Issue: July 10, 2018
July 03, 2018
11 min read

Surgeons hold strong opinions for and against FLACS vs. manual cataract surgery

Issue: July 10, 2018
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Since its FDA approval in 2010, femtosecond laser-assisted cataract surgery has been an option for surgeons, a new method in their armamentarium along with the traditional manual phaco technique. However, opinions differ among surgeons regarding techniques, safety, complication rates and cost-effectiveness.

Femtosecond laser-assisted cataract surgery (FLACS) offers few disadvantages but definite refractive advantages for patients undergoing cataract surgery, OSN Cornea/External Disease Section Editor Elizabeth Yeu, MD, said.

“Really, two main differences between the two techniques, you could argue, is having that well-centered, standardized capsulotomy that the laser offers, and greater precision and predictability with laser arcuate incisions. The laser capsulotomy affects ultimate lens position and the way the capsular bag shrinks around the IOL, which is size and centration dependent,” Yeu said.

In addition to its utility in making precise capsulotomies and limbal relaxing incisions, the femtosecond laser is “extremely beneficial” for addressing dense brunescent cataracts, according to Kathryn M. Hatch, MD.

Source: Jennie L. Scott

Yeu, who uses a LenSx laser (Alcon) and a Lensar (Lensar) during her private practice procedures, noted the laser systems produce well-centered, standardized capsulotomies in nearly every cataract case. A manual capsulotomy can be smaller and a “little bit more misshapen” even when being performed in otherwise healthy eyes, in her hands, she said.

While FLACS can be used in most eyes, not all system capabilities can be used in each case, Yeu said.

“For the most part, there are not many eyes where you could not use a femto laser,” Yeu said. But, for example, Yeu would not use the corneal wound function or perform astigmatic keratotomies on patients who have undergone radial keratotomy in the past.

“These are patients I would not consider using the corneal capabilities of the femto, but I would certainly use the capsulotomy function,” she said. “Conversely, a patient with a pupil diameter that is smaller than 4.6 mm would not undergo the laser capsulotomy, but I could still utilize the femtosecond laser for the corneal wounds and the laser arcuate(s).”

Comparing outcomes

In a retrospective comparison of clinical outcomes for manual and FLACS procedures Yeu presented at the American Society of Cataract and Refractive Surgery meeting in Washington, the collected data from procedures performed by herself and Stephen Scoper, MD, showed a clear advantage for refractive and visual acuity outcomes with FLACS.

Yeu and colleagues compared outcomes of 225 eyes undergoing FLACS with a LenSx laser (after the February 2015 capsulotomy autocentration software upgrade) and 231 eyes undergoing manual cataract surgery in a retrospective chart review of otherwise healthy first eyes only undergoing uncomplicated cataract surgery.

Elizabeth Yeu

According to the review, 94.2% of eyes in the FLACS group were within 0.5 D of the target refraction compared with 83.1% of eyes in the manual group, a statistically significant difference (P < .001). Postoperatively, 53.2% of eyes in the FLACS group achieved 20/20 or better uncorrected distance visual acuity compared with 28.1% of eyes in the manual group.

Yeu and colleagues concluded in their review that FLACS appears to provide more accurate refractive outcomes and that the main difference between the two techniques may be the standardized anterior capsulotomy vs. the manual capsulorrhexis.

“Essentially, what we learned when we compared apples to apples, everything being the same minus the femtosecond laser and the manual technique, the prediction error of 0.5 D in our femto cases was 94% vs. 82% for manual,” she said.

However, there does not seem to be a consensus in published literature showing one technique being significantly advantageous over the other. Earlier this year, Thomas A. Berk, MD, and colleagues published a study in Ophthalmology evaluating postoperative outcomes for eyes undergoing FLACS compared with those undergoing manual cataract surgery.

The researchers evaluated 883 eyes undergoing manual cataract surgery and 955 undergoing FLACS. There was no statistically significant difference found between the eyes with respect to refractive and visual outcomes, according to the study.

At 3 weeks postoperative, 82.6% of eyes in the FLACS group and 78.8% of eyes in the manual group had 0.5 D or less of absolute error. Additionally, 97.1% of eyes in the FLACS group and 97.2% of eyes in the manual group had 1 D or less of absolute error, according to the study.

The researchers concluded that there was no statistically significant difference in postoperative refractive and visual outcomes for eyes undergoing manual cataract surgery or FLACS.

Manual is gold standard

Manual phaco cataract surgery is the gold standard, so any other technique needs to have a clear advantage over it, according to Steven G. Safran, MD, an ophthalmologist from Lawrenceville, New Jersey.

“It is a fantastic surgery, and for something to supplant that, it’s going to have to be better. For any new technique, this is what you’re looking for: You want it to be faster, easier, safer, less complicated and available to a wider variety of people. You want less to go wrong and fewer complications. FLACS is a step in the wrong direction for every one of those things. It’s slower, it takes longer, there are more complications, patients don’t like it as much, there is more pain, the results really aren’t as good, and there are limits as to who you can do it on. In every factor it’s worse, not better,” Safran said.


The FLACS capsulotomy is not perfect, but instead “a uniform, imperfect capsulotomy” with a serrated, not smooth, edge. The refractive benefits are not proven for FLACS, and there is more inflammation with laser-assisted surgery compared with manual surgery, Safran said.

Manual formation of the rhexis requires no energy to put into the eye whereas laser creation of the rhexis does, Safran noted. This causes release of prostaglandins and pro-inflammatory cytokines.

“It causes prostaglandin release, which makes the pupil come down, and it causes other inflammatory mediators to be released as well. It causes the pH to drop, the temperature to go up a few degrees, and then the eye sits, marinating in all of this until you go in and clean all this stuff out. Your eye is sitting in all of these inflammatory mediators you created with the laser until you take the patient into the surgical suite, go in with a phaco tip and vacuum it all out,” he said.

The results for FLACS are not superior to manual cataract surgery, Safran said, pointing to the results of a study by Sonia Manning, MD, FRCSI (Ophth), and colleagues. The study compared the results of FLACS with standard phacoemulsification cataract surgery using data from the European Society of Cataract and Refractive Surgeons multicenter European Registry of Quality Outcomes for Cataract and Refractive Surgery. The study matched 2,814 FLACS cases to 4,987 conventional cases and compared intraoperative and postoperative complications, postoperative corrected distance visual acuity and refractive outcomes.

According to the results, outcomes were similar between the two groups, and there was a statistically higher rate of prolonged postoperative corneal edema in the FLACS group (0.5%) compared with the manual group (0.1%).

“We could find no evidence to support claims that femtosecond laser-assisted cataract surgery is a major advance and better than the non-laser method. Intraoperative complications were similar and low in both groups,” the authors concluded.

David F. Chang, MD, discussed the results of Manning’s study in a published article in the Journal of Cataract and Refractive Surgery in April 2017. He noted the FLACS group in the study was comprised of “top cataract surgeons within their respective countries.”

“One might have expected this select group of experienced surgeons to have better collective outcomes when compared against the broad universe of community ophthalmologists from the ESCRS registry. However, despite being equipped with this advanced laser technology, these leading surgeons did no better (and by some parameters worse) than the registry surgeons using manual phacoemulsification in terms of surgical and postoperative complications,” he wrote in the article.


Advantages of laser

However, the precise capsulotomies and generated relaxing incisions make the laser worthwhile in many cases, OSN Technology Board Member Kathryn M. Hatch, MD, said.

The laser delivers precise location and depth for the femto-generated relaxing incisions, providing accurate and reproducible astigmatism correction for patients undergoing cataract surgery, she said.

“The other real area where the laser is extremely beneficial is for dense brunescent cataracts. The laser is able to pre-soften as well as divide the lens into quadrants, sextants or octants. This treatment may have significant impact on the degree of ultrasound energy that we use at the time of phacoemulsification,” Hatch said.

Hatch, who uses the Catalys Precision laser system (Johnson & Johnson Vision), said FLACS can hasten recovery time in patients by using less energy during the procedure. Less energy means less surgical trauma to surrounding tissue and, potentially, a faster recovery.

“When we’re doing refractive cataract surgery using toric, presbyopic intraocular lenses or astigmatism correction with limbal relaxing incisions, the femto gives you that perfectly centered, standard capsuled capsulotomy and precise incision placement. The lens centers perfectly, and it’s a very reproducible situation. I’m using femto in all cases when attempting to maximize refractive outcomes,” she said.

Differences in refractive outcomes for either technique are disputed. The initial results of the FEMCAT study, a prospective, multicenter study comparing FLACS and phacoemulsification, showed no differences between refractive outcomes.

The study included 756 eyes undergoing FLACS and 752 undergoing manual surgery. Cedric Schweitzer, MD, presented the initial findings at the ESCRS meeting in 2017.

Each surgical arm showed significant improvements in visual acuity and refraction, but there were no significant differences between FLACS and manual surgery, he said.

In his experience, FLACS offers surgeons less stress and fewer issues during a procedure, OSN Technology Section Editor William B. Trattler, MD, said, but “I recognize that not all surgeons feel the same way about this technology.”

Trattler, who uses the Lensar laser system, noted the system uses iris registration and precise 3-D imaging to accurately identify the astigmatism axis so that toric IOLs and femto astigmatic keratotomies are on the correct axis, making preop manual marking unnecessary. Postoperatively, he said he can easily verify that the toric IOL has remained at the exact axis that it was placed.

William B. Trattler

“It makes surgery a little easier for the surgeon. Less stress, less issues. I particularly like that the laser creates a grid pattern, which is like a map within the entire lens itself — I know exactly how deep I am when creating a central groove with phaco. Some patients have thicker cataracts than others. During phaco, the grid pattern/demarcation lines allow me to identify when I am at about 85% depth, at which point I crack the nucleus in half. It really makes this part of phaco efficient, as the landmarks serve as a guide. Of course, the laser is used for refractive cataract procedures, and I feel that the centered capsulotomy is helpful to achieve our final refractive target,” he said.


The Lensar laser system provides automated toric IOL planning, which is a “huge game-changing technology for me and my patients,” he said.

The system is equipped with the IntelliAxis feature, which can incorporate images taken from an Oculus Pentacam or a Cassini Total Corneal Astigmatism into the laser, Trattler said.

“We can incorporate that astigmatism axis information during the capsulotomy. Instead of making a perfect circle, the laser creates two small nubs 180° apart on the target axis, which is aligned with iris registration captured by the topography devices. It’s pretty amazing. The landmarks placed on the capsule allow me to accurately align my toric IOL so that I can confirm that the IOL is at the correct axis at the conclusion of surgery. Postoperatively, I can easily confirm that the toric axis has remained in the same position. If the toric IOL rotates postoperatively, it is very easy to identify how far the IOL has shifted. Overall, this technology saves time in toric IOL procedures, as preoperative marking of the eye is no longer necessary,” he said.

With the IntelliAxis feature of the Lensar laser system, landmarks placed on the capsule facilitate alignment of the toric IOL.

Source: William B. Trattler, MD

Proper patient selection for FLACS can improve outcomes, Trattler said. Patients who have had previous radial keratotomy, corneal scars or opacities that affect good transmission of the laser energy across the cornea to the lens may not be optimal candidates to undergo FLACS, as these opacities may result in an incomplete capsulotomy.

FLACS more time-consuming

Manual surgery is a less time-consuming technique when compared with FLACS, according to Simonetta Morselli, MD, head of the ophthalmology unit at Bassano del Grappa City Hospital, Italy.

Morselli said she performs close to 5,000 cataract surgery procedures a year, and a manual technique saves time in the operating room.

Simonetta Morselli

“I prefer manual because I work in a public hospital where I perform a large number of cataract cases, around 5,000 for each year. FLACS for us is a time-consuming technique. We must move the patient from one bed to another; some patients are less mobile patients and very old. Also, FLACS costs double that of regular cataract cases. I use FLACS only in a private cataract surgery if the patient asks me to reduce the possibility of intraoperative complications. In the hospital, I use FLACS only for complicated cases when I need fewer maneuvers to remove the cataract (for example, in a subluxated capsular bag or traumatic cataract). I like to use FLACS for premium lens implantation,” she said.

The cost to purchase a laser system and the cost to perform FLACS need to be considered as well. The laser systems are expensive and need to stay in an operating theater with a “controlled temperature,” which can be difficult in some circumstances, Morselli said.


Safran estimated that one of his manual cataract surgeries costs about $500 to $750 less per procedure when compared with a FLACS procedure. This does not consider the extra time necessary per case, maintenance for the laser or the longer operating room time necessary for FLACS.

“You can’t charge a patient extra for it, so it comes out of your premium IOL cost or it comes out of your LRI cost, and I can do LRIs with a blade. I don’t see the economic advantage of it at all. The economic advantage only comes if you convince patients it’s better. ... If a surgeon does not have the technical skill to do this without the laser, should the patient pay extra?” he said.

Opinions on manual cataract surgery and FLACS are like politics, Trattler said, with every surgeon having his or her own thoughts about which method is best. Every situation is different, and what works well for one surgeon may not be the best for another.

“I don’t need to convince every surgeon that FLACS is better because some surgeons may feel in their situation, with their own setup, that they prefer standard cataract surgery over FLACS. At our center, the laser is in the operating suite, so immediately after the laser is completed, the bed is rotated under the operating microscope, and surgery can begin following the prep and drape. Of course, it could also be about cost. At some centers, FLACS can be prohibitively expensive to provide to patients. We were fortunate that our surgery center invested in the technology when it first came out and actually purchased the laser, just like they purchased our surgical microscopes and phaco devices. So our cost to use the laser is low. This allows surgeons at our center to use FLACS routinely in patients undergoing toric and presbyopic IOL cases,” he said. – by Robert Linnehan

Disclosures: Hatch reports she received grant support from Johnson & Johnson for an industry-sponsored study on LRI nomogram technology. Morselli reports she is a consultant for Bausch + Lomb, Alcon and AcuFocus. Safran reports he is a speaker for Johnson & Johnson and Bausch + Lomb. Trattler reports he is a consultant to Lensar, Alcon, Bausch + Lomb and Johnson & Johnson and is a speaker for Bausch + Lomb and Johnson & Johnson. Yeu reports she is a consultant for Alcon and Lensar.

Click here to read the POINTCOUNTER, "Can a manual capsulotomy be as effective as a laser-assisted capsulotomy during cataract surgery?"