Intraocular Lens Power Calculation Formulas Accuracy In Combined Phaco-Descemet Stripping Endothelial Keratoplasty: A 6‐Formulas Comparison Study

Published 2024 - 42nd Congress of the ESCRS

Reference: FP31.05 | Type: Free paper | DOI: 10.82333/51dc-e046

Authors: Nuno Rodrigues Alves* ¹ , Catarina Barão ¹ , Bruna Cunha ¹ , Afonso Murta ¹ , Lívio Costa ¹ , Sara Crisóstomo ¹ , Pedro Gil ¹ , Carlos Batalha ¹ , Nuno Alves ¹ , João Feijão ¹ , Vítor Maduro ¹ , Diogo Hipólito Fernandes ¹

¹Department of Ophthalmology ,Unidade Local de Saúde de São José,Lisbon,Portugal

Purpose

To assess and compare the accuracy of six modern intraocular lens (IOL) power calculation formulas in patients submitted to combined phaco-Descemet Stripping Endothelial Keratoplasty (DSAEK).

Setting

Department of Ophthalmology, Unidade Local de Saúde de São José, Lisbon, Portugal

Methods

Retrospective chart review study including patients submitted to uneventful combined phaco-DSAEK with the implantation of spherical hydrophobic monofocal IOL in-the-bag (Alcon Acrysof® AU00T0). All patients underwent optical biometry (Haag-Streit Lenstar LS-900). Refraction prediction error (PE) of each formula was calculated as the difference between the subjective refraction spherical equivalent (SE) and the targeted SE of each formula from the ESCRS IOL Calculator (Barrett Universal II, EVO 2.0, Hill-RBF, Hoffer QST, Kane and PEARL‐DGS). Outcome measures included the mean prediction error (ME), mean (MAE) and median (MedAE) absolute errors, in diopters (D), and the percentage of eyes within ± 0.25D, ± 0.50D and ± 1.00D.

Results

Twenty-four eyes with a mean axial-length of 23.01 ± 1.41 mm (mean [SD] age, 76.21 [9.9] years; 15 females [62,5%]) were included. The Kane Formula had the lowest MAE (0.618) and MedAE (0.450), followed by EVO 2.0 (MAE 0.628) and Hoffer QST (MAE 0.631). The difference in formulas absolute error was not significative (p = 0.931). In all formulas, a slight hypermetropic shift of 0.2-0.3D was observed, but it was not significantly different from zero (p > 0.05). The Kane formula, with the lowest MAE, yielded a prediction error within ± 0.25D, ± 0.50D, and ± 1.00D in 20.8%, 58.3%, and 79.2% of cases, respectively.

Conclusions

In patients undergoing combined phaco-DSAEK, our investigation revealed a non-significant hypermetropic shift of 0.2-0.3D across all studied formulas. The Kane Formula exhibited superior predictive accuracy, evident through its lowest mean absolute error (MAE), lowest median absolute error (MedAE), and the highest percentage of eyes with a PE within ± 0.50D. These results substantiate the effectiveness of advanced IOL calculation formulas, particularly the Kane Formula, in enhancing precision and optimizing outcomes for combined phaco-DSAEK procedures.