Accuracy of intraocular lens power calculation for cataract surgery after deep anterior lamellar keratoplasty

Abstract

Background: The purpose of this study was to assess the accuracy of intraocular lens power (IOL) formulas for cataract surgery after deep anterior lamellar keratoplasty (DALK). Methods: This retrospective study included eyes which had previously undergone DALK and underwent standard phacoemulsification with monofocal IOL implantation between January 2012 and January 2021 at Ospedali Privati Forlì "Villa Igea" (Forlì, Italy). The predicted spherical equivalent (SE) was calculated using the Barrett Universal II, Emmetropia Verifying Optical (EVO), Haigis, Hoffer Q, Hoffer QST, Holladay 1, Holladay II, Kane and SRK/T formulas. Prediction error (PE) was calculated as the actual postoperative SE refraction minus the SE predicted refraction. Results: Eighty-two eyes of 82 patients were included. The mean PE was negative using all formulas. Friedman test revealed a statistically significant difference of the median absolute PE (MedAE) among the different IOL formulas (P = 0.005). On the basis of the MedAE, the formulas were ranked as follows: SRK/T (0.805 D), Kane (0.810 D), EVO (0.845 D), Hoffer QST (0.847 D), Barrett (0.895 D), Holladay 1 (0.915 D), Haigis (1.010 D) and Hoffer Q (1.070 D) formulas. Conclusions: All formulas had a tendency towards a myopic refractive shift in post-DALK eyes. Although the SRK/T, Kane, EVO and Hoffer QST formulas were more accurate, predictability of refractive outcomes was lower than in virgin eyes.

A Review of Intraocular Lens Power Calculation Formulas Based on Artificial Intelligence

“…It requires further examination. Initial results showed that Hoffer QST failed to yield more accurate predictions than other formulas (Shammas et al, 2022) [26], however, it outperformed the others in eyes which had undergone deep anterior lamellar keratoplasty [49].…”

Large-diameter deep anterior lamellar keratoplasty: A narrative review

“…[ 53 ] In the presence of a cataract, lens extraction with implantation of monofocal or even toric intraocular lenses can also be contemplated. [ 54 55 ]…”

Management of post-keratoplasty ametropia

“…Despite the lower accuracy of formulas in post-DALK eyes than eyes without prior surgery, SRK/T, Kane, Emmetropia Verifying Optical, Hoffer QST were more reliable than other formulas. 106 Phakic IOL Compared to laser refractive surgery, phakic IOLs provide a broader range of refractive error correction, and apart from faster visual rehabilitation, maintaining accommodation, stable refraction, and reversibility, they are not limited by corneal thickness or topography. 107 In addition, Feizi et al reported that phakic IOLs yield superior visual outcomes compared to LASIK in a retrospective study involving 33 post-PK eyes.…”

“…Despite the lower accuracy of formulas in post-DALK eyes than eyes without prior surgery, SRK/T, Kane, Emmetropia Verifying Optical, Hoffer QST were more reliable than other formulas. 106 …”