Accuracy of 7 artificial intelligence based intraocular lens power calculation formulas in extremely long Caucasian eyes: Short title: AI-based IOL calculation in extra-long eyes.

Purpose: To compare 7 AI-based IOL power calculation formulas in extremely long eyes DESIGN: : Retrospective accuracy and validity analysis.

Methods: SETTING: Kyiv Clinical Ophthalmology Hospital Eye Microsurgery Center, Ukraine STUDY POPULATION: : Patients with highly myopic eyes, who underwent uneventful phacoemulsification OBSERVATION PROCEDURES: Prior to cataract surgery IOL power was calculated. The power of the implanted IOL was randomly selected from the outcomes of SRK/T, Holladay 2 or Barrett Universal II. Three months after phacoemulsification, refraction was measured. Post-surgery IOL power calculations were performed utilizing the following formulas: Hill-RBF 3.0, Kane, PEARL-DGS, Ladas Super Formula AI (LSF AI), Hoffer QST, Karmona and Zhu-Lu.

Main Outcome Measures: root mean square absolute error (RMSAE), median absolute error (MedAE) and percentage of eyes with prediction error (PE) within ±0.50 D RESULTS: : Forty eight eyes with axial length exceeding 30.00 mm were studied. Hill-RBF 3.0 yielded the lowest RMSAE (0.788) with statistical superiority only over Karmona (0.956, p=0.021). In terms of MedAE, outcomes obtained by Hoffer QST (0.442) and Hill-RBF (0.490) were statistically significant vs LSF AI (0.800, p=0.013, p=0.008, respectively). The highest percentage of eyes with PE within ±0.50 D was achieved by Hill-RBF 3.0, Kane and Hoffer QST (54.17% each) statistically significant as follows: both Hill-RBF and Kane vs LSF AI (27.08%) and Karmona (39.58%), and Hoffer QST vs LSF AI.

Conclusion: All tested formulas demonstrated comparable trueness, with Hill-RBF 3.0 being more accurate than Karmona (RMSAE), and LSF AI being less accurate than Hoffer QST and Hill-RBF 3.0 (MedAE).