ESCRS - FPM08.10 - Intraocular Lens Power Calculation After Previous Laser Vision Correction: Formula Comparison

Intraocular Lens Power Calculation After Previous Laser Vision Correction: Formula Comparison

Published 2022 - 40th Congress of the ESCRS

Reference: FPM08.10 | Type: Free paper | DOI: 10.82333/f9j0-xm94

Authors: Raquel Félix* 1 , João Bernardes 2 , Maria Silva 3 , Miguel Raimundo 4 , Joaquim Murta 4

1Department of Ophthalmology,Centro Hospitalar e Universitário de Coimbra (CHUC),Coimbra,Portugal, 2Department of Ophthalmology,Centro Hospitalar e Universitário de Coimbra (CHUC),Coimbra,Portugal;Faculdade de Medicina da Universidade de Coimbra (FMUC),Coimbra,Portugal, 3Unidade de Oftalmologia de Coimbra (UOC),Coimbra,Portugal, 4Department of Ophthalmology,Centro Hospitalar e Universitário de Coimbra (CHUC),Coimbra,Portugal;Faculdade de Medicina da Universidade de Coimbra (FMUC),Coimbra,Portugal;Unidade de Oftalmologia de Coimbra (UOC),Coimbra,Portugal

Purpose

To evaluate the accuracy of modern and established formulas for intraocular lens (IOL) power calculation in eyes that have previously undergone myopic or hyperopic laser in situ keratomileusis vision correction.

Setting

Single center study, set in Unidade de Oftalmologia de Coimbra (UOC), Coimbra, Portugal.

Methods

This retrospective case series included a total of 74 eyes of 51 patients. The postoperative spherical equivalent for the same implanted IOL was estimated using the following formulas: Barrett True-K, Haigis-L, Shammas, PhacoOptics®, SRK/T Double K, Holladay 1 Double K, Emmetropia Verifying Optical (EVO) v2.0, Masket, Modified Masket, Intraoperative Wavefront Aberrometry (IWA), and the average American Society of Cataract and Refractive Surgery (ASCRS) calculator. Outcomes included the mean absolute prediction error (MeanAE) and proportion of eyes within 0.25, 0.50, 0.75, and 1.00 diopters (D) of this prediction. 

Results

In eyes that had undergone prior myopic laser treatment with no historical data (n=54), the EVO No History yielded the lowest MeanAE (0.40 D). This was followed by the average ASCRS (0.40 D), Barrett True-K No History (0.41 D) and Shammas (0.45 D). In post-myopic eyes with available historical data (n=35), Barrett True-K yielded the lowest MeanAE (0.49 D). This was followed by average ASCRS (0.49 D), EVO (0.50 D) and IWA (0.52 D). In the hyperopic group (n=20), the PhacoOptics® No History exhibited the best performance (0.27 D), followed by the Shammas (0.29 D) and IWA (0.30 D).

Conclusions

This study demonstrated that even without historical data, IOL power calculation formulas yield high accuracy in patients with a history of refractive surgery. The EVO No History formula exhibited the greatest performance in post-myopic eyes, and the PhacoOptics® No History in post-hyperopic eyes.