Comparison of visual outcomes, alignment accuracy, and surgical time between 2 methods of corneal marking for toric intraocular lens implantation

Purpose To compare the efficacy of a computer-assisted marker system for toric intraocular lenses (IOLs) (Callisto Eye System) with manual marking techniques. Setting University Eye Hospital Munich, Ludwig-Maximilians-University, Munich, Germany. Design Prospective case series. Methods This study included patients having cataract surgery with implantation of a toric IOL (Torbi 709 M). They were randomly assigned to 1 of 2 groups based on the marking system used, manual or digital. Patients were included if they had age-related cataract and a regular corneal astigmatism of 1.25 diopters (D) or higher. Visual and refractive outcomes as well as rotational stability were evaluated. Vector analysis was performed to evaluate total astigmatic changes. Results The study comprised 57 eyes of 29 patients; there were 28 eyes in the manual group and 29 eyes in the digital group. The mean toric IOL misalignment was significantly lower in the digital group than in the manual group (2.0 degrees ± 1.86 [SD] versus 3.4 ± 2.37 degrees; P = .026). The mean deviation from the target induced astigmatism was significantly lower in the digital group (0.10 ± 0.08 D versus 0.22 ± 0.14 D; P = .008). During surgery, the mean toric IOL alignment time was significantly shorter in the digital group (37.2 ± 11.9 seconds versus 59.4 ± 15.3 seconds; P = .003). The mean overall time required to perform the surgery was significantly shorter in the digital group (727.2 ± 198.4 seconds versus 1110.0 ± 382.2 seconds; P < .001). Conclusions A digital tracking approach for toric IOL alignment was efficient and safe to improve refractive outcomes. Furthermore, image-guided surgery helped streamline the workflow in refractive cataract surgery.