Comparison of the Kane formula with existing formulas for intraocular lens power selection

ObjectiveTo compare the accuracy of a new intraocular lens (IOL) power formula (Kane formula) with existing formulas using IOLMaster, predominantly model 3, biometry (measures variables axial length, keratometry and anterior chamber depth) and optimised lens constants. To compare the accuracy of three new or updated IOL power formulas (Kane, Hill-RBF V.2.0 and Holladay 2 with new axial length adjustment) compared with existing formulas (Olsen, Barrett Universal 2, Haigis, Holladay 1, Hoffer Q, SRK/T).Methods and analysisA single surgeon retrospective case review was performed from patients having uneventful cataract surgery with Acrysof IQ SN60WF IOL implantation over 11 years in a Melbourne private practice. Using optimised lens constants, the predicted refractive outcome for each formula was calculated for each patient. This was compared with the actual refractive outcome to give the prediction error. Eyes were separated into subgroups based on axial length as follows: short (≤22.0 mm), medium (>22.0 to <26.0 mm) and long (≥26.0 mm).ResultsThe study included 846 patients. Over the entire axial length range, the Kane formula had the lowest mean absolute prediction error (p<0.001, all formulas). The mean postoperative difference from intended outcome for the Kane formula was −0.14+0.27×1 (95% LCL −1.52+0.93×43; 95% UCL +0.54+1.03×149). The formula demonstrated the lowest absolute error in the medium axial length range (p<0.001). In the short and long axial length groups, no formula demonstrated a significantly lower absolute mean prediction error.ConclusionUsing three variables (AL, K, ACD), the Kane formula was a more accurate predictor of actual postoperative refraction than the other formulae under investigation. There were not enough eyes of short or long axial length to adequately power statistical comparisons within axial length subgroups.

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Anterior chamber depth, lens thickness and intraocular lens calculation formula accuracy: nine formulas comparison

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2020-317822 ◽

2020 ◽

pp. bjophthalmol-2020-317822

Author(s):

Diogo Hipólito-Fernandes ◽

Maria Elisa Luís ◽

Rita Serras-Pereira ◽

Pedro Gil ◽

Vitor Maduro ◽

...

Keyword(s):

Anterior Chamber ◽

Intraocular Lens ◽

Prediction Error ◽

Anterior Chamber Depth ◽

Case Series ◽

Absolute Error ◽

Power Calculation ◽

Retrospective Case ◽

Lens Thickness ◽

Mean Prediction Error

Background/AimsTo investigate the influence of anterior chamber depth (ACD) and lens thickness (LT) on 9 intraocular lens (IOL) power calculation formulas accuracy, in patients with normal axial lengths.MethodsRetrospective case series, including patients having uncomplicated cataract surgery with insertion of a single IOL model, divided into three groups according to preoperative ACD. Each group was further subdivided into three subgroups, according to the LT. Using optimised constants, refraction prediction error was calculated for Barrett Universal II, Emmetropia Verifying Optical (EVO) V.2.0, Haigis, Hill-RBF V.2.0, Hoffer Q, Holladay 1, Kane, PEARL-DGS and SRK/T formulas. Mean prediction error, mean and median absolute error (MedAE) and the percentage of eyes within ±0.25D, ±0.50D and ±1.00D were also calculated.ResultsThe study included 695 eyes from 695 patients. For ACD ≤3.0 mm and ≥3.5 mm, mean prediction error of SRK/T, Hoffer Q and Holladay 1 was significantly different from 0 (p<0.05). PEARL-DGS, Kane, EVO V.2.0 and Barrett Universal II were more accurate than the Hoffer Q in ACD ≤3.0 mm (p<0.05). Kane, PEARL-DGS, EVO V.2.0 and Barrett Universal II revealed the lowest variance of mean and MedAE by ACD and LT subgroup. Haigis and Hill-RBF V.2.0 were significantly influenced by LT, independently of the ACD, with a myopic shift with thin lenses and a hyperopic shift with thick lenses (p<0.05).ConclusionNew generation formulas, particularly Kane, PEARL-DGS and EVO V.2.0, seem to be more reliable and stable even in eyes with extreme ACD-LT combinations.

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Assessment of the Influence of Keratometry on Intraocular Lens Calculation Formulas in Long Axial Length Eyes

10.21203/rs.3.rs-639671/v1 ◽

2021 ◽

Author(s):

Shengjie Yin ◽

Chengyao Guo ◽

Kunliang Qiu ◽

Tsz Kin Ng ◽

Yuancun Li ◽

...

Keyword(s):

Intraocular Lens ◽

Axial Length ◽

Case Series ◽

Absolute Error ◽

Power Calculation ◽

Prediction Errors ◽

Retrospective Case ◽

Iol Power Calculation ◽

Iol Power ◽

Intraocular Lens Calculation

Abstract Purpose: Hyperopic surprises tend to occur in axial myopic eyes and other factors including corneal curvature have rarely been analyzed in cataract surgery, especially in eyes with long axial length (≥ 26.0 mm). Thus, the purpose of our study was to evaluate the influence of keratometry on four different formulas (SRK/T, Barrett Universal II, Haigis and Olsen) in intraocular lens (IOL) power calculation for long eyes.Methods: Retrospective case-series. 180 eyes with axial length (AL) ≥ 26.0 mm were divided into 3 keratometry (K) groups: K ≤ 42.0 D (Flat), K ≥ 46.0 D (Steep), 42.0 < K < 46.0 D (Average). Prediction errors (PE) were compared between different formulas. Multiple regression analysis was performed to investigate factors associated with the PE.Results: The mean absolute error was higher for all evaluated formulas in Steep group (ranging from 0.66 D to 1.02 D) than the Flat (0.34 D to 0.67 D) and Average groups (0.40 D to 0.74D). The median absolute errors predicted by Olsen formula were significantly lower than that predicted by Haigis formula (0.42 D versus 0.85 D in Steep and 0.29 D versus 0.69 D in Average) in Steep and Average groups (P = 0.012, P < 0.001, respectively). And the Olsen formula demonstrated equal accuracy to the Barrett II formula in Flat and Average groups. The predictability of the SRK/T formula was affected by the AL and K, while the predictability of Olsen and Haigis formulas was affected by the AL only. Conclusions: Steep cornea has more influence on the accuracy of IOL power calculation than the other corneal shape in long eyes. Overall, both the Olsen and Barrett Universal II formulas are recommended in long eyes with unusual keratometry.

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Comparison of the accuracy of 11 intraocular lens power calculation formulas

European Journal of Ophthalmology ◽

10.1177/1120672120962030 ◽

2020 ◽

pp. 112067212096203

Author(s):

David Carmona-González ◽

Alfredo Castillo-Gómez ◽

Carlos Palomino-Bautista ◽

Marta Romero-Domínguez ◽

María Ángeles Gutiérrez-Moreno

Keyword(s):

Intraocular Lens ◽

Case Series ◽

University Hospital ◽

Power Calculation ◽

Refractive Outcome ◽

Retrospective Case ◽

Intraocular Lens Power Calculation ◽

Iol Power Calculation ◽

Refractive Outcomes ◽

Iol Power

Purpose To compare the accuracy of 11 intraocular lens (IOL) power calculation formulas (SRK-T, Hoffer Q, Holladay I, Haigis, Holladay II, Olsen, Barrett Universal II, Hill-RBF, Ladas Super formula, EVO and Kane). Setting Private university hospital (QuironSalud, Madrid, Spain). Design Retrospective case series Methods Data were compiled from 481 eyes of 481 patients who had undergone uneventful cataract surgery with IOL insertion. Preoperative biometric measurements were made using an IOL Master® 700. Respective ULIB IOL constants ( http://ocusoft.de/ulib/c1.htm ) for each of 4 IOL models implanted were used to calculate the predictive refractive outcome for each formula. This was compared with the actual refractive outcome determined 3 months postoperatively. The primary outcome was mean absolute prediction error (MAE). The study sample was divided according to axial length (AL) into three groups of eyes: short (⩽22.00 mm), normal (22.00–25.00 mm) and long (⩾25.00 mm). Results The Barrett Universal II and Haigis formulas yielded the lowest MAEs over the entire AL range ( p < .01, except EVO) as well as in the long ( p < .01, all formulas) and normal ( p < .01, except Haigis, Holladay II, Olsen and LSF) eyes. In the short eyes, the lower MAEs were provided by Haigis and EVO ( p < .01 except Hoffer Q, SRK/T and Holladay I). Conclusions Barrett Universal II was the most accurate for IOL power calculation in the normal and long eyes. For short eyes, the formulas Haigis and EVO seem best at predicting refractive outcomes.

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Accuracy of common IOL power formulas in 611 eyes based on axial length and corneal power ranges

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2020-315882 ◽

2020 ◽

pp. bjophthalmol-2020-315882

Author(s):

Veronika Röggla ◽

Achim Langenbucher ◽

Christina Leydolt ◽

Daniel Schartmüller ◽

Luca Schwarzenbacher ◽

...

Keyword(s):

Axial Length ◽

Prediction Error ◽

Absolute Error ◽

Power Calculation ◽

Corneal Power ◽

Biometric Parameters ◽

Iol Power Calculation ◽

Iol Power ◽

Median Absolute Error ◽

Axial Eye Length

AimsTo provide clinical guidance on the use of intraocular lens (IOL) power calculation formulas according to the biometric parameters.Methods611 eyes that underwent cataract surgery were retrospectively analysed in subgroups according to the axial length (AL) and corneal power (K). The predicted residual refractive error was calculated and compared to evaluate the accuracy of the following formulas: Haigis, Hoffer Q, Holladay 1 and SRK/T. Furthermore, the percentages of eyes with ≤±0.25, ≤±0.5 and 1 dioptres (D) of the prediction error were recorded.ResultsThe Haigis formula showed the highest percentage of cases with ≤0.5 D in eyes with a short AL and steep K (90%), average AL and steep cornea (73.2%) but also in long eyes with a flat and average K (65% and 72.7%, respectively). The Hoffer Q formula delivered the lowest median absolute error (MedAE) in short eyes with an average K (0.30 D) and Holladay 1 in short eyes with a steep K (Holladay 1 0.24 D). SRK/T presented the highest percentage of cases with ≤0.5 D in average long eyes with a flat and average K (80.5% and 68.1%, respectively) and the lowest MedAE in long eyes with an average K (0.29 D).ConclusionOverall, the Haigis formula shows accurate results in most subgroups. However, attention must be paid to the axial eye length as well as the corneal power when choosing the appropriate formula to calculate an IOL power, especially in eyes with an unusual biometry.

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Intraocular lens power calculation formulas accuracy in combined phacovitrectomy: an 8-formulas comparison study

International Journal of Retina and Vitreous ◽

10.1186/s40942-021-00315-7 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Diogo Hipólito-Fernandes ◽

Maria Elisa Luís ◽

Diogo Maleita ◽

Pedro Gil ◽

Vitor Maduro ◽

...

Keyword(s):

Intraocular Lens ◽

Prediction Error ◽

Retrospective Chart Review ◽

Absolute Error ◽

Power Calculation ◽

Myopic Shift ◽

Iol Power ◽

Group 3 ◽

Group 2 ◽

Group 1

Abstract Background Our study aimed to assess and compare the accuracy of 8 intraocular lens (IOL) power calculation formulas (Barrett Universal II, EVO 2.0, Haigis, Hoffer Q, Holladay 1, Kane and PEARL-DGS) in patients submitted to combined phacovitrectomy for vitreomacular (VM) interface disorders. Methods Retrospective chart review study including axial-length matched patients submitted to phacoemulsification alone (Group 1) and combined phacovitrectomy (Group 2). Using optimized constants in both groups, refraction prediction error of each formula was calculated for each eye. The optimised constants from Group 1 were also applied to patients of Group 2 – Group 3. Outcome measures included the mean prediction error (ME) and its standard deviation (SD), mean (MAE) and median (MedAE) absolute errors, in diopters (D), and the percentage of eyes within ± 0.25D, ± 0.50D and ± 1.00D. Results A total of 220 eyes were included (Group 1: 100; Group 2: 120). In Group 1, the difference in formulas absolute error was significative (p = 0.005). The Kane Formula had the lowest MAE (0.306) and MedAE (0.264). In Group 2, Kane had the overall best performance, followed by PEARL-DGS, EVO 2.0 and Barrett Universal II. The ME of all formulas in both Groups 1 and 2 were 0.000 (p = 0.934; p = 0.971, respectively). In Group 3, a statistically significant myopic shift was observed for each formula (p < 0.001). Conclusion Surgeons must be careful regarding IOL power selection in phacovitrectomy considering the systematic myopic shift evidenced—constant optimization may help eliminating such error. Moreover, newly introduced formulas and calculation methods may help us achieving increasingly better refractive outcomes both in cataract surgery alone and phacovitrectomy.

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

10.21203/rs.2.19177/v1 ◽

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.

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CATARACT SURGERY;

The Professional Medical Journal ◽

10.29309/tpmj/2008.15.03.2833 ◽

2008 ◽

Vol 15 (03) ◽

pp. 387-391

Author(s):

EJAZ AHMAD JAVED ◽

MUHAMMAD SULTAN

Keyword(s):

Cataract Surgery ◽

Axial Length ◽

Previous History ◽

Anterior Chamber Depth ◽

Case Series ◽

Retrospective Case ◽

Axis Ii ◽

Corneal Scarring ◽

History Of ◽

Iol Power

Objectives: To describe the variation of axial length in patients undergoingcataract surgery. Study design: A retrospective case series. Place and duration of study: At OpthalmologicalDepartment, Allied Hospital, PMC, Faisalabad from May 2006 to June 2007. Patients and methods: The axial lengthof 566 patients who were admitted for cataract surgery were measured with A. scan (Axis II, Quantel). The elevenpatients with age below 15 years and above 90 years and with history of trauma, corneal scarring were excluded. Sothere were 555 patients for this study. A careful history of diabetes mellitus, hypertension, trauma, previous history ofsurgery, glaucoma and uveitis was taken, and slit lamp examination, tonometry, pupillary reactions, perception andprojection of light was done. The data collected was entered in specially designed Performa. An average of tenreadings of axial lengths with A-Scan for each patient was taken. Results: Out of 555 patients, there were 350 male(63.06%) and 205 female (36.94%) patients. There were 250(45.05%) patients having age between 46 to 60 years.There were 27(4.86%) patients having age between 15 to 30 years and the same number 27(4.86%) of patients wasseem having age between 76 to 90 years. The most of the patients 273(49.18%) had axial length between 23mm to25 mm. There were only 3 patients with axial length between 29.01 to 31 mm. There were a significant number ofpatients, 230(41.45%) having axial length between 21.01 to 23mm. Conclusion: The biometry depends upon axiallength, kratometry and anterior chamber depth. Most of the formulae supposed for IOL calculations depend upon onlytwo factors, the axial length and the keratometry. In our community, short and long eyes are very rare and so SRK-Tformula for IOL calculations provides satisfactory postoperative results. The axial length carries more importance asits variation causes a gross change in IOL power and postoperative refractive errors.

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Intraocular lens power calculation formula accuracy: Comparison of 12 formulas for a trifocal hydrophilic intraocular lens

European Journal of Ophthalmology ◽

10.1177/1120672120980690 ◽

2020 ◽

pp. 112067212098069

Author(s):

Carlos Rocha-de-Lossada ◽

Elvira Colmenero-Reina ◽

David Flikier ◽

Francisco-Javier Castro-Alonso ◽

Alvaro Rodriguez-Raton ◽

...

Keyword(s):

Intraocular Lens ◽

Axial Length ◽

Absolute Error ◽

Power Calculation ◽

Intraocular Lens Power Calculation ◽

Accuracy Comparison ◽

Intraocular Lens Power ◽

Iol Power ◽

Lens Power ◽

Lens Power Calculation

Purpose: To evaluate the accuracy of 12 intraocular lens (IOL) power formulas; Barrett Universal II, Emmetropia Verifying Optical (EVO), Haigis, Hill-Radial Basis Function (RBF), Hoffer Q, Holladay I, Kane, Ladas Super Formula, Olsen Lenstar, Panacea, Pearl-DGS, Sanders-Retzlaff-Kraff/theoretical (SRK/T). In addition, an analysis of the efficacy as a function of the axial length was performed. Methods: About 171 from 93 patients: 68 male eyes and 103 female eyes. Twelve IOL power formula calculations were studied with one IOL platform (trifocal hydrophilic IOL, FineVision Micro F), one biometer (Lenstar LS 900), one topographer (CSO Sirius Topographer), one surgeon, and one optometrist. Optimization were determined to be zeroed mean refractive prediction error. Mean error (ME), mean absolute error (MAE), median absolute error (MedAE) and refractive accuracy within ±1.00 D was calculated. Axial length was split in short and medium eyes. Results: One hundred and seventy eyes were included. Formulas were ranked by percentage within ±0.50 diopters and MAE (D). Among all eyes, Olsen 86.55% (0.273 D) and Barrett Universal II 86.55% (0.285D). For short eyes (<22.5 mm), Olsen 90.70% (0.273 D) and Kane 90.70% (0.225 D). For medium eyes, Barrett 89.34% (0.237 D) and Pearl 86.89% (0.263 D). Conclusion: Olsen and Barrett formula obtained excellent accuracy for overall eyes. Kane and Olsen formula obtained the best results in short eyes. For medium axial length Barrett formula achieved the best accuracy results.

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Gradient Boosting Decision Tree Algorithm for the Prediction of Postoperative Intraocular Lens Position in Cataract Surgery

10.1101/2020.08.26.20181156 ◽

2020 ◽

Author(s):

Tingyang Li ◽

Kevin Yang ◽

Joshua Stein ◽

Nambi Nallasamy

Keyword(s):

Decision Tree ◽

Cataract Surgery ◽

Intraocular Lens ◽

Anterior Chamber Depth ◽

Absolute Error ◽

Gradient Boosting ◽

Tree Model ◽

Lens Position ◽

Iol Power ◽

Testing Set

Purpose: To develop a method for predicting postoperative anterior chamber depth (ACD) in cataract surgery patients based on preoperative biometry, demographics, and intraocular lens (IOL) power. Methods: Patients who underwent cataract surgery and had both preoperative and postoperative biometry measurements were included. Patient demographics and IOL power were collected from the Sight Outcomes Research Collaborative (SOURCE) database. A gradient boosting decision tree model was developed to predict the postoperative ACD. The mean absolute error (MAE) and median absolute error (MedAE) were used as evaluation metrics. The performance of the proposed method was compared to five existing formulas. Results: 847 patients were assigned randomly in a 4:1 ratio to a training/validation set (678 patients) and a testing set (169 patients). Using preoperative biometry and patient sex as predictors, the presented method achieved an MAE of 0.106 (SD: 0.098) on the testing set, and a MedAE of 0.082. MAE was significantly lower than that of the five existing methods (p < 0.01). When keratometry was excluded, our method attained an MAE of 0.123 (SD: 0.109), and a MedAE of 0.093. When IOL power was used as an additional predictor, our method achieved an MAE of 0.105 (SD: 0.091) and a MedAE of 0.080. Conclusions: The presented machine learning method achieved accuracy surpassing that of previously reported methods in the prediction of postoperative ACD. Translational Relevance: Increasing accuracy of postoperative ACD prediction with the presented algorithm has the potential to improve refractive outcomes in cataract surgery.

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