The Benefits and Drawbacks of Femtosecond Laser-Assisted Cataract Surgery

Author: Kanclerz P, Alio JL.

Geographical coverage: Not reported

Sector: Cataract surgery

Sub-sector: Treatment benefits and drawbacks

Equity focus: Not reported

Study population: Patients with cataract

Review type: Effectiveness review

Quantitative synthesis method: Narrative synthesis

Qualitative synthesis method: Not applicable

Background

Femtosecond lasers emit ultrashort infrared pulses that disrupt tissue with high precision. This technique was initially used in corneal surgery and was later introduced into cataract surgery in 2008. It was anticipated that femtosecond laser-assisted cataract surgery (FLACS) would revolutionise cataract surgery by improving precision and minimising complications compared to traditional phacoemulsification. FLACS offers potential benefits such as a more precise capsulotomy and reduced phacoemulsification energy requirements. However, recent literature reveals that clinical outcomes and complication rates do not differ substantially between FLACS and conventional phacoemulsification cataract surgery (PCS). Despite some intraoperative advantages, the overall benefits of FLACS remain debated. Consequently, its adoption is influenced by surgical experience, case complexity, and cost-related considerations.

Objective

To review the benefits and drawbacks of FLACS compared with traditional PCS.

Main Findings

The review compared FLACS with conventional PCS across multiple clinical and surgical parameters. Advantages of FLACS: The technique demonstrated several intraoperative advantages, including a lower cumulative phacoemulsification energy. This reduced energy use is associated with less endothelial cell loss, which is particularly beneficial for patients with pre-existing corneal endothelial compromise (e.g. Fuchs’ dystrophy). Additionally, FLACS provides more precise capsulotomies, which can improve intraocular lens (IOL) centration. The technology also allows for femtosecond laser-assisted arcuate keratotomies (AKs) to correct astigmatism, although the alignment accuracy of these incisions can be variable.

Drawbacks and Complications of FLACS: Several FLACS-specific complications were noted. The incidence of anterior capsule tears is higher with FLACS (approximately 1.84% of cases, compared to 0.22% with PCS). Intraoperative miosis (pupil constriction) can occur in up to 32% of FLACS cases, and there is a risk of suction breaks during the laser docking process. There is a significant learning curve for FLACS, with complication rates decreasing as surgeons gain experience. Importantly, postoperative outcomes — including visual acuity and refractive results — were comparable between FLACS and PCS. Studies found no substantial differences between the two techniques in rates of pseudophakic cystoid macular oedema (PCME) or posterior capsule opacification (PCO).

Cost and Practical Considerations: A major limitation of FLACS is its high cost, driven by the expense of the laser systems, disposable patient interface units, and often longer surgical times. Although FLACS offers intraoperative advantages in certain complex cases (such as white cataracts or in patients with compromised corneal endothelium), its routine use is not considered cost-effective given that overall postoperative outcomes are similar to those of conventional PCS. The review concludes that while FLACS may benefit selected patient populations, it does not demonstrate universal superiority over traditional phacoemulsification.

Methodology

The literature search was conducted in PubMed and Web of Science up to 15 June 2019 to identify English-language studies on the clinical applications and outcomes of FLACS in human eyes. Reference lists of the included studies were also scanned for additional relevant publications. In addition to database searches, the authors consulted selected chapters from relevant textbooks and considered trials registered on ClinicalTrials.gov, if necessary. No efforts were made to find unpublished data. The findings from the sources were synthesised narratively.

Applicability/External Validity

The review did not explicitly discuss the applicability or external validity of its findings. However, it emphasised that FLACS is not generally cost-effective. While FLACS may benefit certain subgroups of patients, it does not show a clear overall advantage over traditional phacoemulsification in broad clinical practice. Surgeons may choose to use FLACS selectively for particular cases, but it is not justified as a routine replacement for conventional surgery given the similar outcomes and higher costs.

Geographical Focus

No geographical limits were applied to the search strategy. The review did not report the geographical distribution of the included studies, so it is unclear how globally representative the evidence base is.

Summary of Quality Assessment

Overall, there is low confidence in the review’s conclusions. On the positive side, inclusion and exclusion criteria were clearly defined, and the literature search encompassed multiple databases (with a cut-off in mid-2019). The reference lists of included studies were checked for additional references, and relevant textbook chapters and clinical trial registries were considered where appropriate. The findings were reported in a narrative format.

However, the review only included studies published in English, which introduces a language bias. The methods were not described in detail, and there was no assessment of the risk of bias of the included studies. The review did not provide lists of included or excluded studies, nor did it specify how many reviewers independently performed screening and data extraction. These methodological omissions limit the reliability of the review’s conclusions.