key to best outcomes in lens-based refractive surgery, according to Dr. Wallace. He said there are several IOLs currently in clinical trials in the U.S. that show promise for improving visual outcomes. He has been investigating the Synchrony accommodating IOL (AMO) in a clinical trial and said that if the FDA approves the lens, it could be a good addition to IOLs available as off-label options for lens-based refractive patients.

An accommodating IOL that has 6 D, 7 D or 8 D of accommodation is being developed by NuLens, according to Dr. Lane. He said the lens also shows promise for providing accommodation close to the natural lens.

Phakic IOLs are another potential option for the lens-based refractive patient. However, endothelial cell loss and other complications have been linked to angle-supported phakic lenses in Europe, and they are not often used in the U.S., he said. In 2007, two phakic lenses were withdrawn from the French market following reports of lens complications.

Additional risks linked to phakic IOLs include postoperative corneal compromise, corneal decompensation and cataracts.

But Dr. Lane said the lenses are still a viable option, especially as new phakic IOLs are developed and studied. Phakic lenses available on the U.S. market are the Visian ICL (STAAR) and Verisyse (AMO). The AcrySof Cache (Alcon) is currently in FDA trials.

“As many of these safety concerns are addressed with the design and the style of the lenses, I think that you will see more and more use of them,” Dr. Lane said. “[They will] essentially open up refractive surgery to a large segment of the ophthalmic surgeon population that is reticent to do all that is necessary to get involved in LASIK.”

Phakic IOLs can provide excellent visual results in patients with high degrees of myopia and hyperopia, he said.

“I think anybody who does phakic IOLs sees a ‘wow’ factor from their patients like no other procedure that’s done, including LASIK,” he said. “These are patients that, for the most part, are treated for relatively moderate to high myopia and who are truly incapacitated without their contact lenses and glasses [and] suddenly are glasses-free in 24 hours with no loss of quality of vision.”– by Erin L. Boyle

• Stephen S. Lane, MD, can be reached at Associated Eye Care, 2950 Curve Crest Blvd., Stillwater, MN 55082; 651-275-3000; fax: 651-275-3099; e-mail: sslane@associatedeyecare.com. Dr. Lane is a consultant and medical monitor for Alcon, a consultant for AMO and a consultant for Bausch & Lomb.
• Louis D. “Skip” Nichamin, MD, can be reached at Laurel Eye Clinic, 50 Waterford Pike, Brookville, PA 15825; 814-849-8344; fax: 814-849-7130; e-mail: nichamin@laureleye.com. Dr. Nichamin is a scientific advisor for LensAR.
• R. Bruce Wallace III, MD, can be reached at Wallace Eye Associates, 4110 Parliament Drive, Alexandria, LA 71303; 318-448-4488; fax: 318-448-9731; e-mail: rbw123@aol.com. Dr. Wallace is a consultant for Bausch & Lomb, AMO, Allergan and LensAR.