Rotational Stability of Intraocular Lenses: A Standardized Method for More Accurate Measurements in Future Studies
Daniel Schartmüller, Luca Schwarzenbacher, Sabine Schriefl, Veronika Röggla, Irene Steiner, Claudette Abela‐Formanek, Christina Leydolt, Rupert Menapace
Abstract
PurposeTo assess the reliability and reproducibility of a new semiautomated evaluation method, “Rotix,” for intraocular lens (IOL) rotation and to define a standardized evaluation method for future toric IOL studies.DesignReliability and reproducibility study.MethodsSetting: Department of Ophthalmology, Medical University of Vienna. Patient Population: A dataset of 25 patients with 2 consecutive follow-up visits was created to test the intra- and interrater reliability. A data test set of 10 patients including 30 pictures taken 5 minutes apart was created to test the short-term reproducibility. Intervention: Evaluation of IOL rotational stability using nontoric implants in 25 × 2 consecutive follow-up visits. Two experienced graders performed axis evaluation 3 times in a randomized order. One experienced grader performed axis evaluation for the short-term reproducibility study. Reference landmarks at the end of operation were used to assess the IOL axis. Main Outcome Measures: Intra- and interrater reliability and short-term reproducibility of axis measurements.ResultsMean standard deviation for intrarater reliability was 0.16 degrees. The intraclass correlation coefficients were 0.97 for grader 1 and 0.96 for grader 2. A very high interrater correlation of 0.95 was found. The mean individual difference between grader 1 and grader 2 was 0.061 ± 0.28 degrees. Short-term reproducibility showed a mean standard deviation of 0.22 ± 0.14 degrees.ConclusionThe novel semiautomated evaluation method showed an accurate inter- and intrarater reliability. Short-term reproducibility was below 0.25 degrees. The method of using nonmovable reference landmarks showed reliable results and should be used as a standard in future toric IOL studies. To assess the reliability and reproducibility of a new semiautomated evaluation method, “Rotix,” for intraocular lens (IOL) rotation and to define a standardized evaluation method for future toric IOL studies. Reliability and reproducibility study. Setting: Department of Ophthalmology, Medical University of Vienna. Patient Population: A dataset of 25 patients with 2 consecutive follow-up visits was created to test the intra- and interrater reliability. A data test set of 10 patients including 30 pictures taken 5 minutes apart was created to test the short-term reproducibility. Intervention: Evaluation of IOL rotational stability using nontoric implants in 25 × 2 consecutive follow-up visits. Two experienced graders performed axis evaluation 3 times in a randomized order. One experienced grader performed axis evaluation for the short-term reproducibility study. Reference landmarks at the end of operation were used to assess the IOL axis. Main Outcome Measures: Intra- and interrater reliability and short-term reproducibility of axis measurements. Mean standard deviation for intrarater reliability was 0.16 degrees. The intraclass correlation coefficients were 0.97 for grader 1 and 0.96 for grader 2. A very high interrater correlation of 0.95 was found. The mean individual difference between grader 1 and grader 2 was 0.061 ± 0.28 degrees. Short-term reproducibility showed a mean standard deviation of 0.22 ± 0.14 degrees. The novel semiautomated evaluation method showed an accurate inter- and intrarater reliability. Short-term reproducibility was below 0.25 degrees. The method of using nonmovable reference landmarks showed reliable results and should be used as a standard in future toric IOL studies.