Keratometric influence in ten IOL calculation formulas for long eyes

Abstract

Purpose : To compare and determine the best intraocular lens formula in eyes greater than 25mm with normal and keratometries greater than 45D.

Methods : Retrospective comparative study. 119 eyes with axial length 25mm were included and divided into two groups: Ksteep (45D) and Kreg (<45D). Refractive error (RE) was calculated with 10 calculation formulas. Mean absolute error (MAE) and median absolute error (MedAE) of RE were compared. The percentage of eyes was obtained at ±0.50, ±1.00 and ±2.00 diopters, as well as the OR of achieving a refraction at ±0.50D.

Results : For the Ksteep group, the lowest MAE was from Panacea, Kane and Barret U2. The lowest MedAE was Ladas, Panacea and SRKII with the highest percentage in ±0.50D of Panacea and Kane. For the Kreg group the lowest MAE was from Kane and Hill-BRF. The lowest percentage at ±0.50D of Kane, Barret U2 and Haigis. All the formulas except Hill-BRF and Barret U2 presented statistically significant difference in MedAE between both groups.

Conclusions : Kane and Panacea had the best results for long eyes with keratometries greater than 45D. For long eyes with normal keratometries the best formulas were Hill-BRF and Barret U2. The latter can be used in long eyes regardless of keratometry.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.