PHACO vs FLACS
FLACS is newer than phaco, but is it better?
Femtosecond laser-assisted cataract surgery (FLACS) allows the automation of many critical steps of cataract extraction. The question of whether that in turn provides adequate additional benefit to the patient or surgeon to justify its considerable expense compared to standard phacoemulsification was debated at a symposium held at the 23rd Congress of the ESCRS in Athens Greece.
Dimitrios Mikropoulos MD, PhD, took standard phaco’s corner. He maintained that FLACS does not provide patients with better visual outcomes or fewer complications than standard phaco, nor does it enable surgeons to do anything that they could not do with the older technique.
A number of studies have evaluated best-corrected visual acuity and uncorrected distance visual acuity after both methods. Generally, the differences following FLACS or phaco were minimal to non-existent, said Dr Mikropoulos, OPHTHALMICA Institute, Thessaloniki, Greece.
A meta-analysis of studies comparing outcomes of FLACS and microincision cataract surgery (MICS) in 14,567 eyes detected no statistically significant differences between the two groups in terms of visually important parameters. However, the study did find that eyes in the FLACS group had significantly higher prostaglandin concentrations and significantly higher rates of posterior capsular tears (M Popovic et al. Ophthalmology 2016;123(10):2113-26.).
A European Registry of Quality Outcomes (EUREQUO) found that visual and refractive outcomes in 2,984 eyes that underwent FLACS were no better than those in 4,987 eyes that underwent phaco. Intraoperative complications were similar in the two groups but postoperative complications were more frequent in the FLACS group.
The laser has been shown to create a well-shaped and reproducible capsulotomy geometry and circularity. However, a study in which excised anterior capsules underwent scanning electron microscopy shows that the edge of femtosecond laser-created rhexes are much less smooth than after manual capsulotomy. In the same study there was a 10-fold higher incidence of anterior capsulorhexis tears (1.87% vs 0.12%) reported with FLACS compared to standard phaco (Abell et al, Ophthalmology. 2014;121(1):17-24), Dr Mikropoulos said.
In defence of FLACS, Pantelis A. Papadopoulos MD, PhD, FEBO, FEBOS-CR, argued that the technology has evolved since many of the studies comparing the procedure with conventional phaco. The studies are outdated and those comparisons may no longer hold true. They also overlook the greater ease it allows the surgeon in several stages in the cataract surgery.
“For the experienced surgeon, it adds perfection and safety to his/her surgical technique. For the inexperienced surgeon it helps him or her to proceed to the later steps of the operation without complications,” said Dr Papadopoulos, director of Ophthalmology Clinic of Athens Metropolitan Hospital, Athens, Greece.
He added that although FLACS has some contraindications, such as small pupils, corneal scars and filtration blebs, it is indicated in some of the more difficult cases, such as eyes with pseudoexfoliation, narrow anterior chamber, floppy iris syndrome and intumescent cataract.
He noted that despite the meta-analysis study showing no difference between FLACS and MICS in terms of visual outcome, there was a statistically significant difference in favour of FLACS for effective phaco time (p<0.001), capsulotomy circularity (p<0.001), postoperative central corneal thickness (p=0.02) and corneal endothelial cell reduction (p=0.006).
Dr Papadopoulos emphasised that each femtolaser machine has different pros and cons. Many of the meta-analysis studies included many cases at the learning curve of FLACS and there may be some bias in the selection of data. Moreover, the hardware and software of femtolasers are constantly evolving, he added.
He noted that adjustments of the laser spot separation and energy, improvement in the lasers’ tracker systems and the selection of a larger size for capsulotomy have reduced the initially reported higher rate of capsule complications. There are also several new applications for the femtosecond laser including posterior capsulorhexis for the prevention of posterior capsule opacification or in case of a posterior polar cataract, as well as refractive adjustment of intraocular lenses that have already been implanted.
Dimitrios Mikropoulos: firstname.lastname@example.org
Pantelis A. Papadopoulos: email@example.com