Typically the Zeiss Callisto eye alignment system is used to assist with orientation of a toric IOL. In today’s case, shared by guest surgeon Dr. Thada Tantisarasart, the Callisto is used to guide the location of needle tracks used to perform a Yamane technique for flanged intrascleral haptic fixation of a 3-piece IOL. It’s an interesting alternative to using a toric marker and we want to thank Dr. Tantisarasart for sharing this case!
Here are some additional surgical notes from Dr. Tantisarasart: In this particular case, the Callisto system was not only used to align the scleral tunnel entry sites, but I also utilized the limbal relaxing incision alignment (green overlay) to guide the trajectory of the needles, ensuring both tunnels were symmetrically angled. This visual cue helped me achieve equal tunnel length and angulation, enhancing IOL centration.
Specifically, the trajectory was set to form a 20-degree angle relative to the limbus, mirroring the function of the Yamane needle stabilizer, which is designed to maintain the needle at a 20-degree horizontal angle. This approach helped achieve symmetrical tunnel geometry and improved centration of the IOL.
To objectively confirm the centration, we performed anterior segment OCT, which showed that the IOL tilt was less than 5 degrees in both the vertical and horizontal axes.
