Accuracy of 11 intraocular lens power calculation formulas in short eyes.

PURPOSE: To compare the refractive prediction accuracy of 11 intraocular lens (IOL) power calculation formulas in cataract patients with short axial length (AL), and to further evaluate the predictive performance of these formulas across different AL and keratometry (Km) subgroups. METHODS: This multicenter retrospective study included 271 eyes from 271 patients with AL ≤ 22.0 mm who underwent cataract surgery at four Aier Eye Hospitals between June 2023 and March 2026. After exclusion of toric IOLs, 11 formulas were evaluated. Prediction errors were zero-centered for each formula using the overall cohort. RESULTS: Significant differences in optimized absolute prediction error were observed among the formulas (P < 0.001). EVO and Holladay 1 showed the lowest numerical MAEs (both 0.47 D), whereas Kane showed the lowest MedAE (0.36 D). In eyes with AL ≤ 21.0 mm, Haigis showed the lowest MAE and MedAE, while K6 achieved the highest proportion within ± 0.50 D. In the 21.0 < AL ≤ 21.5 mm subgroup, Kane showed the lowest MedAE, whereas EVO and PEARL-DGS achieved the highest proportions within ± 0.50 D. EVO showed the most favorable numerical performance in the 21.5 < AL ≤ 22.0 mm subgroup. CONCLUSIONS: New-generation formulas, particularly EVO and K6, demonstrated relatively favorable overall performance in Chinese cataract patients with short axial length. In eyes with AL ≤ 21.0 mm, Haigis remained highly competitive.