Histological comparison between the anterior capsule integrity in femtosecond laser-assisted capsulotomy and traditional continuous curvilinear capsulotomy in cataract surgeries

Purpose
To compare the histological edge structures of anterior lens capsule specimens obtained from laser-assisted cataract surgery capsulotomies using two different laser platforms (LenSx post-soft-fit and Victus II) with that of traditional continuous curvilinear capsulorhexis (CCC) using scanning electron microscopy (SEM).
Setting
I-Care Center, Alex Eye Center, Faculty of Medicine, Alexandria University, Alexandria, Egypt.
Design
Prospective comparative series.
Patients and methods
Anterior capsule specimens following CCC (=15) or femtosecond laser-assisted capsulotomy using two platforms (LenSx, =15 and Victus, =15) were studied by SEM. Irregularity of the capsule edge was quantified using two parameters (angular second moment and contrast) using ImageJ software. The clinical features and laser parameters were correlated with angular second moment and contrast. SEM images were analyzed for the coefficient of variation (CoV) of pixilation along the capsule edge and homogeneity using gray-level co-occurrence matrix analysis. Subjective analysis for cut-surface irregularities and assessment for complications and anomalies, such as tags and misdirected laser shots, were also made.
Results
The femtosecond laser-assisted capsulotomy edge surfaces created by both laser platforms showed marked irregularity compared with the smoother edge of the CCC. The angular second moment and contrast measures for both lasers differed significantly from those obtained for CCC (<0.001). There was little between-laser difference in angular second moment and contrast measures. The mean CoV values from the regression analysis showed the manual edge (16.47%) was smoother than the edges created with LenSx post-soft-fit (20.88%) and Victus II (23.04%) platforms. In the manual group, there is dishomogeneous thickness along the capsulorhexis edge, while in the femtosecond laser samples; the cuts are more homogeneous in thickness throughout the whole capsulorhexis edge. Tags occurred with a mean of 4. Misdirected pulses were seen with Victus II (5/15) cases.
Conclusion
Laser capsulotomies are approaching the smoothness of manual capsulorhexis. The LenSx post-soft-fit platform shows less anomalies and smaller difference for the CoV and homogeneity metrics compared with the Victus II platform. In the manual group, there is dishomogeneous thickness along the capsulorhexis edge, while in the femtosecond laser samples the cuts are more homogeneous regarding thickness throughout the whole capsulorhexis edge.