FEMTOSECOND LASER-ASSISTED VERSUS MANUAL PHACOEMULSIFICATION: ENDOTHELIAL CELL LOSS IN DENSE CATARACTS

Abstract

Introduction: Dense cataracts have represented one of the greatest challenges in ophthalmic surgery, as they hinder lens fragmentation and increase the need for ultrasonic energy during phacoemulsification—a factor directly linked to corneal endothelial damage. In this context, the introduction of femtosecond laser technology has enabled greater precision in performing incisions, capsulotomy, and nuclear fragmentation, thereby reducing intraocular manipulation and energy dissipation. However, debate persists regarding the superiority of this technology over the manual technique, particularly in cases of denser cataracts, where endothelial cell preservation is associated with maintained corneal clarity, faster visual recovery, and a lower incidence of postoperative corneal edema. This systematic literature review aimed to compare femtosecond laser-assisted phacoemulsification with manual phacoemulsification regarding endothelial cell loss in patients undergoing surgery for dense cataracts, synthesizing key scientific evidence on efficacy, safety, and clinical outcomes. Methodology: The review was conducted in accordance with PRISMA checklist recommendations, utilizing scientific articles published within the last 10 years and indexed in the PubMed, SciELO, and Web of Science databases. The following descriptors were used: "Cataract," "Phacoemulsification," "Femtosecond Laser," "Corneal Endothelium," and "Endothelial Cell Loss." Inclusion criteria encompassed studies involving patients with dense cataracts, direct comparisons between the two surgical techniques, and quantitative assessment of endothelial loss. Case reports, experimental animal studies, and research lacking specific data on endothelial outcomes were excluded. Results: Studies demonstrated that femtosecond laser-assisted phacoemulsification significantly reduced cumulative ultrasonic energy and effective phacoemulsification time, resulting in lower endothelial cell loss and reduced early corneal edema. Greater capsulotomy precision, more uniform nuclear fragmentation, improved surgical predictability, and faster initial visual recovery were also observed. However, some evidence indicated that when performed by experienced surgeons using optimized techniques, manual phacoemulsification yielded similar final visual outcomes, particularly in the long term. Conclusion: Evidence indicated that femtosecond laser-assisted phacoemulsification provided greater corneal endothelial protection in dense cataracts by reducing ultrasonic energy and intraocular trauma. Nevertheless, long-term clinical benefits appeared modest compared to the manual technique, which remained highly effective when performed by experienced surgeons. Thus, it was concluded that femtosecond technology represents a safe and potentially advantageous alternative for complex cases, although its use should take into account costs, technological availability, and patient clinical profiles.