The following is a summary of “Comparison of two digital alignment systems for toric intraocular lens implantation,” published in the September 2024 issue of Ophthalmology by Zeilinger et al.
Researchers conducted a retrospective study to compare the precision, repeatability, and loss of track between the 2 mostly used digital alignment systems.
They examined 15 individual’s eyes over 21 years old with cataracts. The 2 systems were superimposed and recorded during the procedure, and the alignment of the 2 displayed alignment axes was analyzed for precision, repeatability, and loss of tracking.
The results showed a difference in precision and repeatability between the 2 digital alignment systems concerning the projected alignment axis. The deviation from the actual target axis was notably different, with a mean of 0.34° ± 0.75° for the Zeiss system and 1.60° ± 1.08° for the Alcon system (P = 0.03, n = 14). The within-subject standard deviation was significantly lower at 0.21° for the Zeiss system compared to 0.34° for the Alcon system (P = 0.03, n = 14).
Investigators concluded that the Zeiss Callisto system exhibited a lower deviation from the target axis, greater stability with eye movements, and reduced need for microscope illumination compared to the Alcon system, while both the systems showed high precision relative to manual marking methods.