Development of a program for toric intraocular lens calculation considering posterior corneal astigmatism, incision-induced posterior corneal astigmatism, and effective lens position

Eom, Youngsub; Ryu, Dongok; Kim, Dae Wook; Yang, Seul Ki; Song, Jong Suk; Kim, Sug Whan; Kim, Hyo Myung

doi:10.1007/s00417-016-3446-3

Cited by 18 publications

(10 citation statements)

References 36 publications

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“…The treatment must be adjusted according to the nomogram for high astigmatism correction via FS-LASIK, and overcorrection may be related to fewer adjustments for corrections. The effective lens position and posterior corneal astigmatism might represent influencing factors in Toric ICL when the Toric intraocular lens is used to correct for astigmatism in cataract surgery [ 21 ].…”

Section: Discussionmentioning

confidence: 99%

Vector Analysis of the Effects of FS-LASIK and Toric ICL for Moderate to High Astigmatism Correction

Chen

Zhou

et al. 2018

Journal of Ophthalmology

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Purpose To estimate the treatment effectiveness of femtosecond-assisted laser in situ keratomileusis (FS-LASIK) and Toric implantable collamer lens (Toric ICL) for moderate and high astigmatism via vector analysis. Materials and Methods The study involved 44 eyes from 44 patients who had a preoperative refractive cylinder ≥1.0 diopters (D) and underwent bilateral FS-LASIK or Toric ICL surgery. The examinations included corrected distance visual acuity measurement and subjective refraction before and 3 months after surgery. The astigmatic changes were estimated using vector analysis. Results No statistically significant differences were found in cylindrical refraction and percentage of spherical equivalent within 0 D, ±0.50 D, ±1.00 D, and ±1.50 D between the FS-LASIK and Toric ICL groups at 3 months after surgery. The parameters of the vector analysis included intended refractive correction, surgically induced refractive correction, error vector, correction ratio, error ratio, error of magnitude, and error of angle, with no significant differences between the groups. However, error ratio the of the off-axis correction in the FS-LASIK and Toric ICL groups was 4.11 ± 3.02 and 8.11 ± 3.82, respectively, and the difference was significant (t = −2.46, p=0.02). Conclusion Both FS-LASIK and Toric ICL were effective for correcting moderate and high astigmatism, although Toric ICL might produce a larger error of angle than FS-LASIK when an off-axis correction occurs.

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Section: Discussionmentioning

confidence: 99%

Vector Analysis of the Effects of FS-LASIK and Toric ICL for Moderate to High Astigmatism Correction

Chen

Zhou

et al. 2018

Journal of Ophthalmology

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“…Excel (Microsoft, Inc.) was used to develop a K-adjusted IOL power calculator (Supplementary Material; and an online calculator, available in the public domain at http://www.eo my.kr/kadjiolcalc). 9,11,14 This calculator enables easy calculation of the predicted refraction and IOL power using the Haigis, Hoffer Q, and SRK/T formulae with adjusted corneal power based on the posterior/anterior corneal curvature radii ratio ( Fig. 1).…”

Section: Iol Power Calculator Using Adjusted Corneal Powermentioning

confidence: 99%

Use of the Posterior/Anterior Corneal Curvature Radii Ratio to Improve the Accuracy of Intraocular Lens Power Calculation: Eom's Adjustment Method

Kim

Eom

Lee

et al. 2018

Invest. Ophthalmol. Vis. Sci.

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“…1 Different methodologies have been developed and validated to take this contribution of posterior corneal astigmatism into account for the calculation of toric IOL power, providing different levels of optimization of clinical outcomes. 1–8 A coefficient of adjustment of 0.75 for with-the-rule (WTR) anterior corneal astigmatisms, and a coefficient of 1.41 for against-the-rule (ATR) astigmatisms was suggested by Goggin et al 8 in toric IOL power calculations for cases requiring power values of 2 D of cylinder or less, according to calculations with unadjusted measurements. Eom et al 5 developed a new program for toric IOL power calculation, considering posterior corneal astigmatism, incision-induced posterior corneal astigmatism, and effective lens position.…”

Section: Introductionmentioning

confidence: 99%

Microincision cataract surgery with implantation of a bitoric intraocular lens using an enhanced program for intraocular lens power calculation

Lesieur¹

2019

European Journal of Ophthalmology

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Purpose: To evaluate the potential benefit of a new version of an online toric intraocular lens calculator in eyes implanted with a bitoric intraocular lens. Patients and methods: Retrospective observational comparative study in patients that underwent cataract surgery with implantation of the bitoric intraocular lens AT TORBI 709M (Carl Zeiss Meditec AG, Jena, Germany). Visual and refractive outcomes were evaluated at 1 month after surgery. The selection of the toric intraocular lens power was performed with the software Z CALC 2.0 (Carl Zeiss Meditec AG). The absolute refractive prediction errors for the spherical equivalent and cylinder were calculated and compared with the values that would have been obtained using version 1.5 of the same software. Results: A total of 393 eyes of 276 patients were evaluated. Mean postoperative sphere and cylinder were +0.03 ± 0.54 and −0.19 ± 0.30 D, respectively. A total of 95.67%, 98.22%, and 95.17% of eyes had a postoperative sphere, cylinder, and spherical equivalent within ±1.00 D, respectively. Mean absolute refractive prediction error for spherical equivalent was 0.34 ± 0.27 D with the two versions of the Z CALC software. In contrast, a significantly higher absolute refractive prediction error value for the cylinder was found with Z CALC 1.5 compared to version 2.0 (0.35 ± 0.32 vs 0.28 ± 0.30 D, p < 0.001). The absolute refractive prediction error for cylinder was ⩽0.25 D in 62.3% and 47.5% when using the versions 2.0 and 1.5, respectively. Conclusion: The use of an optimized software for toric intraocular lens power calculation, considering the contribution of posterior corneal astigmatism, improved the astigmatic outcome with a bitoric intraocular lens.

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Development of a program for toric intraocular lens calculation considering posterior corneal astigmatism, incision-induced posterior corneal astigmatism, and effective lens position

Abstract: Background

Cited by 18 publications

References 36 publications

Vector Analysis of the Effects of FS-LASIK and Toric ICL for Moderate to High Astigmatism Correction

Vector Analysis of the Effects of FS-LASIK and Toric ICL for Moderate to High Astigmatism Correction

Use of the Posterior/Anterior Corneal Curvature Radii Ratio to Improve the Accuracy of Intraocular Lens Power Calculation: Eom's Adjustment Method

Microincision cataract surgery with implantation of a bitoric intraocular lens using an enhanced program for intraocular lens power calculation

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