JULY 2003

Lens-based refractive surgery shifting focus from the cornea to the lens
Refractive lensectomy and phakic IOLs gain popularity as cataract and refractive surgeons see their fields merging.
Nicole Nader
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A shift in interest from cornea-based to lens-based refractive surgery has caused a stir in the ophthalmic community recently. Some say new trends in refractive surgery and the pending approvals of phakic IOLs in the U.S. market have signaled a merger of cataract and refractive surgeries.

The movement toward refractive lensectomy does not come without debate. Surgeons worldwide have amassed tremendous experience in LASIK and other cornea-based procedures. Many will not be in a hurry to abandon their expensive lasers for another method of refractive surgery.

Lens-based refractive surgery has several obvious advantages: the accuracy of IOLs, the reversibility of the procedure, the possibility of preserving accommodation in young patients and restoring it in presbyopes with accommodative IOLs, the preservation of the cornea and the short learning curve for experienced cataract surgeons.

On the other hand, lens-based surgery also carries considerable risks: the increased risk of intraocular procedures over surface or intrastromal procedures, the possibility of complications associated with IOLs, the heightened risk of retinal detachment, and with phakic IOLs, the possibility of inducing secondary glaucoma or cataract.

But experts interviewed for this article said the impact of these new alternatives goes beyond the choice of a lens-based or a cornea-based procedure for a particular patient. Surgeons predict that the increased interest in lens-based refractive surgery will ultimately lead to the fusion of cataract and refractive surgeries.

Refractive cataract surgeries
“It’s important to know how we arrived at this important juncture,” said William F. Maloney, MD, editor of the cataract and IOL section of Ocular Surgery News, associate clinical professor at the University of California, Irvine, and head of Eye Surgery Associates in Vista, Calif.

“If we plot the trajectory of innovations in cataract surgery over the past 20 years — phacoemulsification, small incisions, IOLs, advanced IOL calculations and astigmatic keratotomy among others — we see that the paradigm, or organizing principle, has been to reach a better refractive result,” Dr. Maloney said. “Every cataract surgeon who has put emphasis on their refractive result has been carrying out refractive surgery as an increasingly important component of cataract surgery.” (See related article)

Richard L. Lindstrom, MD, of Minneapolis, agreed that cataract surgery is already a refractive procedure by nature.

“Cataract surgery is a refractive surgery,” Dr. Lindstrom said. “Years ago, I coined the term ‘refractive cataract surgery’ to reflect the trend I was noticing in cataract outcomes.”

R. Bruce Wallace III, MD, clinical professor at LSU and an assistant clinical professor at Tulane, added that cataract surgery is “the most powerful refractive procedure we have.”

“It produces the most dramatic refractive result possible by any surgery to date,” Dr. Wallace said.

Dr. Maloney explained that for most of the last 2 centuries, cataract surgery was solely a lens-based extractive procedure, focusing on the visual obstruction by natural lens opacity. With phaco and the IOL, interest in refractive result grew, leading innovators to develop foldable IOLs and eventually smaller incisions and other refinements, all leading to better refractive results. Today, he said, surgical innovations have allowed cataract surgeons to address refractive error with astounding accuracy.

“Building on the remarkable success of this cataract revolution, the next phase is to eliminate the cataract from the cataract surgery equation all together,” Dr. Mal­oney said. “Step by step, our past innovations have brought us directly to this lens-based refractive procedure — corrective lens implantation or refractive lensectomy.”

Dr. Wallace agreed. “Lens procedures are part of our natural evolution,” he said. “Cataract surgery has improved so much, with more predictable outcomes, less trauma to the eye, more convenience for patients and rapid visual results. So what we are doing now is taking what we’ve learned in cataract surgery and presenting it to patients who want purely refractive procedures.”

Lens-based surgery growing
In the past 5 years, Dr. Lindstrom said he has performed 200 phakic IOL procedures in his practice. He said that phakic IOLs and other lens-based procedures are the fastest growing refractive procedures in the United States today.

“Refractive lensectomy is growing more rapidly than LASIK. Since Sept. 11, 2001, LASIK has been on the decline,” Dr. Lindstrom said. “Some visionaries say refractive lensectomy will become the most common procedure in refractive surgery.”

Many experts agree that refractive lensectomy — the removal of a natural lens and placement of a multifocal, accommodative or standard monofocal IOL with some degree of monovision — will become a common procedure for patients with high myopia.

“My belief is that we will perform wavefront-driven LASIK for patients between 1 D and 7 D of myopia, and refractive lensectomy for patients of 8 D myopia and above,” Dr. Lindstrom said.

“Where LASIK stops, lens-based procedures begin,” said Mark Packer, MD, a refractive surgeon in Eugene, Ore.

Dr. Packer’s practice, Drs. Fine, Hoffman & Packer, participated in the clinical studies of the STAAR Implantable Contact Lens, a phakic lens implanted in the posterior chamber behind the iris and in front of the natural lens.

“We had good results from this study and were extremely happy with the results, as were our patients,” he said. “I recommend phakic lenses starting in patients around 6 or 7 D of myopia. Patients with these degrees of myopia tend to have more problems after LASIK because the excimer laser ablates more corneal tissue.”

Dr. Lindstrom added, “A patient’s vision with refractive lensectomy is somewhat superior to the quality of vision with LASIK and other excimer procedures. Particularly when we can’t use wavefront-driven algorithms and we induce higher-order aberrations.”

While lens-based procedures may seem ideal for high myopes, Dr. Lindstrom pointed out that these patients make up a small fraction of the general population.

“Only about 5% or less of patients will need lens-based procedures for high myopia,” he said.

Baby-boomer mentality
What is the potential principal market for refractive lensectomy?

“Presbyopes,” Dr. Lindstrom said. “Refractive lensectomy is the only good treatment that we have for presbyopia. All the baby boomers who had LASIK in the 1990s will soon want something for their poor accommodation from distance to near.”

Dr. Packer said the baby-boomer market has a temperament that may encourage people to seek the procedure.

“The baby boomer generation has never had to wait for anything. It’s always had its way. It’s the wealthiest generation in the history of the world, and it gets what it wants,” he said. “The level of disability that the baby boomers. those aged 45 to 65, are willing to put up with has decreased, and the age at which people want cataract surgery has also decreased. People with less cataract are coming in with more complaints.”

With a large segment of the population entering presbyopia in the next 10 years, Dr. Packer said he believes refractive lensectomy will boom and, eventually, replace cataract surgery.

“Refractive lensectomy will become a precautionary procedure, which, in addition to treating presbyopia, will remove the natural lens before cataract ever develops,” he said.

Cost fuels economy
Surgeons are calculating that members of the “wealthiest generation in the history of the world” will be willing to hand over $3,000 per eye on average for elective refractive lensectomy.

“The reimbursement for refractive lensectomy is several times what Medicare pays for cataract surgery and what patients pay for LASIK. So refractive lensectomy will become very attractive to surgeons,” Dr. Lindstrom said.

“With lens-based surgeries coming around, surgeons who are interested in offering refractive modalities to patients who pay on a fee-for-service basis are going to want to be involved in technology like this,” Dr. Packer added.

“As Dr. Howard Fine proclaimed, ‘it’s a win-win-win,’ ” Dr. Wallace said. “A win for patients, a win for doctors and a win for Washington because the government won’t have to pay for cataract surgery once the time comes.”

Easy transition
“What’s more,” Dr. Wallace said, “the transition to refractive lensectomy and other lens-based procedures will be easy for many surgeons. Surgeons who are doing cataract surgery can do similar procedures to what they are already performing. They don’t have to go out and learn a whole new method. They already have the skills.”

“There are essentially no barriers to this,” Dr. Lindstrom agreed. “We all know how to take out a cataract, and it’s even easier to take out a soft, clear natural lens. So refractive lensectomy is a surgery that Americans, and surgeons in other advanced countries, are prepared to provide their patients.”

Dr. Maloney said the transition to refractive lensectomy from cataract surgery involves something more than cataract experience and skills. It requires near perfect results on a consistent basis.

“Cataract surgeons have been refractive surgeons all along. The technology is here now, and the point of recognition is here. But this doesn’t mean that every cataract surgeon has made that cross over the final threshold to refractive lensectomy,” Dr. Maloney said. “I am one who feels strongly that the transition from refractive cataract surgery to refractive lensectomy ought not be taken for granted. One must be willing to do the work necessary to further refine cataract skills. Lens-based refractive surgery is as demanding for the surgeon as it is rewarding.”

Practice makes perfect
“Every state-of-the-art cataract surgeon has the potential to be an excellent lens-based refractive surgeon, if he or she chooses to realize that potential,” Dr. Maloney said. “In order to truly deliver consistently satisfying results with this procedure, the cataract surgeon should actively prepare now by treating every cataract patient as a true refractive patient.”

“This takes more effort,” Dr. Wallace said. “The time to practice is now. Work with your cataract patients and learn the new strategies for better outcomes. It’s critical to be exact in these areas in order to satisfy patients.”

Drs. Packer and Maloney said better outcomes are in part derived from more precise measurements.

“IOL calculation is a major part of the surgery. Unfortunately, most surgeons delegate this aspect in their office,” Dr. Maloney said. “Surgeons don’t have first-hand familiarity with it anymore.”

“This is really the beginning of lens-based refractive surgery,” Dr. Packer said. “The first thing you need to know is what implants you are putting in. It’s going to depend on the formulas you use and what measurements you take.”

In his practice, Dr. Maloney has been doing his own IOL calculations for the past 5 years when refractive results are a primary goal for the patient.

“It allows you to develop an instinctive feel for the process,” he said. “This, perhaps even more than the technology involved, is important to avoid IOL calculation surprise.”

Dr. Packer advises surgeons to utilize new measuring innovations for cataract surgery, including non-contact axial length measurements and up-to-date IOL calculation formulas.

Future training
For the time being, surgeons in training are going to have to school themselves on lens-based refractive surgery techniques, Dr. Lindstrom said.

“These are skills that most doctors are going to have to pick up after graduation,” he said.

Current residency programs train ophthalmologists to do cataract surgery but not refractive lensectomy or other refractive procedures, he said.

“This is due in part to socioeconomic limitations,” Dr. Lindstrom explained. “Most universities don’t do much refractive surgery because elective procedures are done in the private sector, where people can pay out-of-pocket.”

Typical university training programs operate in a city or at a county hospital, where there may be a large welfare-based population.

“Residents are mostly doing trauma and treating cataract and strabismus,” Dr. Lindstrom said.

Unless residents take a corneal/refractive fellowship after graduation, they will likely not get meaningful training in refractive surgery.

In the future, this may change.

“The current problem of insufficient training for lens-based refractive surgery is similar to what we went through with phaco in the 1980s,” Dr. Maloney said. “There was no training in residency for several years. Surgeons had to get their training in phaco courses.”

Dr. Maloney believes that the same process will occur with lens-based refractive surgery. “It may take 5 or 10 years before this, too, will become an integral part of the training process,” he said.

One specialty of the lens
Once lens-based refractive surgery has permeated the mainstream and surgeons use the same principles for cataract surgery and refractive procedures, a final blending of cataract and refractive surgeries will occur, surgeons said.

“It will happen. It already has,” Dr. Lindstrom said. “Cataract and refractive surgeons are on their way to being one group of surgeons. More and more surgeons will develop the same set of skills. The technologies will become synergistic. We will be able to give our patients almost anything they want.”

“In the future, there will be no differentiation between cataract and refractive surgeons. We will have just lens-based surgeons,” Dr. Maloney said. “The specialties will be nearly interchangeable.”

In fact, he said, refractive lensectomy may supersede all other refractive procedures.

For Your Information:

· Richard L. Lindstrom, MD, can be reached at Minnesota Eye Consultants, 710 E 24th St, Suite 106, Minneapolis, MN 55404; (612) 813-3600; fax (612) 813-3660. Dr. Lindstrom does not have a direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.

· William F. Maloney, MD, can be reached at 2023 West Vista Way, Suite A, Vista, CA 92083; (760) 941-1400; fax: (760) 941-9643.

· Mark Packer, MD, can be reached at Drs. Fine, Hoffman & Packer Ophthalmologists, 1550 Oak St, Suite 5, Eugene, OR 97401; (541) 678-2110; fax: (541) 484-3883. Dr. Packer is a consultant for Pfizer Ophthalmics. He also receives travel support and honoraria from Carl Zeiss Meditec, Alcon, AMO and C&C Vision.

· R. Bruce Wallace III, MD, can be reached at 4110 Parliament Dr, Alexandria, LA 71303; (318) 448-4488; fax: (318) 448-9731. Dr. Wallace is a paid consultant for AMO.