Femtosecond laser technology is gradually revolutionizing refractive
surgery, enabling surgeons to create thin LASIK flaps or remove intrastromal
tissue rather than perform excimer laser ablation.
This technology has the potential to make similar inroads in cataract
surgery, similar to how phacoemulsification supplanted extracapsular cataract
extraction 2 decades ago. Some surgeons say they can perform lens fragmentation
and create a clear corneal incision, limbal relaxing incisions and anterior
capsulorrhexis more safely and accurately with femtosecond lasers than with
established incisional and phacoemulsification methods alone.
Femtosecond laser techniques may potentially minimize complications and
improve refractive outcomes, experts say.
OSN Refractive Surgery Board Member Stephen G. Slade, MD, who recently
performed the first U.S. series of femtosecond cataract procedures with the
LenSx laser, is optimistic about the safety and efficacy of femtosecond
“I’m very enthusiastic on a number of levels,” Dr. Slade
said. “I believe that it will improve the safety and efficacy of cataract
surgery. I believe it will make cataract surgery more attractive and convenient
for patients. And it will improve our outcomes.”
“Even in its early iterations, this technology is very impressive
and successfully automates some of the most important steps of cataract
surgery: incision creation with or without astigmatic keratotomy, the
continuous curvilinear capsulotomy, and sectioning or softening the
nucleus,” David F. Chang, MD, OSN Cataract Surgery Board Member, said.
|William W. Culbertson, MD, believes that femtosecond technology
will likely boost the prominence and value of cataract surgery as a refractive
Image: Victor D
Rosa Braga-Mele, MD, FRCSC, OSN Cataract Surgery Section Editor,
elucidated the potential for femtosecond laser technology to minimize
variations in skill level and subsequent outcomes between surgeons.
“What femto is going to do is level the playing field,” Dr.
Braga-Mele said. “It’s going to allow precision and consistency for
all surgeons across the board because it will be the machine performing those
techniques. It will be easier to train residents and produce more efficient
Three laser platforms
Three femtosecond laser platforms for cataract surgery are currently in
various stages of development and regulatory approval.
LenSx Lasers has received FDA 510(k) clearance for use of its
femtosecond laser in lens fragmentation, anterior capsulotomy and corneal
Dr. Slade cited a study by Hungarian surgeon Zoltan Nagy, MD, in which
60 eyes underwent manual rhexis and 60 eyes had laser rhexis with the LenSx
laser. All laser cuts were at the exact diameter attempted, whereas only 10% of
the manual cuts achieved diametric accuracy within a tolerance of 0.25 mm.
LensAR has received a foundational U.S. patent that covers intellectual
property related to femtosecond laser technology used to increase the
flexibility of the crystalline lens to restore accommodation or facilitate lens
The company also recently received 510(k) clearance from the FDA for its
laser system to perform anterior capsulotomy in cataract surgery.
Dr. Chang is a medical monitor for clinical trials of the LensAR
femtosecond laser, and he has used the LensAR system to perform cataract
surgery in Mexico.
OptiMedica has developed a femtosecond laser with a pattern-scanning,
ultra-rapid laser and integrated optical coherence tomography imaging.
Refractive cataract surgery
Mark Packer, MD, FACS, said he envisions femtosecond cataract surgery
becoming the gold standard because of enhanced safety, accuracy and refractive
“I have no doubt that femtosecond phaco is the future of cataract
surgery,” Dr. Packer, a member of the LensAR medical advisory board, said.
“This is a premium method of performing surgery, which dovetails nicely
with the premium IOL technology, presbyopia-correcting lenses.”
As in refractive surgery, femtosecond laser technology is being adapted
in cataract surgery to improve safety and visual outcomes, according to William
W. Culbertson, MD, chairman of OptiMedica’s cataract medical advisory
“It’s basically extending the same precision, dependability
and safety of the femtosecond laser to some of the more difficult and
imprecisely performed parts of cataract surgery in an attempt to improve safety
and visual outcomes,” he said. “It’s taking a laser with its
inherent micron precision and coupling it with the dimensional imaging
capability of OCT to precisely locate where these laser spots are going to be,
and then trying to make these traditionally manually performed parts of
cataract surgery much more dependable and complication-free.”
Consequently, femtosecond technology will likely boost the prominence
and value of cataract surgery as a refractive procedure, Dr. Culbertson said.
“I think this will have an impact on premium IOLs,” he said.
“By virtue of making perfect capsulorrhexes and perfect limbal relaxing
incisions, I think it will basically be a refractive tool that is used
immediately prior to extraction of the cataract. I believe that eventually it
will become something that patients can elect to pay for that is outside the
regular third-party reimbursement for cataract surgery because it’s
refractive, regardless of whether a premium IOL is involved.”
Femtosecond cataract surgery may also enhance surgical accuracy required
for premium IOL implantation, Dr. Chang said, providing a level of precision
and consistency that few ophthalmologists can duplicate manually.
“In particular, femtosecond surgery will likely facilitate an
increase in implantation of next-generation accommodating IOLs, such as the
Synchrony (Abbott Medical Optics),” Dr. Chang said. “Optimal sizing
and centration of the capsulotomy are more critical to this dual-optic IOL in
order to constrain and control the forward-moving anterior optic.
“The ability to perform a consistently perfect continuous
curvilinear capsulotomy and to soften medium nuclei so that they can be
aspirated without ultrasound will be very appealing for refractive lens
exchange,” he said. “This will be an excellent adjunct to future
advances in accommodating IOLs in expanding the popularity and safety of
Dr. Slade echoed Dr. Chang’s observations.
“It’s very much a refractive laser,” Dr. Slade said.
“To me, that’s what is needed for premium IOL surgery. In other
words, patients are … really expecting to have excellent uncorrected
vision, so any residual refractive error needs to be dealt with.”
Incisions and lens fragmentation
Above all, femtosecond laser technology enables the surgeon to create
precise, reproducible clear corneal incisions and astigmatic relaxing
Steven G. Slade
“You can say, ‘I’m now doing a 2.8-mm incision positioned
1 mm from the limbus,’” Dr. Slade said. “To me, that’s very
exciting to be able to finally do a set that’s reproducible and then come
in with a different set and compare that. Plus, of course, you can do corneal
relaxing incisions or limbal relaxing incisions that are now of precise depth
and precise positioning.”
In femtosecond cataract surgery, lens segmentation and softening
involves pre-cutting the lens into four, six or eight pie-shaped or circular
segments that after laser softening into small cubes can be aspirated with a
0.9-mm phaco tip. This step reduces or eliminates the need for ultrasound
energy to chop nuclear material, Dr. Culbertson said.
“You don’t need to chop these segments if they’ve already
been segmented and/or softened by the laser,” he said. “You just push
them apart because there’s already a cleavage plane made by the laser down
through the lens nucleus. Then, when you push these segments apart and you
engage it in the phaco tip, they just blitz in like they’re a much softer
cataract … and then you just basically phaco-aspirate it.”
The femtosecond laser reduces phaco time and energy and further enhances
intraoperative safety. Shortened intraoperative time results in less
endothelial cell loss and reduced risk of complications, including infection,
Dr. Culbertson said.
Capsulorrhexis and IOL centration
Surgeons can use a femtosecond laser to make reproducible corneal
relaxing incisions and limbal relaxing incisions to correct astigmatism. In
addition, the technology will help take the guesswork out of centering the
capsulorrhexis and determining effective lens position, Dr. Slade said.
“It’s very much a refractive laser. We know that capsulotomy
is a factor in effective lens position. … With this, since we’re able
to control the size of the capsulotomy, I believe we’ll have much more
constant, reproducible effective lens position,” he said.
The OptiMedica femtosecond laser includes OCT.
“You basically use the OCT to image the entire anterior segment of
the eye, including the corneal diameter, corneal thickness, anterior chamber
depth and lens thickness,” Dr. Culbertson said.
OCT can also help the surgeon center the capsulorrhexis and determine
the effective lens position.
“That’s where a lot of the source of error is,” he said.
“We can extrapolate the anterior and posterior curvature of the lens to
determine where the recess of the capsular bag is. Even though it’s behind
the iris, we can mathematically extrapolate that.”
The LenSx laser also includes a fully integrated, intraoperative OCT for
LensAR has developed a customized proprietary measuring and scanning
technology based on Scheimpflug principles. It has diagnostic capabilities that
enable the characterization and placement of laser cuts in grade 4+ cataracts.
To date, grades 4 and 5 cataracts have been treated in clinical studies,
according to the company.
Dr. Braga-Mele said she is concerned about femtosecond lasers being used
to create a capsulorrhexis in cases with a small pupil.
“I can do a relatively blind capsulorrhexis under a smaller pupil,
so I don’t have to stretch a 3-mm pupil to a 5-mm pupil to perform my
capsulorrhexis,” Dr. Braga-Mele said. “I just do it underneath the
iris as a blind capsulorrhexis. I’m wondering with the femto whether
we’re going to have to enlarge all our pupils to a certain size or whether
it can create the [capsulorrhexis] underneath the iris as well.”
Dr. Chang, however, noted that the utility of using femtosecond laser
technology in challenging cases may be an equally important benefit.
“For many surgeons, the greatest advantage would be improving
outcomes with complicated cases, such as performing a [continuous curvilinear
capsulotomy] in an eye with very weak zonules or facilitating fragmentation of
an extremely dense nucleus,” he said.
Lenticular presbyopia correction
LensAR is undertaking a clinical trial outside the U.S. to determine if
its femtosecond laser can be used to soften the crystalline lens for removal or
if it can play a part in presbyopia correction, according to Dr. Slade.
“They have done a very good study of the microstructure of the
lens, and they believe that they can cut different planes within the lens and
make it where the muscles can have more of an effect than they can against an
uncut lens,” he said.
Femtosecond presbyopia correction will likely require premarket approval
by the FDA, Dr. Slade said.
“I guess the holy grail would be the ability to use the same laser
system to either treat presbyopia or to assist in cataract surgery,” Dr.
Integration of femtosecond lasers
Questions surrounding the logistics of integrating femtosecond
technology into the typical practice abound, Dr. Chang said.
“How to integrate the technology within the operating room will be
another interesting challenge,” he said. “It can certainly be used
alongside the phaco machine within the OR. However, because the femtosecond
steps can be done without creating a full- thickness incision into the eye,
another option would be to use the femtosecond laser in a separate room from
the OR. Finally, adding more elective options to the procedure will further
complicate the patient-clinician decision process, which already encompasses
the IOL type and refractive target.”
It is unclear how acquiring a femtosecond laser will affect the typical
practice in terms of price, workflow and logistics, Dr. Packer said.
“All of those things will potentially change the delivery of
surgery in ways that I don’t think we totally grasp yet,” Dr. Packer
said. “For example, the ability of this laser to make incisions and
emulsify, or at least break into little pieces, the nucleus without ever
violating the ocular surface means that it can be done in a clean environment
rather than a sterile environment. So, the laser could potentially be in a
separate room. There could be one laser room and two operating rooms, and the
patients kind of doing a round-robin between those.”
Dr. Braga-Mele said she thinks femtosecond laser technology will be
included in newer-generation phacoemulsification platforms. Combining the two
technologies in one platform would enhance economies of scale, reduce costs and
resolve logistical issues associated with having two machines, she said.
“Personally, I wouldn’t switch right now because of
that,” she said. “However, if phaco technology and newer-generation
machines are produced that have the femto technology within the machine and the
ability to have one machine even if you have two separate handpieces or
whatnot, then that would be much better because it will fit better into an OR,
it will smooth out the procedure and it will minimize the amount of time
Payment for service
For patients with private health insurance, femtosecond cataract surgery
will likely be offered as a premium service, similar to presbyopia-correcting
and toric IOLs, Dr. Packer said. However, Medicare billing for femtosecond
laser-based services is uncertain.
“I don’t yet grasp how this can be made available to the
general population Medicare patients having standard lenses,” Dr. Packer
He suggested perhaps integrating the femtosecond cataract surgery fee
into the price for premium surgery, “just like we did with the Crystalens
(Bausch + Lomb) … the toric lenses, astigmatism correction, wavefront
aberrometry, everything else.
“I just don’t see how you do that for a $600 surgeon fee and a
$1,000 facility fee,” Dr. Packer said. “Where do you pay for the
The growing number of patients adopting premium lenses may also have an
impact on fees.
Dr. Slade said he thinks that femtosecond laser purchases can fit into
the average practice’s financial scheme.
“This is a refractive cataract laser. You will use it for premium
IOL patients. If you’re willing to use a laser for LASIK, now we’re
talking about something that is 20 times the size of LASIK: cataract
surgery,” Dr. Slade said. – by Matt Hasson
How will surgeons offset
the additional expense of femtosecond lasers for cataract surgery in the
- Rosa Braga-Mele, MD, FRCSC, can be reached at 245 Danforth Ave.,
Suite 200, Toronto, Ontario, Canada M4K 1N2; 416-462-0393; fax: 416-462-3612;
- David F. Chang, MD, can be reached at Altos Eye Physicians, 762 Altos
Oaks Drive, Suite 1, Los Altos, CA 94024; 650-948-9123; fax: 650-948-0563;
e-mail: email@example.com. Dr. Chang
is a consultant and medical monitor for LensAR. He is a consultant for AMO.
- William W. Culbertson, MD, can be reached at Bascom Palmer Eye
Institute, P.O. Box 016880, Miami, FL 33101-6880; 305-326-6364; e-mail:
Culbertson is a consultant to OptiMedica and AMO.
- Mark Packer, MD, FACS, can be reached at Drs. Fine, Hoffman &
Packer, LLC, 1550 Oak St., Suite 5, Eugene, OR 97401; 541-687-2110; fax:
541-484-3883; e-mail: firstname.lastname@example.org. Dr. Packer is on the
medical advisory board for LensAR. He is a consultant for Bausch + Lomb and
Abbott Medical Optics.
- Stephen G. Slade, MD, can be reached at Slade & Baker Vision,
3900 Essex, Suite 101, Houston, TX 77027; 713-626-5544; fax: 713-626-7744;
e-mail: email@example.com. Dr. Slade
is the medical director for LenSx and owns shares.