Capsulotomy morphology in cataract surgery: comparison of five femtosecond lasers.

PURPOSE: To compare the capsulotomy rim morphology of anterior lens capsules obtained by 5 femtosecond laser-assisted cataract surgery (FLACS) platforms: Catalys, FEMTO LDV Z8, LensAR, LenSx, and Victus.

SETTING

University of Basel, Basel, Switzerland.

DESIGN

Experimental study.

METHODS

Anterior lens capsules from 6 interventions per laser platform were collected (N = 30). 4 of each were assessed under light microscopy (LM; n = 20), and 2 were assessed under scanning electron microscopy (n = 10). A qualitative evaluation of all samples was conducted, as well as a semiquantitative analysis of the extent of irregularities present in LM samples. The Dunn multiple comparisons test was conducted to determine which lasers produced significantly smoother capsulotomies.

RESULTS

Irregularities along the lens capsule rim were observed in all samples. Distinct irregularities were observed for Catalys (unconnected laser pulses bordering the capsulotomy), FEMTO LDV Z8 (numerous additional rows of laser pulses), and LensAR (at least one section with multiple rows of laser pulses). Victus demonstrated a significantly higher degree of smoothness of capsulotomy (median = 306 degrees) compared with Catalys (median = 171 degrees) ( P = .02). The medians for other laser platforms fell between these values.

CONCLUSIONS

Different laser platforms produce morphologically and quantitatively distinct irregularities, which may influence capsulotomy strength differently. FEMTO LDV Z8, a low-energy laser, did not produce a smoother capsulotomy than the high-energy lasers. Our results suggest that, with current technologies, the precision of the laser is more important than the pulse energy in determining the regularity of the capsulotomy surface.