Laser refractive cataract surgery: Benefits in eye of beholder

May 15, 2014

Controversy continues over whether the femtosecond laser provides advantages in cataract surgery that justify its added cost.

 

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Controversy continues over whether the femtosecond laser provides advantages in cataract surgery that justify its added cost.

 

By Cheryl Guttman Krader; Reviewed by Steve Arshinoff, MD, and Barry Seibel, MD

As the number of published studies investigating laser refractive cataract surgery (LRCS) grows, the information they provide is fueling an ongoing debate about the role of this new procedure.

Steve A. Arshinoff, MD, explained why he still prefers conventional phacoemulsification, while Barry Seibel, MD, explained the reasons underlying his transition to LRCS.

Dr. Arshinoff explained his viewpoint on LRCS with reference to the evolutionary concept of the “non-zero sum.” The idea, as stated by Robert Wright, is that the world tends to amalgamations in endlessly increasing complexity, as long as the sum of benefits to the amalgamating parties exceeds zero.

Against those terms, Dr. Arshinoff questioned whether the results with LRCS are better than those achieved in the hands of an excellent surgeon, or if instead, LRCS simply introduces different risks and at the same time may severely limit the potential market.

For perspective, Dr. Arshinoff contrasted LRCS with previous innovations in ophthalmology, including IOLs, ophthalmic viscosurgical devices, phacoemulsification, limbal relaxing incisions, and toric and multifocal IOLs, each of which might be considered a true advance for bringing forth novel and distinct advantages.

 

However, he contended the same cannot be said for femtosecond lasers in cataract surgery.

“It is clear to me that there is an advantage of using the laser to soften the lens and thereby reduce phaco energy use, especially in eyes with dense cataracts,” said Dr. Arshinoff, clinical instructor, Department of Ophthalmology, University of Toronto, Ontario, and adjunct assistant clinical professor of ophthalmology, McMaster University, Hamilton, Ontario. “However, whether the laser is better for capsulotomy and making the cataract incisions is still debatable considering reports of increased capsule tears with laser capsulotomies and laser surgical incisions that don’t seal as well as those made with diamond knives.

“Furthermore, while the refractive predictability may be better using the laser for LRIs, surgeons can easily adjust the outcome of a manual procedure at the slit lamp,” he said.

Considering his current experience with simultaneous bilateral cataract surgery, he believes it is unlikely he could achieve better outcomes transitioning to LRCS, he noted.

“Phaco allows me to perform bilateral cataract surgery on just about any patient, with correction of presbyopia and astigmatism as needed and with minimal risk,” Dr. Arshinoff said. “And, in just 30 minutes, both eyes are done, and patients immediately have good vision.”

 

Dr. Arshinoff also disputed the idea that use of the femtosecond laser will improve predictability of effective lens position (ELP) and therefore refractive accuracy predictability, noting that he believes the real problems limiting better refractive outcomes stem from the methods currently used for measuring corneal refractive power, as well as ELP.

Discussing economic issues, Dr. Arshinoff pointed out that the cost of phacoemulsification makes it accessible almost everywhere except perhaps for the poorest countries. In contrast, authors of a recently published analysis of the costs and benefits of LRCS concluded the procedure was not cost-effective [Ophthalmology. 2014;121:10-16].

“According to current benchmarks, any intervention costing more than $60,000 per quality-adjusted life year (QALY) gained is considered to be hopeless in terms of eventually succeeding, and in this published analysis from Australia, the QALYs gained with LRCS was almost $93,000 Australian dollars (AUD; ~$86,000 US dollars)/QALY,” he said.

“LRCS did become cost-effective in the best case scenario assuming 100% perfect outcomes with zero complications and a cost to the patient of only $300 rather than the current usual $1000, resulting in each QALY gained costing $20,000 AUD,” Dr. Arshinoff said. “However, that is still a huge difference compared to standard phaco, which costs $4,378 AUD/QALY gained.”

 

Dr. Arshinoff also raised concern that the introduction of LRCS is a giant step toward removing the “art” of cataract surgery and making it more of a commercial commodity in which the resources and financial control of medicine are taken out of the hands of the physicians and placed under corporate control.

“If you look at what has happened to our ‘art’ in the past decade, we can identify a number of examples of where the services we’ve provided have passed into the hands of companies or other groups,” he said. “The net result will be a decrease in income for our heirs and an increase in corporate control and income.”

Based on his current assessment of the technology and costs, Dr. Arshinoff proposed that the cataract surgery market will be divided three ways. Small incision extracapsular extraction will be the mainstay in underdeveloped areas of India, Africa, and southeast Asia, while phacoemulsification will dominate in modernizing third world countries and in Canada and other countries where socialized medicine exists. LRCS will find a role in private American and Western societies, but perhaps mostly in the realm of corporate centers where surgeons will be forced to use the laser and other machines or watch as the procedures are performed by technicians.

Despite his concerns, Dr. Arshinoff acknowledged that use of the femtosecond laser is likely to expand, and looking to the future, he expressed a few hopes.

“I hope that LRCS will become easier so that the entire procedure can be performed under the same microscope and will make the surgery time shorter, not longer,” he said. “I also hope the equipment will become more maneuverable so that it is adaptable to remote areas, and that it will become reasonably cheap and make me feel like I am providing some added quality and increasing my art in surgery, not taking away from it.”

 

Attributes translate into advantages

Dr. Seibel acknowledged that it is possible to do good cataract surgery without using the femtosecond laser. However, he contended that by incorporating the femtosecond laser, cataract surgery is unquestionably better.

“The technology is here to stay because of its attributes, and it is growing and developing. I see the femtosecond laser as an empowering technology,” said Dr. Seibel, clinical assistant professor of ophthalmology, Geffen School of Medicine, University of California Los Angeles.

Dr. Seibel briefly reviewed published data supporting the advantages of using the laser for capsulotomy, lens fragmentation, corneal incisions, and relaxing incisions. He noted that capsulotomies made with the laser are more regularly shaped, centered, and stronger so that there is less likelihood for radial extension than with a manual capsulorhexis.

Use of the laser for lens fragmentation has enabled reduction in phaco energy use and may thereby also minimize the risk for incisional burns, he said.

“These advantages of the laser are expected considering that the technology was specifically designed to address surgical steps that are the least predictable and perhaps most likely to cause problems when performed manually,” Dr. Seibel said.

 

Dr. Seibel acknowledged that LRCS involves extra time, particularly from positioning the patient. However, there is also some offset in time needed to complete other steps (e.g., shorter time for laser versus manual capsulotomy), and any net increase in length of the procedure is nominal and not bothersome to patients.

As another benefit, use of the laser enhances visualization.

“There is a trend in surgery toward the development of technology that not only provides more accurate control but also improves visualization,” Dr. Seibel said. “With the imaging capabilities of the femtosecond laser, surgeons can now map a safe zone to protect ocular structures from unwanted exposure to laser energy, and one commercially available system (Catalys, Abbott Medical Optics) can extrapolate the anterior and posterior capsule margins to the perimeter of the bag.

“This capability enables the capsulotomy to be centered on the scanned capsular bag,” he said. “As a result, effective lens position should be more predictable because the haptics should extend to the perimeters of the capsule and the optic edge should be concentrically overlapped by the capsulotomy rim.”

Addressing Dr. Arshinoff’s reference to the art of cataract surgery, Dr. Seibel suggested the focus should be on science. As an analogy to explain his point, he showed pictures of home-made chocolate chip cookies and the wheels of a commercial jetliner. Whereas the irregular edges of the cookies added a certain appetizing appeal, Dr. Seibel noted that precise roundness is wanted for proper functioning of the landing wheels.

 

“A similar comparison can be made between a manual capsulorhexis and a laser-created capsulotomy. Images from a series of eyes with a manual capsulorhexis reveal variations in appearance indicative of an art form, but with use of the laser, the capsulotomies are perfectly circular every time,” he said.

 

Steve Arshinoff, MD

E: ifix2is@sympatico.ca

Dr. Arshinoff is a consultant to Abbott Medical Optics, Alcon Laboratories, and Bausch + Lomb.

Barry Seibel, MD

E: idoc2020@me.com

Dr. Seibel is a consultant to and holds stock in OptiMedica. He is a speaker for Abbott Medical Optics and is a certified user for the LenSx, LensAR, and Catalys femtosecond laser systems.