Femtosecond Laser-Assisted Cataract Surgery: Dead or Alive in 2025?

Femtosecond laser-assisted cataract surgery (FLACS) entered into the commercial market with much optimism, after the United States Food and Drug Administration (US FDA) approved the use of femtosecond lasers for cataract surgery in 2010.

The first available system, LenSx (Alcon Laboratories, Figure 1, above), offered surgeons a reproducible, non-invasive technique to replace the least predictable and technically most demanding steps of conventional cataract procedures.

Initial research confirmed appropriate safety and efficacy of FLACS,¹ which uses a  computer-guided laser linked to an optical imaging system (e.g. optical coherence tomography (OCT)) to perform the corneal incision, capsulotomy, and lens fragmentation steps, thus changing the requirements associated with traditional techniques by removing the need for blade incisions and reducing phacoemulsification time and energy.

However, despite the initial zealous enthusiasm, FLACS encountered a groundswell of rightful scepticism, which continues today.

With more than 250,000 cataract surgeries performed annually in Australia, and 27 million globally, cataract surgery is the most commonly performed surgical procedure.^2,3 It is hard to quantify how many of these are FLACS procedures. In the US, it is estimated that 8% of cases are FLACS,⁴ which equates to more than 300,000 surgeries per year, which is not insignificant. At WA Laser Eye Centre, FLACS is performed in 12.5% of cases and this has remained constant for the past four years.

I would describe FLACS as a labour of love. I love the technology and there are distinct advantages, the main one being it makes the surgery seamless

How Does FLACS Work?

A solid-state laser applies ultrashort laser pulses (10-15 seconds or a femtosecond) in a prescribed pattern to the cornea using a glass applanation surface in the same way laser-assisted in situ keratomileusis (LASIK) flaps or small incision lenticule extraction (SMILE) surgery is performed.

The laser causes photodisruption and plasma-induced gas bubbles along horizontal and vertical cleavage planes (Figure 3). The critical steps of cataract surgery – being the corneal incisions, capsulotomy, and lens fragmentation – are performed in just over 30 seconds. Corneal arcuate or limbal relaxing incisions are also available.

The patient then walks into the adjacent theatre for the phacoemulsification and lens insertion component of cataract surgery, which takes five to10 minutes, depending on lens/cataract density.

Why isn’t FLACS Universally Used?

I would describe FLACS as a labour of love. I love the technology and there are distinct advantages, the main one being it makes the surgery seamless. Additionally, patients’ eye movements are no longer a nuisance during the critical steps.

However, FLACs is well known not to be a cost-effective investment. The entry cost into this technology is more than AU$500,000, plus the added servicing fees. For this reason, some hospitals, day surgeries, and private practitioners are reticent to invest in it. Patients are not covered by health funds or Medicare for FLACS, so there are out-of-pocket expenses, which are considerable.

For me, purchasing the system was a gamble, but I have no regrets.

Many ophthalmologists find discussing costs uncomfortable, especially when they feel they can do as good a job manually. However, it was interesting that in a survey of delegates at the American Society of Cataract and Refractive Surgery Annual Meeting in 2014 in Boston,⁵ an overwhelming majority of ophthalmologists said they would perform FLACS if patients were rebated.

The detractors of FLACS justify their position with recent evidence suggesting there is no added benefit in terms of long-term vision outcomes.^6-8

One study found surgeons who changed from performing conventional cataract surgery (CCS) to performing FLACS had a reduction in their complication rate, regardless of their level of experience

When is FLACS Advantageous?

Lens Capsulotomy Integrity

The most difficult and critical step in the operation is performed perfectly with FLACS. Centration of the intraocular lens is guaranteed with a round, well-positioned, reproducible, and overlapping capsulotomy and carries less risk of anterior and posterior capsule opacification. A central well-sized capsulotomy ensures a reliable and effective lens position, which is vital when using premium extended depth of focus (EDOF) or multifocal intraocular lenses.

In conventional cataract surgery, the incidence of anterior capsular tears can range from 0.79% in very experienced hands to 3.8% in the general ophthalmic community.⁹ The risk is less with FLACS. Laser capsulotomy is useful in cases of high-risk trauma, pseudoexfoliation, and white cataracts.

Very shallow anterior chambers run the risk of the capsulotomy extending outwards, especially in the context of high intraocular pressure, and I have utilised FLACS in such scenarios (Figure 5).

Posterior Capsular Rupture Complication

Two prospective randomised controlled trials were published in 2019 and 2020.¹⁰ It was noted that, using current software, there was a “significant reduction in posterior capsular rupture in the femtosecond laser assisted group”.¹⁰ Posterior capsular rupture is the dreaded complication no surgeon wishes to see as it can lead to poor outcomes such as a dropped nucleus, cystoid macular oedema, and endophthalmitis.

Corneal Endothelium

Phacoemulsification and the ultrasonic energy required to remove the cataract have an adverse effect on corneal endothelium.

A seminal paper by Abell et al. showed that FLACS, when performed without corneal incisions, has less endothelial cell loss.¹¹ This is my preferred technique as it is clear that femtosecond energy applied close to and through endothelial cells will have damaging effects. Another study found less endothelial loss in patients with diabetes who underwent FLACS compared to conventional surgery.¹² Other studies have found no difference in endothelial cell loss.⁶ Despite this, most FLACS surgeons would choose laser over conventional cataract surgery in cases of Fuch’s endothelial dystrophy.

Learning Curve

One study found surgeons who changed from performing conventional cataract surgery (CCS) to performing FLACS had a reduction in their complication rate, regardless of their level of experience.¹³ A reduction in complication rate was also seen during registrar training^14,15 and when operating on post-vitrectomised eyes.¹⁶

Is FLACS Undergoing a Renaissance?

Recent software advances allow some FLACS systems to perform Corneal Allogenic Intrastromal Ring Segments (CAIRS) incisions for keratoconus treatment. This increasingly popular procedure is well suited for laser systems that are present in the hospital setting and may open a new market for its use.

In addition, a recent, unheralded change to Medicare billing legislation for incisions correcting astigmatism following anterior segment surgery (Item 42672 – usually but not only pertaining to post corneal transplantation) means this procedure, which was done with a diamond blade manually, can no longer be rebated as an outpatient procedure but only as an inpatient.

As femtosecond arcuate incisions are more accurate and predictable than manual (residual cylinder <0.5D in 90%, <0.25 in 72% post laser cuts)¹⁷ and most FLACS systems are located in inpatient settings, we will most likely see more surgeons opting for femtosecond technology to perform this procedure if the option exists.

Last, but not least, Alcon has recently acquired Lensar, a pioneer in FLACS systems. Lensar has claimed previously that its new Ally FLACS system provides a number of technological upgrades and better patient outcomes, as well as faster patient throughput that should improve its cost-effectiveness. Advances are said to include robotic operation, a smaller footprint, enhanced ergonomics, superior imaging, advanced astigmatism management tools, and a dual-pulsed laser design that reduces procedure times by as much as two-thirds.

Summary

So, is FLACS dead or alive? It is certainly not dead. Rather, it is still evolving and a useful tool in certain cases. Its role and popularity are now potentially expanding with newer procedures such as CAIRS and policy-driven Medicare changes, as well as a renewed anticipated onslaught of marketing for a more advanced robotic FLACS system (Ally). As the first source of referral, optometrists should be aware that in some cases such as pseudoexfoliation, traumatic or dense cataracts, shallow anterior chambers, and Fuch’s dystrophy, FLACS could be the better option.

FLACS should be considered as just one component of the armamentarium we use in treating cataracts. The days of surgeons telling patients that laser cataract surgery does not exist or has no role to play, are truly in the rearview mirror.

Associate Professor Rob Paul MBBS (WA) FRANZCO UWA (Allied Health) is Medical Director and lead surgeon at WA Laser Eye Centre. Recognised as Western Australia’s highest volume laser surgeon and first clinically fellowship-trained surgeon in corneal and refractive surgery (University of Toronto), his special interests are in cataract, corneal, and laser refractive surgery.

Assoc Prof Paul was a Secretary / Treasurer and Federal Counsellor for the Royal Australian and New Zealand College of Ophthalmologists (RANZCO) in WA. He is a Part 1 RANZCO Examiner in Optics, Adjunct Senior Lecturer at Curtin Medical School and Adjunct Associate Professor at the University of Western Australia School of Optometry.

He is well-published in peer reviewed journals and he mentors students, ophthalmologists, and refractive surgeons.

Assoc Prof Paul is a paid consultant for ZEISS, Johnson and Johnson, and Alcon. This article is not sponsored.

References

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4. American Society of Cataract and Refractive Surgery Annual Meeting, delegate survey, Los Angeles, United States, 5-9 May 2017.
5. American Society of Cataract and Refractive Surgery Annual Meeting, delegate survey, Boston, United States, 25-29 April 2014.
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