Comparison Of Anterior Capsulotomy Edge Characteristics In Manual Continuous Curvilinear Capsulorhexis And Femtosecond Laser-Assisted Capsulotomy: A Systematic Review And Meta-Analysis

To systematically compare anterior capsulotomy edge created by manual continuous curvilinear capsulorhexis (CCC) versus femtosecond laser-assisted capsulotomy (FLACS), integrating ultrastructural (SEM/histology) findings with biomechanical and clinical safety signals.

Systematic review and meta-analysis framework of published comparative studies (manual CCC vs FLACS). Primary outcomes included capsulotomy edge microstructure (SEM/histology-derived irregularity descriptors), capsular rim biomechanics (tear strength/rim stability) and clinical anterior capsule tear events.

Databases were searched for comparative studies of CCC versus FLACS assessing capsulotomy edge morphology by SEM/histology and/or rim biomechanics and/or anterior capsule tear outcomes. Studies reporting SEM-based edge irregularity and biomechanical rim behaviour were synthesised qualitatively due to heterogeneity of measurement methods.

Across the studies, manual CCC consistently demonstrated smoother capsule edges, whereas FLACS produced microgrooves/irregularities; irregularity increased with higher energy settings in reported cohorts. Biomechanical evidence indicates differences in methods, with manual capsulotomy demonstrating superior rim stability in a dedicated biophysical comparison. Published meta-analysis evidence shows FLACS improves capsulotomy precision/circularity, while anterior capsule tear rates are not consistently different from manual CCC.

The evidence consistently supports a central, clinically relevant paradox: FLACS improves capsulotomy geometry, yet produces a more micro-irregular capsulotomy edge compared with manual CCC on histology. These edge microfeatures may contribute to capsular rim behaviour seen in biomechanical studies, even when clinical tear rates appear similar in meta-analyses. Future trials should standardise edge-quality metrics and link them to rim stability and real-world tear events across platforms and energy/interface settings.