Comparison of 3 marking techniques in preoperative assessment of toric intraocular lenses using a wavefront aberrometer

Abstract

PURPOSE: To assess the accuracy of 3 corneal horizontal meridian marking techniques using the iTrace Surgical Workstation in preoperative assessment for toric intraocular lens (IOL) implantation.

SETTING: Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea.

DESIGN: Prospective comparative observational study.

METHODS: Patients were allocated into 3 groups. Three techniques-marking with a nonpendular marker with a surgeon's direct visualization, slitlamp-assisted marking with a pendulum-attached marker, and slitlamp-assisted marking with a horizontal slit beam-were used to perform the horizontal meridian marking. The marks were immediately documented and aligned with the Zaldivar toric caliper transparent topographic map. Using a horizontal reference meridian determined by the toric caliper, the accuracy of corneal horizontal marking techniques was quantitatively evaluated by determining the rotational deviation and vertical misalignment.

RESULTS: For rotational deviation, the pendular marking showed the fewest errors to the horizontal reference meridian (mean error -0.66 degrees; mean absolute error [MAE] 3.77 degrees). There was a significant difference between the pendular marking and the surgeon's direct visual marking. For the MAE, the pendular marking showed less deviation than the surgeon's direct visual marking and the horizontal slit-beam marking. With vertical misalignment, there was no significant difference between the 3 different corneal horizontal meridian marking techniques.

CONCLUSION: The slitlamp-assisted technique with the pendulum-attached marker was more precise than marking with a nonpendular marker with a surgeon's direct visualization and marking with a horizontal slit beam in preoperative assessment for toric IOLs.