Femtosecond laser capsulotomy and manual continuous curvilinear capsulorrhexis parameters and their effects on intraocular lens centration

Abstract

Purpose: To measure and compare sizing and positioning parameters of femtosecond laser capsulotomy with manual continuous curvilinear capsulorrhexis (CCC).

Methods: Femtosecond capsulotomies (Alcon-LenSx Lasers Inc) and CCC were carried out in 20 eyes of 20 patients, respectively. Intraocular lens (IOL) decentration, circularity, vertical and horizontal diameters of capsulotomies, and capsule overlap were measured with Adobe Photoshop (Adobe Systems Inc) 1 week, 1 month, and 1 year after surgery. Between-group differences of parameters and predictors of IOL decentration were determined with repeated measures analysis of variance, chi-square test, and logistic regression analyses.

Results: Vertical diameter of CCC was statistically significantly higher in the first week and month. Significantly higher values of capsule overlap over 1 year and circularity in the first week showed more regular femtosecond capsulotomies. Horizontal IOL decentration was statistically significantly higher in the CCC group over 1 year. A significant difference was noted between the two groups in dichotomized horizontal decentration values at 0.4 mm with chi-square test after 1 week and 1 year (P=.035 and P=.016, respectively). In univariable general estimating equation models, type of capsulorrhexis (P<.01) and capsule overlap (P=.002) were significant predictors of horizontal decentration. Vertical diameter showed significant correlation to the overlap in the CCC group (1 week: r=-0.91; 1 month: r=-0.76, P<.01; 1 year: r=-0.62, P<.01), whereas no significant correlation was noted in the femtosecond group (P>.05).

Conclusions: More precise capsulotomy sizing and centering can be achieved with femtosecond laser. Properly sized, shaped, and centered femtosecond laser capsulotomies resulted in better overlap parameters that help maintain proper positioning of the IOL.