Integrating computer-assisted toric IOL implantation
Surgeon finds image registration technology helps eliminate need for axis marking
Gains in precision, efficiency
Computer-aided registration is more accurate than manual ink marks, which can themselves be several degrees wide and are dependent on the patient remaining still.
Daniel Black, MD, previously reported (at the 2015 meeting of the American Society of Cataract and Refractive Surgery) that more than 99% of his patients had ≤0.5 D of residual refractive cylinder using this system. He compared the refractive accuracy in 507 toric IOL cases with ink marking with that of a cohort of 161 eyes undergoing Callisto-guided, markerless surgery. In the ink marking group 6.0% had >0.5 D of astigmatism compared with only 0.6% in the Callisto group.1
After using the markerless toric alignment system for more than a year, I have not had any cases that failed to register successfully. Great confidence has been developed in its accuracy thanks to the postoperative results.
Computer-assisted alignment and registration have also provided important efficiency gains. Eliminating the need to take the patient to the slit lamp or use a variety of ink marking instruments has dramatically improved workflow.
Less time is also spent taking ORA measurements and making axis adjustments intraoperatively because there is a more accurate starting point. In addition, less time is spent checking and adjusting the IOL at the end of the case because the surgeon has the overlay to keep it properly aligned during viscoelastic removal.
It remains important for the toric IOL surgeon to identify the correct axis and magnitude of astigmatism preoperatively and select the correct IOL power. Once this preoperative plan is in place, the markerless toric alignment system greatly increases surgeon confidence that it can be correctly executed during surgery, with optimal visual results.
1. Black D. Evaluation of markerless alignment system for toric IOLs. Paper presented at: ASCRS/ASOA Annual Symposium & Congress; April 20, 2015; San Diego, CA