Misalignment After Implantation of One-Piece Hydrophobic Toric Intraocular Lenses: Comparison Among Manufacturers and Generations

Tomohisa Nishimura,1 Keiichiro Minami2 1Mikawa Eye Clinic, Saga-city, Saga Prefecture, Japan; 2KK Evidence Slyme, Osaka City, Osaka Prefecture, JapanCorrespondence: Keiichiro Minami, KK Evidence Slyme, 1-1-1 Miyahara, Yodokaga-ku, Osaka, 532-0003, Japan, Email [email protected]: This study aimed to retrospectively compare postoperative axial misalignment of one-piece hydrophobic toric intraocular lenses (IOLs) from three manufacturers and two different generations.Methods: Clinical records of 420 eyes implanted with six types of toric IOLs were reviewed, including SN6AT3-T9 and CNW0T3-T9 (Alcon, groups SA and CNW, respectively); 355T3-T5 and XY1AT3-T6 (Hoya, groups 355 and XY1A); and ZCT150/225/300/375 and ZCW150/225/300/375 (Johnson & Johnson Surgical Vision, groups ZCT and ZCW, respectively), with 70 eyes in each group. All surgeries were performed using identical surgical equipment and technique, and axial marks were aligned using a surgical guidance system. The axial marker position was measured on postoperative day 1, and the absolute difference from the target position was calculated to determine the degree of misalignment. The rate of misalignment of ≥ 10 ° was also examined.Results: The median axial misalignments were SA = 2.3 °, CNW = 1.9 °, 355 = 3.8 °, XY1A = 3.1 °, ZCT = 4.3 °, and ZCW = 2.6 °. Misalignments in the 355 and ZCT groups were significantly greater than those in the SA and CNW groups (P < 0.045). Misalignment ≥ 10 ° was observed in 9 eyes in the 355 group, 6 eyes in the XY1A group, 10 eyes in the ZCT group, and 1 eye in the ZCW group.Conclusion: Toric IOLs from Alcon exhibited the lowest degree of misalignment. A newer-generation IOL with frost-treated haptics (ZCW group) showed reduced misalignment despite no change in material composition. This comparison suggested that IOL material and haptic properties are factors associated with misalignment.Keywords: hydrophobic acrylic toric intraocular lens, misalignment, IOL rotation