Comparison of femtosecond laser-assisted cataract surgery and conventional cataract surgery: a meta-analysis and systematic review

Author: Kolb CM, Shajari M, Mathys L, Herrmann E, Petermann K, Mayer WJ, Priglinger S, Kohnen T.

Geographical coverage: Asia, Europe, Australia, and America

Sector: Cataract surgery

Sub-sector: Treatment comparison

Equity focus: Not reported

Study population: Patients with cataract

Review type: Effectiveness review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background: Cataract surgery is the leading ophthalmic operation due to the high global prevalence of cataract-related blindness. While conventional cataract surgery (CCS) is generally safe and effective, certain steps such as corneal incision, capsulotomy, and lens fragmentation remain challenging and depend heavily on surgical skills. The introduction of femtosecond laser-assisted cataract surgery (FLACS) offers a more automated approach to improve precision and reproducibility. Previous studies have reported that FLACS reduces endothelial cell loss, improves capsulotomy circularity, and lowers phacoemulsification energy use. However, the higher cost, logistical complexities, and inconsistent findings on clinical benefits are some major concerns to its widespread adoption. The existing meta-analyses show conflicting findings, hence prompting the need for comprehensive comparisons.

Objective: To compare the efficacy and safety of femtosecond laser-assisted cataract surgery (FLACS) with conventional cataract surgery (CCS).

Main findings: The review included 73 studies, 25 randomised controlled trials (RCTs) and 48 comparative cohort studies, with a total of 12,769 eyes treated with FLACS and 12,274 eyes treated with CCS. Of the included studies, 11 were conducted in Australia, 37 in Europe, 7 in America, and 17 in Asia.

Meta-analysis showed no significant difference between FLACS and CCS for uncorrected distance visual acuity (UDVA) after 1 week (P = 0.28) and at the final visit (P = 0.3). Similarly, corrected distance visual acuity (CDVA) was comparable after 1 week (P = 0.07) and 6 months or more (P = 0.12). Additionally, astigmatism induced by both procedures was comparable (P = 0.43). However, mean absolute refractive prediction error (MAE) improved with FLACS at the 1-week follow-up (P = 0.02), but differences became insignificant at later follow-ups.

In eyes treated with FLACS, UDVA, CDVA and spherical equivalent at 1 to 3 months were significantly better (P = 0.04, P = 0.005, and P = 0.007, respectively) compared to CCS. FLACS was also associated with significantly shorter total and effective phacoemulsification times (P < 0.001 for both), lower cumulative dissipated energy (P < 0.001), more precise capsulotomy circularity (P < 0.001), reduced central corneal thickness at 1 day and 1 to 3 months (P < 0.001 and P = 0.004, respectively), and less endothelial cell loss at 3 to 6 weeks and 3 months (P = 0.002 and P < 0.001, respectively).

Methodology:  The searches were conducted in PubMed, Embase, and Cochrane Library to identify clinical prospective and retrospective trials, published in English, comparing FLACS and CCS. The reference lists of included studies and relevant review articles were also scanned to identify additional relevant publications.

Two reviewers independently screened the articles, extracted the relevant data, and assessed the study quality using the Cochrane Collaboration’s risk of bias tool for RCTs and the Newcastle-Ottawa Scale for cohort studies. Disagreements between the reviewers were resolved through discussion or by contacting a third reviewer. The findings were synthesised using a fixed or random-effects model meta-analysis based on the extent of heterogeneity. Heterogeneity was assessed using the Chi-square test and I² statistics, and publication bias using a funnel. Subgroup analyses and sensitivity analyses were performed.

Applicability/external validity: The review noted that heterogeneity in study designs, surgeon experience, and cataract grades may affect real-world applicability. It also highlighted cost and logistical challenges as practical barriers to widespread FLACS adoption.

Geographic focus: The review did not apply any geographical limits. The included studies were conducted in Asia, Europe, Australia, and America.

Summary of quality assessment: Overall, there is medium confidence in the review’s conclusions. The searches were comprehensive. Inclusion and exclusion criteria were clearly defined, and two reviewers independently screened the articles, extracted data and assessed the study quality using established tools. Disagreements between the reviewers were resolved through discussion or consultation with a third reviewer. Characteristics of included studies were well-documented, meta-analyses were appropriately performed, and heterogeneity was addressed. However, the search was limited to identifying articles published in the English language only, and the review did not provide a list of excluded studies.