scholarly journals Gender differences in refraction prediction error of five formulas for cataract surgery

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yibing Zhang ◽  
Tingyang Li ◽  
Aparna Reddy ◽  
Nambi Nallasamy
Keyword(s):  
Gender Differences ◽  
Cataract Surgery ◽  
Prediction Error ◽  
Statistical Difference ◽  
Independent Predictor ◽  
Study Data ◽  
Prediction Errors ◽  
Optical Biometry ◽  
Iol Power ◽  
Lens Power

Abstract Objectives To evaluate gender differences in optical biometry measurements and lens power calculations. Methods Eight thousand four hundred thirty-one eyes of five thousand five hundred nineteen patients who underwent cataract surgery at University of Michigan’s Kellogg Eye Center were included in this retrospective study. Data including age, gender, optical biometry, postoperative refraction, implanted intraocular lens (IOL) power, and IOL formula refraction predictions were gathered and/or calculated utilizing the Sight Outcomes Research Collaborative (SOURCE) database and analyzed. Results There was a statistical difference between every optical biometry measure between genders. Despite lens constant optimization, mean signed prediction errors (SPEs) of modern IOL formulas differed significantly between genders, with predictions skewed more hyperopic for males and myopic for females for all 5 of the modern IOL formulas tested. Optimization of lens constants by gender significantly decreased prediction error for 2 of the 5 modern IOL formulas tested. Conclusions Gender was found to be an independent predictor of refraction prediction error for all 5 formulas studied. Optimization of lens constants by gender can decrease refraction prediction error for certain modern IOL formulas.

scholarly journals Gender Differences in Refraction Prediction Error of Five Formulas for Cataract Surgery

2021 ◽  
Author(s):  
Yibing Zhang ◽  
Tingyang Li ◽  
Aparna Reddy ◽  
Nambi Nallasamy
Keyword(s):  
Gender Differences ◽  
Cataract Surgery ◽  
Prediction Error ◽  
Statistical Difference ◽  
Independent Predictor ◽  
Study Data ◽  
Prediction Errors ◽  
Optical Biometry ◽  
Iol Power ◽  
Lens Power

Abstract Objectives: To evaluate gender differences in optical biometry measurements and lens power calculations. Methods: 8431 eyes of 5519 patients who underwent cataract surgery at University of Michigan’s Kellogg Eye Center were included in this retrospective study. Data including age, gender, optical biometry, postoperative refraction, implanted intraocular lens (IOL) power, and IOL formula refraction predictions were gathered and/or calculated utilizing the Sight Outcomes Research Collaborative (SOURCE) database and analyzed.Results: There was a statistical difference between every optical biometry measure between genders. Despite lens constant optimization, mean signed prediction errors (SPEs) of modern IOL formulas differed significantly between genders, with predictions skewed more hyperopic for males and myopic for females for all 5 of the modern IOL formulas tested. Optimization of lens constants by gender significantly decreased prediction error for 2 of the 5 modern IOL formulas tested.Conclusions: Gender was found to be an independent predictor of refraction prediction error for all 5 formulas studied. Optimization of lens constants by gender can decrease refraction prediction error for certain modern IOL formulas.

scholarly journals An innovative approach for determining the customized refractive index of ectatic corneas in cataractous patients

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shiva Pirhadi ◽  
Keivan Maghooli ◽  
Khosrow Jadidi
Keyword(s):  
Refractive Index ◽  
Cataract Surgery ◽  
Ray Tracing ◽  
Prediction Error ◽  
Power Calculation ◽  
Corneal Power ◽  
Iol Power Calculation ◽  
Iol Power ◽  
Hyperopic Shift ◽  
The Difference

Abstract The aim of this study is to determine the customized refractive index of ectatic corneas and also propose a method for determining the corneal and IOL power in these eyes. Seven eyes with moderate and severe corneal ectatic disorders, which had been under cataract surgery, were included. At least three months after cataract surgery, axial length, cornea, IOL thickness and the distance between IOL from cornea, and aberrometry were measured. All the measured points of the posterior and anterior parts of the cornea converted to points cloud and surface by using the MATLAB and Solidworks software. The implanted IOLs were designed by Zemax software. The ray tracing analysis was performed on the customized eye models, and the corneal refractive index was determined by minimizing the difference between the measured aberrations from the device and resulted aberrations from the simulation. Then, by the use of preoperative corneal images, corneal power was calculated by considering the anterior and posterior parts of the cornea and refractive index of 1.376 and the customized corneal refractive index in different regions and finally it was entered into the IOL power calculation formulas. The corneal power in the 4 mm region and the Barrett formula resulted the prediction error of six eyes within ± 1 diopter. It seems that using the total corneal power along with the Barrett formula can prevent postoperative hyperopic shift, especially in eyes with advanced ectatic disorders.

scholarly journals Postoperative Refractive Prediction Error Measured by Optical and Acoustic Biometry after Phacovitrectomy for Rhegmatogenous Retinal Detachment without Macular Involvement

2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Masashi Sakamoto ◽  
Izumi Yoshida ◽  
Takahiro Sodeno ◽  
Asao Sakai ◽  
Hidetaka Masahara ◽  
...  
Keyword(s):  
Retinal Detachment ◽  
Cataract Surgery ◽  
Refractive Error ◽  
Prediction Error ◽  
Rhegmatogenous Retinal Detachment ◽  
Control Group ◽  
Macular Disease ◽  
Optical Biometry ◽  
The Difference ◽  
Retrospective Comparative Study

Introduction. The aim of this study was to investigate the postoperative prediction error measured by optical biometry and acoustic biometry in eyes after phacovitrectomy for rhegmatogenous retinal detachment (RRD) with no macular involvement. Methods. Forty-nine eyes of 49 patients (32 male, 17 female; mean age 62.6 ± 7.5 years) with RRD without macular involvement who underwent phacovitrectomy (RRD group) and 49 eyes of 33 patients (21 male, 12 female; mean age 74.1 ± 7.1 years) without macular disease who underwent cataract surgery (control group) were included in this retrospective comparative study. The difference between the preoperative predictive value and the postoperative refractive value was measured both by optical and acoustic biometry and compared in each group. Results. The postoperative refractive error calculated by acoustic biometry was −0.81 ± 0.75D and that calculated by optic biometry was −0.44 ± 0.77D in the RRD group. The postoperative refractive error calculated by acoustic biometry was −0.21 ± 0.64D and that calculated by optic biometry was 0.27 ± 0.71D in the control group. Significant myopic shifts were observed in the RRD group using both acoustic biometry and optic biometry but not in the control group. Conclusion. Phacovitrectomy for RRD with no macular involvement resulted in a significant myopic shift when compared with cataract surgery alone in patients without macular disease when calculated by both acoustic biometry and optic biometry.

Gender differences in biometry prediction error and intra-ocular lens power calculation formula

2014 ◽  
Vol 92 (8) ◽  
pp. 759-763 ◽  
Author(s):  
Anders Behndig ◽  
Per Montan ◽  
Mats Lundström ◽  
Charlotta Zetterström ◽  
Maria Kugelberg
Keyword(s):  
Gender Differences ◽  
Prediction Error ◽  
Power Calculation ◽  
Calculation Formula ◽  
Ocular Lens ◽  
Lens Power ◽  
Lens Power Calculation

scholarly journals Accuracy of Intraocular Lens Power Calculation Formulas for Highly Myopic Eyes

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yichi Zhang ◽  
Xiao Ying Liang ◽  
Shu Liu ◽  
Jacky W. Y. Lee ◽  
Srinivasan Bhaskar ◽  
...  
Keyword(s):  
Intraocular Lens ◽  
Absolute Error ◽  
Power Calculation ◽  
Prediction Errors ◽  
Intraocular Lens Power Calculation ◽  
Iol Power Calculation ◽  
Predictive Error ◽  
Intraocular Lens Power ◽  
Iol Power ◽  
Lens Power

Purpose.To evaluate and compare the accuracy of different intraocular lens (IOL) power calculation formulas for eyes with an axial length (AL) greater than 26.00 mm.Methods.This study reviewed 407 eyes of 219 patients with AL longer than 26.0 mm. The refractive prediction errors of IOL power calculation formulas (SRK/T, Haigis, Holladay, Hoffer Q, and Barrett Universal II) using User Group for Laser Interference Biometry (ULIB) constants were evaluated and compared.Results.One hundred seventy-one eyes were enrolled. The Barrett Universal II formula had the lowest mean absolute error (MAE) and SRK/T and Haigis had similar MAE, and the statistical highest MAE were seen with the Holladay and Hoffer Q formulas. The interquartile range of the Barrett Universal II formula was also the lowest among all the formulas. The Barrett Universal II formulas yielded the highest percentage of eyes within ±1.0 D and ±0.5 D of the target refraction in this study (97.24% and 79.56%, resp.).Conclusions.Barrett Universal II formula produced the lowest predictive error and the least variable predictive error compared with the SRK/T, Haigis, Holladay, and Hoffer Q formulas. For high myopic eyes, the Barrett Universal II formula may be a more suitable choice.

Factors Affecting Prediction Error after Cataract Surgery with Implantation of Various Multifocal IOLs in Patients with Previous Refractive Laser Surgery

2020 ◽  
Author(s):  
Young-Sik Yoo ◽  
Min Chae Kang ◽  
Jongyeop Park ◽  
Hyung-Goo Kwon ◽  
Eui-Sang Chung ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Cataract Surgery ◽  
Prediction Error ◽  
Refractive Surgery ◽  
Predictive Accuracy ◽  
Absolute Error ◽  
Intraocular Lenses ◽  
Group I ◽  
Iol Power ◽  
Corneal Refractive Surgery

Abstract This study aimed to compare the clinical outcomes of implantation of various multifocal intraocular lenses (mIOLs) and the prediction accuracy of two intraocular lens (IOL) power calculation formulas for eyes that underwent previous corneal refractive surgery. Four types of mIOLs (TECNIS Symfony (Group I), AcrySof IQ PanOptix (Group II), LENTIS Mplus (Group III), and TECNIS mIOL (Group IV)) were used and the IOL power was calculated with the two no-history methods, Shammas-PL and Barrett True-K. Visual acuity and refractive outcomes including manifest refraction, prediction error (PE), absolute error (AE), and median absolute error (MedAE) were evaluated at three months after the cataract surgery. For all groups the Barrett True-K formula produced a narrower range of PEs and lower MedAE than Shammas-PL. Eyes of lower predictive accuracy (group B, AE > 0.5D) showed weak uncorrected distance visual acuity resulting from myopic refractive error and target refraction when compared to that of higher predictive accuracy (group A, AE ≤ 0.5 D). Targeting emmetropia using the Barrett True-K is recommended in patients undergoing mIOL implantation with prior corneal refractive surgery. Additionally, history of prior large amount of laser ablation seems to be an important factor related to low predictive accuracy.

scholarly journals Biometric parameters and intra ocular lens power used for cataract eyes in Karnali, Nepal

2014 ◽  
Vol 6 (2) ◽  
pp. 192-196
Author(s):  
Pawan Baral ◽  
Nabin Baral ◽  
Indra Man Maharjan ◽  
Bhoj Raj Gautam ◽  
Madhavendra Bhandari
Keyword(s):  
Cataract Surgery ◽  
Axial Length ◽  
Total Sample ◽  
Ocular Lens ◽  
Biometric Parameters ◽  
Number Of Patients ◽  
Case Files ◽  
Iol Power ◽  
The Mean ◽  
Lens Power

Introduction: The biometric parameters of the eye are measured for the calculation of the intra ocular lens power to be used in cataract surgery. Objective: To report the keratometry reading, axial length and intra ocular lens power used for eyes operated for cataract in Karnali Zone, Nepal, and to compare these findings with those reported in other similar studies. Subjects and methods: The data for the study were retrospectively collected from the case files of patients who had undergone cataract surgery between January 2011 and July 2012 in Karnali Zone, Nepal. These surgeries were performed in an outreach surgical camp organized by the Himalaya Eye Hospital, Nepal, as a part of its annual program. The SPSS 16.0 and Microsoft Excel 2007 software were used for the data analysis.Results: The total number of patients taken for the study was 1055 and the total number of eyes was 1055. There were 530 (50.23%) males and 525 (49.77%) females, with the mean age of 64.34±11.25, ranging from 8 to 98 years.The mean keratometry reading for the total sample was 44.11±1.6 (range, 34.00D to 49.00D). The mean axial length for the total sample was 22.68±0.88 (range, 17.75 to 26.17). The mean IOL power for the total sample was 21.60±1.74 (range, +15.00 to +30.00).Conclusion: The biometric eye parameters of keratometry, axial length and IOL power of this study required for cataract surgery in a Karnali population are similar to those presented in other similar studies from Nepal and abroad.DOI: http://dx.doi.org/10.3126/nepjoph.v6i2.11690Nepal J Ophthalmol 2014; 6(12): 192-196

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 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.

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