The results of this trial indicate that standard cataract surgery seems not to be a limiting factor for iris recognition in the large majority of cases. Some patients (5.2% in this study) might need "reenrollment" after cataract surgery. Iris recognition was primarily successful in eyes with medically dilated pupils in nearly 9 out of 10 eyes. No single case of false-positive acceptance occurred in either group in this trial. It seems therefore that iris recognition is a valid biometric method in the majority of cases after cataract surgery or after pupil dilation.

PURPOSE. Femtosecond laser-assisted cataract surgery (FLACS) is an increasingly common procedure. Most laser systems require corneal applanation and thereby increase intraocular pressure (IOP). The purpose of the present study was to evaluate the IOP changes that occur during the FLACS procedure performed using the Catalys femtosecond laser system. METHODS. IOP was measured by direct cannulation of the vitreous body of porcine cadaver eyes (N ¼ 20). By inserting a second cannula connected to a water column, all the eyes were set to a baseline IOP of 20 mm Hg. The eyes were lifted by custom-made stands to achieve the appropriate height and position under the Catalys system. The standard FLACS procedure was performed using varying fragmentation times to assess the influence of tissue fragmentation times on IOP peaks. RESULTS.We identified significant IOP elevations from baseline IOP levels during all steps of the FLACS procedure (baseline: 20.28 6 1.32 mm Hg; vacuum: 34.48 6 4.21 mm Hg; capture: 47.90 6 13.02 mm Hg; lock: 48.41 6 9.04 mm Hg; analysis: 47.15 6 5.97 mm Hg; capsulotomy: 45.74 6 6.52 mm Hg; fragmentation: 48.41 6 6.80 mm Hg; end: 17.81 6 1.61 mm Hg; all P < 0.001). Furthermore, the tissue fragmentation time had a significant effect on the peak IOP values detected (R ¼ 0.62, P ¼ 0.04, n ¼ 9).CONCLUSIONS. The present study reveals significant IOP increases during FLACS procedures carried out using the Catalys system.

Design-Computational modeling study. Methods-We propose a new approach to plan arcuate keratotomy based on personalized finite element simulations. Based on this numerical tool, an optimization algorithm was implemented to determine the incision parameters that best met the surgeon's requirements while preserving the orientation of the astigmatism. Virtual surgeries were performed on a cohort of patients to compare the performance of our simulation-based approach to results based on Lindstrom and Donnenfeld nomograms, and to intrastromal interventions. Results-Retrospective data on 28 patients showed that personalized simulation reproduces the surgically-induced change in astigmatism (Pearson correlation of 0.8). Patient specific simulation was used to examine strategies for arcuate interventions on 621 corneal topographies. Lindstrom nomograms resulted in low postsurgical astigmatism (0.03D±0.3) but frequent overcorrections (20%). Donnenfeld nomograms and intrastromal incisions showed a small amount of overcorrection (1.5%), but a wider spread in astigmatism (0.63D±0.35D and 0.48D±0.50D, respectively). In contrast, our numerical parameter optimization approach led to postoperative astigmatism values (0.40D±0.08D, 0.20D±0.08D,