Effect of Segmented Optical Axial Length on the Performance of New-Generation Intraocular Lens Power Calculation Formulas in Extremely Long Eyes

So Goto; Naoyuki Maeda; Kota Uehara; Keiko Ogawa; Maki Matsumaru; Saori Sugiyama; Kazuhiko Ohnuma; Tjundewo Lawu; Toru Noda

doi:10.3390/jcm12226959

Effect of Segmented Optical Axial Length on the Performance of New-Generation Intraocular Lens Power Calculation Formulas in Extremely Long Eyes

J Clin Med. 2023 Nov 7;12(22):6959. doi: 10.3390/jcm12226959.

Authors

So Goto^{1

2

3}, Naoyuki Maeda¹, Kota Uehara², Keiko Ogawa², Maki Matsumaru², Saori Sugiyama², Kazuhiko Ohnuma⁴, Tjundewo Lawu⁵, Toru Noda²

Affiliations

¹ Department of Ophthalmology, Osaka University Graduate School of Medicine, Yamadaoka 2-2, Suita 565-0871, Osaka, Japan.
² Department of Ophthalmology, National Hospital Organization, Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo 152-8902, Japan.
³ Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA 94720, USA.
⁴ Laboratorio de Lente Verde, 98-1 Nozomino, Sodegaura 299-0251, Chiba, Japan.
⁵ VO, 3-10-20 Honcho, Toda 335-0023, Saitama, Japan.

Abstract

Purpose: To evaluate the performance of traditional vergence formulas with segmented axial length (AL) compared to traditional composite AL in extremely long eyes, and to determine whether the segmented AL can be extended to the new-generation formulas, including the Barrett Universal II, Emmetropia Verifying Optical 2.0 (EVO2), Hill-RBF 3.0 (Hill3), Kane, and Ladas Super formula (LSF) formulas in extremely long eyes.

Setting: National Hospital. Organization, Tokyo Medical Center, Japan.

Design: Retrospective case series.

Methods: Consecutive patients who underwent uncomplicated cataract surgery implanted with a three-piece intraocular lens between December 2015 and March 2021 were retrospectively reviewed. The composite AL was measured with a swept-source optical coherence tomography (SS-OCT) biometer using a mean refractive index. The segmented AL was calculated by summing the geometric lengths of the ocular segments (cornea, aqueous, lens, and vitreous) using multiple specific refractive indices based on the data obtained by the SS-OCT-based biometer. When refraction was measured at three months postoperatively, the median absolute errors (MedAEs) were calculated with two ALs for each formula.

Results: The study included 31 eyes of 22 patients. The segmented AL (30.45 ± 1.23 mm) was significantly shorter than the composite AL (30.71 ± 1.28 mm, p < 0.001). The MedAEs were significantly reduced when using segmented AL for SRK/T, Haigis, Hill3, and LSF, compared to those obtained using composite AL (0.38 vs. 0.62, 0.48 vs. 0.79, 0.50 vs. 0.90, 0.34 vs. 0.61, p < 0.001 for all formulas, respectively). On the contrary, the MedAE obtained by Kane with segmented AL was significantly worse compared to the one with composite AL (0.35 vs. 0.27, p = 0.03).

Conclusion: In extremely high myopic eyes, the segmented AL improves the performance of SRK/T, Haigis, Hill3, and LSF formulas compared to the composite AL, while the segmented AL worsens the prediction accuracy of the Kane formula.

Keywords: extremely long eye; new-generation IOL power calculation formulas; segmented axial length; swept-source optical coherence tomography-based biometer.

Grants and funding

So Goto is supported by a Japan Eye Bank Association Research Grant. Financial disclosures: No conflicting relationships exist for any other author. This paper will be presented in the poster session at the American Academy of Ophthalmology Annual Meeting, San Francisco, CA, USA, in November 2023.