Corneal Biomechanical Integrity After Femtosecond Laser-Assisted Versus Manual Incisions in Cataract Surgery: A Systematic Review

Abstract

Background: The integrity of the clear corneal incision is fundamental to safety, wound sealing, and refractive stability in cataract surgery. Although femtosecond laser-assisted cataract surgery enables highly standardized, image-guided incision construction, its comparative effect on postoperative corneal biomechanical integrity remains uncertain, with individual studies reporting heterogeneous structural and functional findings. Objective: To systematically review and synthesize comparative evidence on whether femtosecond laser-assisted clear corneal incisions provide superior corneal biomechanical integrity compared with manually created clear corneal incisions in adult patients undergoing cataract surgery. Methods: A systematic review was conducted in accordance with PRISMA 2020 guidance. PubMed/MEDLINE, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials were searched for studies published between January 2015 and March 2024. Comparative clinical studies evaluating femtosecond laser-assisted versus manual clear corneal incisions and reporting corneal biomechanical outcomes were eligible. Primary outcomes included corneal hysteresis and corneal resistance factor; secondary outcomes included incision morphology, wound apposition, and wound leakage. Two reviewers independently screened studies, extracted data, and assessed methodological quality using RoB 2 for randomized trials and ROBINS-I for non-randomized studies. Owing to clinical and methodological heterogeneity, findings were synthesized narratively. Results: Eight studies involving 724 eyes met the inclusion criteria. Three studies were randomized controlled trials and five were prospective comparative cohort studies. Across all included studies, no statistically significant or clinically meaningful difference was found between femtosecond-assisted and manual incision groups in postoperative changes in corneal hysteresis or corneal resistance factor during early follow-up. In contrast, imaging-based studies consistently showed that femtosecond laser-assisted incisions had more reproducible architecture, including more regular tunnel configuration and endothelial apposition. These structural advantages did not translate into measurable superiority in global corneal biomechanical performance or clear reduction in wound-related adverse outcomes. Conclusion: Current evidence indicates that femtosecond laser-assisted clear corneal incisions offer superior morphological reproducibility but do not confer a measurable advantage over manual incisions in global postoperative corneal biomechanical integrity. Technology selection in cataract surgery should therefore not be based on an expectation of biomechanical superiority alone, and further long-term randomized studies using localized biomechanical assessment tools are warranted.