Toric Intraocular Lens Calculations In Eyes With Corneal Ectasia
Published 2024 - 42nd Congress of the ESCRS
Reference: FP26.01 | Type: Free paper | DOI: 10.82333/d58t-s502
Authors: Irit Bahar 1 , Olga Reitblat* 2 , Rita Zlatkin 2 , Nili Golan 2 , Uri Elbaz 3 , Lior Or 4 , Adi Einan-Lifshitz 4 , Ruti Sella 5
1Faculty of Medicine,Tel Aviv University,Tel Aviv,Israel;Rabin Medical Center,Petach Tikva,Israel, 2Rabin Medical Center,Petach Tikva,Israel;Faculty of Medicine,Tel Aviv University,Tel Aviv,Israel, 3Schneider Children's Medical Center,Petach Tikva,Israel;Faculty of Medicine,Tel Aviv University,Tel Aviv,Israel, 4Shamir Medical Center,Tzrifin,Israel;Faculty of Medicine,Tel Aviv University,Tel Aviv,Israel, 5Faculty of Medicine,Tel Aviv University,Tel Aviv,Israel;Rabin Medical Center,Petach Tikva,Israel;Mayo Clinic,Rochester,United States
Purpose
To analyze the accuracy of the astigmatism correction of toric intraocular (IOL) calculations in patients with corneal ectasia.
Setting
Rabin Medical Center Petach Tikva, Israel, and Shamir Medical Center, Tzrifin, Israel.
Methods
Consecutive patients with corneal ectasia and a regular astigmatic component, who underwent cataract extraction with implantation of a toric IOL, were retrospectively reviewed. The predicted postoperative refractive astigmatism was calculated with the Barrett True K (BTK) toric calculator using predicted and measured posterior corneal astigmatism (PPC and MPC, respectively), both with and without the Integrated K (IK) tool. In addition, the Kane toric calculator was used, with its KCN function. Based on the manifest postoperative refraction, the error in the predicted astigmatism was calculated for each method.
Results
Compared in 33 eyes of 26 patients, BTK-PCC showed the highest trimmed mean centroid prediction error for refractive astigmatism (0.29D @ 83), followed by Kane KCN (0.16D @ 76), IK-MPC (0.13D @ 11), BTK-MPC (0.11D @ 52) and IK-PPC (0.10D @ 73). While none significantly deviated from zero, BTK-PPC differed significantly from BTK-MPC (p=0.013), IK-PPC (p=0.006), and IK-MPC (p<0.001). IK-MPC led in precision and accuracy (trimmed mean 0.70D and 0.72D, respectively), but not significantly vs. IK-PPC (0.78D, 0.78D), BTK-MPC (0.82D, 0.83D), Kane KCN (0.85D, 0.86D) and BTK-PPC (0.88D, 0.91D).
Conclusions
The use of multiple measurements, provided by the IK calculator, along with BTK-MPC’s inclusion of direct posterior corneal measurement, enhanced astigmatism correction with toric IOLs in eyes with corneal ectasia. The variability in ectatic corneas likely benefits from a multi-measurement approach.