Accuracy of New-Generation Intraocular Lens Power Calculation Formulas for Highly Myopic Eyes: A Multicenter Study in Japan.

Purpose: To compare the refractive prediction accuracy of 13 intraocular lens (IOL) power calculation formulas, including seven new-generation formulas available on the European Society of Cataract and Refractive Surgeons (ESCRS) calculator, in highly myopic eyes with axial lengths (AL) of 26.0 mm or longer, through a multicenter study in Japan.

Design: A retrospective case series.

Subjects: The study included 326 eyes of 326 patients at four surgical sites in Japan.

Methods: All patients underwent comprehensive preoperative ophthalmic evaluations, including slit-lamp examination and fundoscopy by ophthalmologists. Corrected distance visual acuity and intraocular pressure were assessed by certified orthoptists. Standard phacoemulsification with intraocular lens implantation in the capsular bag was performed under topical anesthesia by experienced cataract surgeons.

Main Outcome Measures: Postoperative spherical equivalent prediction error (SEQ-PE) was assessed for 13 formulas, including traditional formulas (Haigis, Hoffer Q, Holladay 1, SRK/T, Wang-Koch (WK) adjustment formulas for Holladay 1 [Holladay 1 WK] and SRK/T [SRK/T WK]) and new-generation formulas (Barrett Universal II, EVO 2.0, Hill-RBF, Hoffer QST, Kane, Cooke K6, Pearl-DGS). Predictive performance was evaluated using root-mean-square absolute error (RMSAE) and the Eyetemis online analysis tool.

Results: The mean AL was 27.28 ± 0.98 mm. The Hoffer QST, Holladay 1 WK, and SRK/T WK demonstrated myopic shifts, whereas other formulas showed a hyperopic shift in SEQ-PE. The Haigis, Hoffer Q, and Holladay 1 exhibited relatively large hyperopic errors (≥ 0.27 D). RMSAE exceeded 0.7 in the Hoffer Q and Holladay 1, whereas the best performance (RMSAE < 0.53) was observed in the Holladay 1 WK and six new-generation formulas, except for the Pearl-DGS.

Conclusions: New-generation IOL power calculation formulas and the Holladay 1 WK offer superior predictive accuracy in highly myopic eyes compared with traditional formulas.