Accuracy of intraocular lens power formulas in eyes with keratoconus: Multi-center study in Japan

Tomohiro Yokogawa; Yosai Mori; Hidemasa Torii; So Goto; Yumi Hasegawa; Takashi Kojima; Kazutaka Kamiya; Takuya Shiba; Kazunori Miyata

doi:10.1007/s00417-024-06371-7

Accuracy of intraocular lens power formulas in eyes with keratoconus: Multi-center study in Japan

Graefes Arch Clin Exp Ophthalmol. 2024 Jan 13. doi: 10.1007/s00417-024-06371-7. Online ahead of print.

Authors

Tomohiro Yokogawa¹, Yosai Mori², Hidemasa Torii³, So Goto^{4

5

6}, Yumi Hasegawa⁷, Takashi Kojima⁸, Kazutaka Kamiya⁹, Takuya Shiba¹⁰, Kazunori Miyata²

Affiliations

¹ Miyata Eye Hospital, Kurahara 6-3, Miyakonojo, Miyazaki, 885-0051, Japan. yokogawa@miyata-med.ne.jp.
² Miyata Eye Hospital, Kurahara 6-3, Miyakonojo, Miyazaki, 885-0051, Japan.
³ Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-Ku, Tokyo, 160-8582, Japan.
⁴ Department of Ophthalmology, Osaka University Graduate School of Medicine, Room E7, Yamadaoka 2-2, Suita, Osaka, 565-0871, Japan.
⁵ Department of Ophthalmology, Tokyo Medical Center, National Hospital Organization, 2-5-1 Higashigaoka, Meguro-Ku, Tokyo, 152-8902, Japan.
⁶ Herbert Wertheim School Optometry and Vision Science, University of California, Berkeley, CA, 94720-2020, USA.
⁷ Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, 2-1-1 Amakubo, Tsukuba, Ibaraki, 305-8076, Japan.
⁸ Nagoya Eye Clinic, 24-14 Namiyose, Atsuta-Ku, Nagoya, Aichi, 456-0003, Japan.
⁹ Department of Ophthalmology, Kitasato University, 1-15-1 Kitasato, Minami-Ku, Sagamihara, Kanagawa, 252-0373, Japan.
¹⁰ Roppongi Shiba Eye Clinic, Minato-Ku, Tokyo, Japan.

PMID: 38217766
DOI: 10.1007/s00417-024-06371-7

Abstract

Purpose: To assess the accuracy of intraocular lens (IOL) power formulas, namely, SRK/T, Haigis, Barrett Universal II, Barrett True-K for keratoconus, Kane formula, and Kane formula for keratoconus, for cataract with keratoconus in Japanese eyes.

Setting: Five surgical sites in Japan.

Design: A retrospective case series.

Methods: Eyes with keratoconus undergoing cataract surgery were included. Postoperative refraction was compared with the prediction by the formulas. Visual acuity, manifest spherical equivalent, prediction error (PE), and mean absolute errors (MAEs) were determined 1 month postoperatively. The PE within 0.50 diopter (D), 1.00 D, and 2.00 D were compared between IOL formulas. Subgroup analysis based on the steepest keratometry (stage 1, ≤ 48 D; stage 2, > 48 D and ≤ 53 D; and stage 3, > 53 D) was performed. The relationship between PE and preoperative biometric data were assessed.

Results: Fifty eyes were included. The MAE of the Barrett True-K for keratoconus, Kane keratoconus, and Kane formulas were significantly lower than that of Haigis. A statistically significant difference in the prediction accuracy within ± 0.50 D was found between Kane keratoconus and Haigis. The prediction accuracy of the Barrett True-K for keratoconus, SRK/T, and Kane within ± 1.00 D was statistically significant compared with that of Haigis. In stage 3, the Barrett True-K for keratoconus had a significantly lower MAE than SRK/T and Haigis.

Conclusion: Keratoconus-specific formulas were more accurate than existing formulas in Japanese eyes. The Barrett True-K formula for keratoconus had higher prediction accuracy in severe keratoconus.

Keywords: Barrett True-K formula for keratoconus; Japanese eye; Kane keratoconus formula; Keratoconus.