scholarly journals Intraocular lens power calculations in eyes with pseudoexfoliation syndrome

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aleksandra Wlaź ◽  
Agnieszka Kustra ◽  
Agnieszka Rozegnał-Madej ◽  
Tomasz Żarnowski
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Prediction Error ◽  
Absolute Error ◽  
Pseudoexfoliation Syndrome ◽  
Control Group ◽  
Refractive Outcomes ◽  
Iol Calculation ◽  
Lens Power ◽  
And Control

AbstractTo compare refractive outcomes after cataract surgery in pseudoexfoliation syndrome (PEX) and control eyes and to investigate the accuracy of 3 intraocular lens (IOL) calculation formulas in these eyes. In this prospective comparative study 42 eyes (PEX group) and 38 eyes (control group) of 80 patients were included. The follow-up was 3 months. The refractive prediction error (RPE), mean absolute error (MAE), median absolute error (MedAE) and the percentages of eyes within ± 0.25 D, ± 0.5 D, ± 1.0 D and ± 2.0 D of prediction error were calculated. Three IOL calculation formulas (SRK/T, Barrett Universal II and Hill-RBF) were evaluated. PEX produced statistically significantly higher mean absolute errors and lower percentages of eyes within ± 0.5 D than control eyes in all investigated IOL calculation formulas. There were no statistically significant differences in the median absolute errors between the 3 formulas in either PEX or control eyes. Refractive outcomes after cataract surgery are statistically significantly worse in PEX than in control eyes. All three IOL calculation formulas produced similar results in both PEX and control eyes.Trial registration: ClinicalTrials.gov registration number NCT04783909.

scholarly journals Comparing prediction accuracy between total keratometry and conventional keratometry in cataract surgery with refractive multifocal intraocular lens implantation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ho Seok Chung ◽  
Jae Lim Chung ◽  
Young Jun Kim ◽  
Hun Lee ◽  
Jae Yong Kim ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Prediction Error ◽  
Prediction Accuracy ◽  
Absolute Error ◽  
Multifocal Intraocular Lens ◽  
Swept Source ◽  
Iol Implantation ◽  
Multifocal Iol ◽  
Refractive Outcomes

AbstractWe aimed to compare refractive outcomes between total keratometry using a swept-source optical biometer and conventional keratometry in cataract surgery with refractive multifocal intraocular lens (IOL) implantation. We included patients who underwent cataract surgery with refractive multifocal IOL implantation. The IOL power was calculated using conventional formulas (Haigis, SRK/T, Holladay 2, and Barrett Universal II) as well as a new formula (Barrett TK Universal II). The refractive mean error, mean absolute error, and median absolute error were compared, as were the proportions of eyes within ± 0.25 diopters (D), ± 0.50 D, and ± 1.00 D of prediction error. In total 543 eyes of 543 patients, the absolute prediction error of total keratometry was significantly higher than that of conventional keratometry using the SRK/T (P = 0.034) and Barrett Universal II (P = 0.003). The proportion of eyes within ± 0.50 D of the prediction error using the SRK/T and Barrett Universal II was also significantly higher when using conventional keratometry than total keratometry (P = 0.010 for SRK/T and P = 0.005 for Barrett Universal II). Prediction accuracy of conventional keratometry was higher than that of total keratometry in cataract surgery with refractive multifocal IOL implantation.

scholarly journals Comparison of Two Toric IOL Calculation Methods

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
C. Kern ◽  
K. Kortüm ◽  
M. Müller ◽  
A. Kampik ◽  
S. Priglinger ◽  
...  
Keyword(s):  
Intraocular Lens ◽  
Absolute Error ◽  
Spherical Equivalent ◽  
Calculation Methods ◽  
Refractive Outcome ◽  
Toric Intraocular Lens ◽  
Iol Calculation ◽  
Median Absolute Error ◽  
Lens Power ◽  
Posterior Corneal Astigmatism

Purpose. To compare two calculators for toric intraocular lens (IOL) calculation and to evaluate the prediction of refractive outcome. Methods. Sixty-four eyes of forty-five patients underwent cataract surgery followed by implantation of a toric intraocular lens (Zeiss Torbi 709 M) calculated by a standard industry calculator using front keratometry values. Prediction error, median absolute error, and refractive astigmatism error were evaluated for the standard calculator. The predicted postoperative refraction and toric lens power values were evaluated and compared after postoperative recalculation using the Barrett calculator. Results. We observed a significant undercorrection in the spherical equivalent (0.19 D) by using a standard calculator (p≤0.05). According to the Baylor nomogram and the refractive influence of posterior corneal astigmatism (PCA), undercorrection of the cylinder was lower for patients with WTR astigmatism, because of the tendency of overcorrection. An advantage of less residual postoperative SE, sphere, and cylinder for the Barrett calculator was observed when retrospectively comparing the calculated predicted postoperative refraction between calculators (p≤0.01). Conclusion. Consideration of only corneal front keratometric values for toric lens calculation may lead to postoperative undercorrection of astigmatism. The prediction of postoperative refractive outcome can be improved by using appropriate methods of adjustment in order to take PCA into account.

scholarly journals Inter-ocular and inter-visit differences in ocular biometry and refractive outcomes after cataract surgery

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hyun Sup Choi ◽  
Hyo Soon Yoo ◽  
Yerim An ◽  
Sam Young Yoon ◽  
Sung Pyo Park ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Axial Length ◽  
The Other ◽  
Corneal Power ◽  
Refractive Outcomes ◽  
Ocular Biometry ◽  
Intraocular Lens Power ◽  
Lens Power ◽  
Group D

Abstract This study aimed to determine whether inter-ocular differences in axial length (AL), corneal power (K), and adjusted emmetropic intraocular lens power (EIOLP) and inter-visit differences in these ocular biometric values, measured on different days, are related to refractive outcomes after cataract surgery. We retrospectively reviewed 279 patients who underwent phacoemulsification. Patients underwent ocular biometry twice (1–4 weeks before and on the day of surgery). Patients were divided into three groups: group S (similar inter-ocular biometry in different measurements; n = 201), group P (inter-ocular differences persisted in the second measurement; n = 37), and group D (inter-ocular difference diminished in the second measurement; n = 41). Postoperative refractive outcomes (mean absolute errors [MAEs]) were compared among the groups. Postoperative MAE2, based on second measurement with reduced inter-ocular biometry difference, was smaller than that calculated using the first measurement (MAE1) with borderline significance in group D (MAE1, 0.49 ± 0.45 diopters vs. MAE2, 0.41 ± 0.33 diopters, p = 0.062). Postoperative MAE2 was greater in group P compared to the other two groups (p = 0.034). Large inter-ocular biometry differences were associated with poor refractive outcomes after cataract surgery. These results indicate that measurements with smaller inter-ocular differences were associated with better refractive outcomes in cases with inter-visit biometry differences.

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

2019 ◽  
Vol 30 (6) ◽  
pp. 1308-1313
Author(s):  
Gilles Lesieur
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Prediction Error ◽  
Power Calculation ◽  
Spherical Equivalent ◽  
Toric Intraocular Lens ◽  
Intraocular Lens Power Calculation ◽  
Intraocular Lens Power ◽  
Lens Power ◽  
Lens Power Calculation

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.

scholarly journals Lenstar LS 900 versus Pentacam-AXL: analysis of refractive outcomes and predicted refraction

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Henrique Aragão Arruda ◽  
Joana M. Pereira ◽  
Arminda Neves ◽  
Maria João Vieira ◽  
Joana Martins ◽  
...  
Keyword(s):  
Refractive Error ◽  
Prediction Error ◽  
Mean Absolute Error ◽  
Absolute Error ◽  
Spherical Equivalent ◽  
Refractive Outcomes ◽  
Iol Calculation ◽  
Median Absolute Error ◽  
The Difference ◽  
Mean Prediction Error

AbstractAnalysis of refractive outcomes, using biometry data collected with a new biometer (Pentacam-AXL, OCULUS, Germany) and a reference biometer (Lenstar LS 900, HAAG-STREIT AG, Switzerland), in order to assess differences in the predicted and actual refraction using different formulas. Prospective, institutional study, in which intraocular lens (IOL) calculation was performed using the Haigis, SRK/T and Hoffer Q formulas with the two systems in patients undergoing cataract surgery between November 2016 and August 2017. Four to 6 weeks after surgery, the spherical equivalent (SE) was derived from objective refraction. Mean prediction error (PE), mean absolute error (MAE) and the median absolute error (MedAE) were calculated. The percentage of eyes within ± 0.25, ± 0.50, ± 1.00, and ± 2.00 D of MAE was determined. 104 eyes from 76 patients, 35 males (46.1%), underwent uneventful phacoemulsification with IOL implantation. Mean SE after surgery was − 0.29 ± 0.46 D. Mean prediction error (PE) using the SRK/T, Haigis and Hoffer Q formulas with the Lenstar was significantly different (p > 0.0001) from PE calculated with the Pentacam in all three formulas. Percentage of eyes within ± 0.25 D MAE were larger with the Lenstar device, using all three formulas. The difference between the actual refractive error and the predicted refractive error is consistently lower when using Lenstar. The Pentacam-AXL user should be alert to the critical necessity of constant optimization in order to obtain optimal refractive results.

scholarly journals Correlation of Binocular Refractive Errors and Calculation of Intraocular Lens Power for the Second Eye

2020 ◽  
Author(s):  
Pengcheng Zhang ◽  
Yuhuan Yang ◽  
Hong Yan ◽  
Jie Zhang ◽  
Weijia Yan
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Refractive Error ◽  
Control Group ◽  
Refractive Errors ◽  
Age Related ◽  
Department Of Ophthalmology ◽  
Group A ◽  
Iol Power ◽  
Lens Power

Abstract Background: How to reduce the refractive error has always been a tricky problem. The aim of this study was to verify the correlation between binocular refractive errors (RE) after sequential cataract surgery and explore the individualized calculation method of intraocular lens (IOL) for the second eye.Methods: This is a prospective study. One hundred eighty-eight affected eyes of 94 age-related cataract patients with sequential cataract surgery from the Department of Ophthalmology, Tangdu Hospital, china, were recruited. Complete case data of 94 patients were included for correlation analysis of binocular RE. Thereafter, data of patients with RE values greater than 0.50 diopter (D) in the first eyes were extracted and divided randomly into two groups- Group A and B. As the adjustment group, in group A we modified the IOL power for the second eyes according to 50% of the RE of the first eye, and group B was the control group without modify. The mean absolute refractive error (MARE) values of the second eyes were evaluated one month after surgery.Results: The correlation coefficient of binocular RE after sequential cataract surgery was 0.760 (P < 0.001). After the IOL power of the second eyes were adjusted, the MARE of the second eyes was 0.57±0.41 D while MARE of the first eyes was 1.18±0.85 D, and the difference was statistically significant (P<0.001).Conclusions: Binocular REs were correlated positively after sequential cataract surgery. The RE of the second eye can be reduced by adjusting the IOL power based on 50% of the postoperative RE of the first eye.

The Accuracy of Different Generation Intraocular Lens Power Formulas in Eyes with Axial Length Lower than 22 millimeter

2019 ◽  
Author(s):  
Aydın Yildiz ◽  
Sedat Arikan
Keyword(s):  
Intraocular Lens ◽  
Axial Length ◽  
Statistical Significance ◽  
Absolute Error ◽  
Accurate Estimation ◽  
Intraocular Lens Power ◽  
Significant Difference ◽  
Iol Calculation ◽  
Iol Power ◽  
Lens Power

Abstract Background:To investigate the accurate formulas for eyes with axial length (AL) lower than 22 millimeters among usually used six intraocular lens (IOL) calculation formulas. MethodsA total of 122 eyes with short ALs that is lower than 22 mm of 122 patients who underwent phacoemulsification surgery with the same type of IOL implantation were included in this retrospective study. The biometric values of the patients were obtained by using optical low coherence reflectometry (OLCR) for six formulas involving Hoffer Q, SRK-T, Haigis, Barett Universal II, Holladay 2 and Hill-RBF. All patients had a postoperative best corrected visual acuity level that is equal or higher than 20/40. While comparing the accuracy of these six IOL calculation formulas, the mean absolute error (MAE), and the median absolute error (MedAE) values were taken into account.ResultsThe MAE values for Hoffer Q, SRK-T, Haigis, Holladay 2, Hill-RBF and Barrett Universal II formulas were 0.390, 0.390, 0.324, 0.327, 0.331 and 0.208 respectively. Also the rank of MedAE values for the mentioned formulas was 0.245, 0.310, 0.310, 0.250, 0.255 and 0.190. The lowest MAE and MedAE value was found in Barrett Universal II formula, whereas the highest one was in the SRK/T formula with a statistical significance (p<0.001). After Bonferroni correction, there were no statistically significant difference between Barret Universal II formula and the other formulas except SRK/T (p>0.01). Three patients (2.5%) were in the ±0.75 D range, 15 patients (12.3%) were in the ±0.50 D, and the remaining 104 (85.2%) patients were in the ±0.25 D at the first month follow-up. ConclusionsAlthough Barrett Universal II appears to be the most accurate IOL calculation formula, third, fourth and other newer generation formulas have also a good predictive value for accurate estimation of IOL power in short eyes.

scholarly journals Correlation of Binocular Refractive Errors and Calculation of Intraocular Lens Power for the Second Eye

2020 ◽  
Author(s):  
Pengcheng Zhang ◽  
Yuhuan Yang ◽  
Hong Yan ◽  
Jie Zhang ◽  
Weijia Yan
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Refractive Error ◽  
Control Group ◽  
Refractive Errors ◽  
Age Related ◽  
Department Of Ophthalmology ◽  
Group A ◽  
Iol Power ◽  
Lens Power

Abstract Background How to reduce the refractive error has always been a tricky problem. The aim of this study was to verify the correlation between binocular refractive errors (RE) after sequential cataract surgery and explore the individualized calculation method of intraocular lens (IOL) for the second eye. Methods This is a prospective study. One hundred eighty-eight affected eyes of 94 age-related cataract patients with sequential cataract surgery from the Department of Ophthalmology, Tangdu Hospital, china, were recruited. Complete case data of 94 patients were included for correlation analysis of binocular RE. Thereafter, data of patients with RE values greater than 0.50 diopter (D) in the first eyes were extracted and divided randomly into two groups- Group A and B. As the adjustment group, in group A we modified the IOL power for the second eyes according to 50% of the RE of the first eye, and group B was the control group without modify. The mean absolute refractive error (MARE) values of the second eyes were evaluated one month after surgery. Results The correlation coefficient of binocular RE after sequential cataract surgery was 0.760 ( P < 0.001). After the IOL power of the second eyes were adjusted, the MARE of the second eyes was 0.57±0.41 D while MARE of the first eyes was 1.18±0.85 D, and the difference was statistically significant ( P <0.001). Conclusions Binocular REs were correlated positively after sequential cataract surgery. The RE of the second eye can be reduced by adjusting the IOL power based on 50% of the postoperative RE of the first eye.

Intraocular lens power calculation in virgin eyes: Accuracy of the Barrett Universal II formula and a Ray tracing software

2021 ◽  
pp. 112067212110655
Author(s):  
Joaquim Fernández-Rosés ◽  
José Lamarca ◽  
David P. Piñero ◽  
Rafael I. Barraquer
Keyword(s):  
Ray Tracing ◽  
Intraocular Lens ◽  
Prediction Error ◽  
Pupil Diameter ◽  
Absolute Error ◽  
Power Calculation ◽  
Intraocular Lens Power Calculation ◽  
Intraocular Lens Power ◽  
Lens Power ◽  
Lens Power Calculation

Purpose To compare the accuracy of Sirius ray tracing software with the Barrett Universal II formula for intraocular lens power prediction in virgin eyes. Methods Retrospective case series including 86 eyes that have undergone uneventful cataract surgery with SN60WF implantation. The median absolute error, mean prediction error, variance, and the percentage of eyes within ± 0.25 D, ± 0.50 D, ± 0.75 D, and ± 1.00 D of the prediction error in refraction were calculated. The correlation of prediction error with different baseline parameters was investigated. Results No differences were found between the median absolute error of the Barrett Universal II formula (0.226 D) and the ray tracing software with different intraocular lens centerings; apex (0.331 D), limbus (0.345 D), and pupil (0.342 D) ( p = 0.084). The variance, from lowest to highest, was the Barrett Universal II (0.144 D2), ray tracing-limbus (0.285 D2), ray tracing-pupil (0.285 D2), and ray tracing-apex (0.287 D2) ( p = 0.027). The Barrett Universal II formula showed a higher percentage of eyes within ± 0.25 D (56.98%), ± 0.50 D (82.56%), and ± 0.75 D (93.02%) compared to ray tracing software ( p < 0.01). A significant correlation between the prediction error of the Barrett Universal II formula and corneal diameter (r = 0.322, p = 0.002) and pupil diameter (r = 0.230, p = 0.033) was found. Also, a positive correlation between the prediction error of Sirius ray tracing and axial length ( p < 0.001) and pupil diameter ( p = 0.01) was found. Conclusion There is a trend of the Barrett Universal II formula to be more accurate than Sirius ray tracing software for intraocular lens power calculation in virgin eyes. This should be confirmed in future prospective comparative studies.

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