Intraocular lens power calculation for eyes with high and low average keratometry readings: Comparison between various formulas

Reitblat, Olga; Levy, Adi; Kleinmann, Guy; Lerman, Tsahi T.; Assia, Ehud I.

doi:10.1016/j.jcrs.2017.06.036

Cited by 61 publications

(36 citation statements)

References 15 publications

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“…In eyes with normal ALs and high AL/CR ratios, the SRK/ T formula had a strong tendency toward myopic results. Reitblat and colleagues 53 reported that the IOL power calculations for eyes with steep corneas yielded myopic prediction errors with the SRK/T formula. Melles and colleagues 54 reported that the SRK/T formula tended to overestimate the IOL power in eyes with steep corneas.…”

Section: Accuracy Of Iol Power Calculations Accordingmentioning

confidence: 99%

Ratio of Axial Length to Corneal Radius in Japanese Patients and Accuracy of Intraocular Lens Power Calculation Based on Biometric Data

Omoto

Torii

Hayashi

et al. 2020

American Journal of Ophthalmology

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MIKI KAMIKAWATOKO OMOTO, HIDEMASA TORII, KEN HAYASHI, MASAHIKO AYAKI, KAZUO TSUBOTA, AND KAZUNO NEGISHI PURPOSE: To evaluate the features of the axial lengthto-corneal radius (AL/CR) ratio in Japanese patients with cataracts and to determine the accuracy of intraocular lens (IOL) power calculation formulas according to the AL/CR features and the axial length (AL).DESIGN: Retrospective observational case series. METHODS: Setting was a clinical practice. Patient population was a total of 1,135 eyes (1,135 patients) with cataracts. Observation procedures included measurement of the AL and corenal radius (CR) by optical biometry and evaluation of the refractive outcomes by using the SRK/T, Holladay 1, Hoffer Q, Haigis, and Barrett Universal II formulas. Main outcome measurements were the features of the AL/CR ratio and the accuracy of IOL power calculations based on the AL/CR ratio and the AL.RESULTS: The mean AL/CR ratio was 3.15 ± 0.19. Significant weak negative correlations were observed between the spherical equivalent (SE) and AL (r [ L0.7489; P < .001) and between the SE and AL/CR ratio (r [ L0.8069; P < .001); no correlation was found between the SE and CR (r [ 0.0208, P [ .483). For medium ALs and high AL/CR ratios, the SRK/T formula performed less accurately. For long ALs and high AL/CR ratios, the Holladay 1 and Hoffer Q formulas performed less accurately. The Barrett Universal II formula performed well across a range of ALs and AL/CR ratios. CONCLUSIONS: The AL/CR ratio explained the total variation in the SE better than the AL alone. Surgeons should pay attention to the selection of IOL power calculation formulas in eyes with high AL/CR ratios. (Am J Ophthalmol 2020;-:---. Ó

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Section: Accuracy Of Iol Power Calculations Accordingmentioning

confidence: 99%

Ratio of Axial Length to Corneal Radius in Japanese Patients and Accuracy of Intraocular Lens Power Calculation Based on Biometric Data

Omoto

Torii

Hayashi

et al. 2020

American Journal of Ophthalmology

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“…Faramarzi et al [9] demonstrated that the prediction error was −0.06 ± 0.52 D in eyes with a keratometry >46 D using the SRK/T formula, but that the sample size was limited (n � 45). Reitblat et al [10] showed that myopic refractive errors (−0.31 ± 0.54 D) were found in eyes with a keratometry >46 D, but hyperopic errors (0.16 ± 0.31 D) were noted in eyes with a keratometry <42 D, when the SRK/T formula was used, and that the prediction error was −0.04 ± 0.45 D and −0.07 ± 0.26 D, in eyes with a keratometry >46 D and <42 D, respectively, both of which were not significantly different from zero, when the Barrett Universal II formula was used. eir previous findings are in accordance with our current findings in terms of the prediction error.…”

Section: Discussionmentioning

confidence: 99%

“…However, to date, there have only been a few studies on the predictability of the IOL power calculation using the two major formulas, according to the keratometric readings [8][9][10]. Moreover, the detailed relationship between the predictability outcomes and the keratometry has so far not been elucidated using the two major formulas.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Predictability Using Barrett Universal II and SRK/T Formulas according to Keratometry

Iijima

Kamiya

Iida

et al. 2020

Journal of Ophthalmology

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Purpose. To compare the predictability of intraocular lens (IOL) power calculation using the Barrett Universal II and the SRK/T formulas, according to the keratometry. Methods. We retrospectively reviewed the clinical charts of 335 consecutive eyes undergoing standard cataract surgery. IOL power calculations were performed using the Barrett Universal II and the SRK/T formulas. We compared the prediction error, the absolute error, and the percentages within ±0.25, ±0.5, and ±1.0 D of the targeted refraction, 1 month postoperatively, and also investigated the relationship of these outcomes with the keratometric readings, using the two formulas. Results. The prediction error using the SRK/T formula was significantly more myopic than that using the Barrett Universal II formula (the paired t-test, p<0.001). The absolute error using the SRK/T formula was significantly larger than that using the Barrett Universal II formula (p=0.006). We found a significant correlation between the prediction error and the keratometric readings using the SRK/T formula (Pearson correlation coefficient, r = −0.522, p<0.001), but there was no significant correlation between them using the Barrett Universal II formula (r = −0.031, p=0.576). Conclusions. The Barrett Universal II formula provides a better predictability of IOL power calculation and is less susceptible to the effect of the corneal shape, than the SRK/T formula. The Barrett Universal formula, instead of the SRK/T formula, may be clinically helpful for improving the refractive accuracy, especially in eyes with steep or flat corneas.

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“…The Haigis formula incorporates the AL into the calculation; however, it is noted in clinical practice that small errors in postoperative refractive spherical equivalent still exist. 14 , 15 …”

Section: Introductionmentioning

confidence: 99%

Clinical outcomes following trifocal diffractive intraocular lens implantation for age-related cataract in China

Yang¹,

Lv²,

Wang³

et al. 2018

OPTH

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PurposeThe aim of this study was to evaluate visual, refractive and patient satisfaction outcomes following implantation of a trifocal diffractive intraocular lens (IOL).Patients and methodsThis prospective, consecutive study included patients undergoing lens phacoemulsification of cataract and implantation of a trifocal diffractive IOL (AT LISA tri 839MP). Visual outcomes, including near, intermediate and distance visual acuity (VA), refractive error, contrast sensitivity, defocus curve and patient satisfaction were assessed preoperatively and postoperatively.ResultsThirty IOLs were implanted in 26 patients. Distance VA improved significantly from 0.70±0.45 to 0.08±0.11 logMAR (p<0.0001) 1 week postoperatively, and to 0.07±0.13 logMAR (p<0.0001) at 1 month and 0.05±0.10 logMAR (p<0.0001) at 3 months. Uncorrected near and intermediate VA, as well as corrected near, intermediate and distance VA, were stable and maintained during the follow-up period. Preoperative anterior chamber depth demonstrated an association with effective adjustment of postoperative spherical equivalent using a regression formula (p=0.007). No significant differences were observed for VA at defocus curves of 0 to −3 D. Contrast sensitivity at each spatial frequency improved significantly at 1 week, 1 month and 3 months under photopic and photopic with glare conditions. Under mesopic and mesopic with glare conditions, significant differences were observed postoperatively at low and medium spatial frequencies. Patients reported a high level of satisfaction and an absence of glare or halo 3 months postoperatively.ConclusionIn this study, the trifocal diffractive IOL provided excellent visual performance at all distances and improved contrast sensitivity under different conditions, resulting in high levels of patient satisfaction and spectacle independence in Chinese patients.

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Intraocular lens power calculation for eyes with high and low average keratometry readings: Comparison between various formulas

Abstract: Power calculation for eyes with flat corneas and steep corneas requires the use of specific formulas for accurate postoperative results. An adjustment method of the SRK/T formula is proposed.

Cited by 61 publications

References 15 publications

Ratio of Axial Length to Corneal Radius in Japanese Patients and Accuracy of Intraocular Lens Power Calculation Based on Biometric Data

Ratio of Axial Length to Corneal Radius in Japanese Patients and Accuracy of Intraocular Lens Power Calculation Based on Biometric Data

Comparison of Predictability Using Barrett Universal II and SRK/T Formulas according to Keratometry

Clinical outcomes following trifocal diffractive intraocular lens implantation for age-related cataract in China

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