Refractive prediction accuracy of new generation IOL calculation formulas in glaucomatous and control eyes after cataract surgery.

Purpose: To compare the deviation from the target refraction after cataract surgery between glaucomatous and control eyes using a third-generation formula (SRK/T), a fourth-generation formula (Barrett Universal II), and new-generation formulas (Hill-RBF, Kane, Pearl-DGS, Hoffer QST, EVO, Cooke K6).

Materials and methods: This retrospective study included 80 eyes of 80 patients who underwent uncomplicated phacoemulsification between 2017 and 2022. Among them, 22 had primary open-angle glaucoma, 27 had pseudoexfoliative glaucoma (PEG), and 31 served as controls. Biometric measurements were obtained preoperatively, and postoperative refractions were measured with an autorefractometer. The mean follow-up was 2 years.

Results: There was no significant difference among the groups in terms of age, gender, intraocular lens (IOL) power, follow-up duration, axial length, anterior chamber depth, lens thickness, central corneal thickness, or intraocular pressure (all p > 0.05). All formulas produced a mean myopic prediction error in all three groups, with the highest deviation observed in the PEG group (mean: - 0.24 D). The smallest mean errors in all groups were with the Barrett Universal II (- 0.03 D, - 0.16 D, and - 0.07 D) and Hoffer QST (- 0.05 D, - 0.20 D, and - 0.08 D) formulas. The refractive prediction error was significantly lower for all formulas in eyes implanted with aspheric IOLs (mean: - 0.07 D) compared to spherical IOLs (mean: - 0.22 D) (p < 0.05).

Conclusion: Despite advances in IOL calculation formulas, PEG patients showed the highest prediction errors, likely due to zonular weakness. In these cases, selecting Barrett Universal II or Hoffer QST formulas may improve refractive outcomes. Aspheric IOLs also showed better prediction accuracy, though their benefit may vary with pupil size and IOL alignment.