Accuracy of eight intraocular lens power calculation formulas in patients with ciliary sulcus implantation.

Purpose: To evaluate the accuracy of intraocular lens (IOL) power calculation for ciliary sulcus-implanted IOL.

Methods: Patients with IOL (Tecnis ZA9003) implanted in the ciliary sulcus were reviewed from March 1, 2021 to November 1, 2024 at Zhongshan Ophthalmic Center, Guangzhou, China. Optic capture was used at all case. The prediction error (PE) and mean absolute error (MAE) of eight new and old formulas including Barrett Universal II (BUII), Emmetropia Verifying Optical (EVO), Haigis, Hoffer QST, Holladay 1, Kane, Radial Basis Function 3.0 (RBF 3.0), and SRK/T formula were compared. The second-generation Wang-Koch adjustment (WK2) for axial length (AL) > 26.5 mm and adjusted surgeon factor for IOL implanted in the ciliary sulcus (SF_cs) were used to modify Holladay 1 formula.

Results: 56 eyes from 56 patients were enrolled. The performance of each formula ranked by mean PE from lowest to highest were Holladay 1 (- 0.42 D), BUII (- 0.47 D), EVO (- 0.49 D), Haigis (- 0.49 D), RBF 3.0 (- 0.52 D), SRK/T (- 0.53 D), Kane (- 0.56 D), and Hoffer QST (- 0.58 D). BUII formula reached the lowest MAE (0.68 D), while Hoffer QST and Kane formula had the highest MAE (0.75 D). Holladay 1, modified with WK2 and a SF_sc of 1.37, achieved a mean PE of 0 ± 0.67 D, the lowest MAE (0.52) and MedAE (0.40), as well as the highest percentage of eyes with PE within ± 0.25 D, ± 0.50 D, and ± 1.00 D.

Conclusion: Among the eight included formulas, Holladay 1 formula modified with WK2 adjustment and a SF_cs of 1.37 was recommended for patients with sulcus-implanted optic-captured ZA9003 IOL.