Comparison of Hill-radial basis function, Barrett Universal and current third generation formulas for the calculation of intraocular lens power during cataract surgery

Purpose: The aim of this study was to compare the accuracy of Barrett Universal II and Hill-Radial Basis Function with other four popular formulas for the calculation of intraocular lens power in high myopic eyes. Methods: A total of 56 eyes with an axial length of more than 26.0 mm were retrospectively reviewed. Six intraocular lens power calculation methods, including Barrett Universal II, Hill-Radial Basis Function, SRK/T, Haigis, Holladay 2 and Holladay 1, were evaluated. The difference between the postoperative actual refraction and the refraction predicted by the six methods was evaluated as the prediction error. The absolute prediction error was also calculated. Results: The mean numerical prediction error ± standard deviation of the six intraocular lens power calculation methods, in order of lowest to highest, was Barrett Universal II (0.37 ± 0.54 D), Hill-Radial Basis Function (0.40 ± 0.56 D), SRK/T (0.44 ± 0.56 D), Haigis (0.53 ± 0.54 D), Holladay 2 (0.88 ± 0.62 D) and Holladay 1 (1.00 ± 0.60 D). The median absolute errors predicted by the Barrett (0.46 D), Hill-Radial Basis Function (0.47 D), SRK/T (0.53 D) and Haigis (0.58 D) were significantly lower than those of the Holladay 1 (0.90 D) and Holladay 2(1.10 D; all p < 0.001). There was no significant difference among the median absolute errors of Barrett, Hill-Radial Basis Function, SRK/T and Haigis (all p > 0.05). Conclusion: The prediction errors differed for each method in the selection of intraocular lens power for the long eyes. In terms of overall accuracy, the Barrett Universal II formula provided the lowest prediction error. The Hill-Radial Basis Function method was comparable to the theoretical formulas, such as SRK/T and Haigis.

Download Full-text

Simple regression formula for intraocular lens power adjustment in eyes requiring cataract surgery after excimer laser photoablation

Yearbook of Ophthalmology ◽

10.1016/s0084-392x(08)70005-4 ◽

2007 ◽

Vol 2007 ◽

pp. 2-3

Author(s):

R. Tipperman

Keyword(s):

Cataract Surgery ◽

Excimer Laser ◽

Intraocular Lens ◽

Power Adjustment ◽

Regression Formula ◽

Intraocular Lens Power ◽

Lens Power ◽

Simple Regression

Download Full-text

Accuracy of the Hill–radial basis function method and the Barrett Universal II formula

European Journal of Ophthalmology ◽

10.1177/1120672120902952 ◽

2020 ◽

pp. 112067212090295 ◽

Cited By ~ 2

Author(s):

Gabor Nemeth ◽

Laszlo Modis

Keyword(s):

Radial Basis Function ◽

Intraocular Lens ◽

Basis Function ◽

Function Method ◽

Theoretical Formula ◽

Refractive Errors ◽

Radial Basis ◽

The Mean ◽

The Hill ◽

Radial Basis Function Method

Purpose: The aim was to assess the postoperative results of a biometric method using artificial intelligence (Hill–radial basis function 2.0), and data from a modern formula (Barrett Universal II) and the Sanders–Retzlaff–Kraft/Theoretical formula. Methods: Phacoemulsification and biconvex intraocular lens implantation were performed in 186 cataractous eyes. The diopters of intraocular lens were established with the Hill–radial basis function method, based on biometric data obtained using the Aladdin device. The required diopters of the intraocular lens were also calculated by the Barrett Universal II formula and with the Sanders–Retzlaff–Kraft/Theoretical formula. The differences between the manifest postoperative refractive errors and the planned refractive errors were calculated, as well as the percentage of eyes within ±0.5 D of the prediction error. The mean- and the median absolute refractive errors were also determined. Results: The mean age of the patients was 70.13 years (SD = 10.67 years), and the mean axial length was 23.47 mm (range = 20.72–28.78 mm). The percentage of eyes within a prediction error of ±0.5 D was 83.62% using the Hill–radial basis function method, 79.66% with the Barrett Universal II formula, and 74.01% in the case of the Sanders–Retzlaff–Kraft/Theoretical formula. The mean- and the median absolute refractive errors were not statistically different. Conclusion: Clinical success was the highest when using the biometric method, based on pattern recognition. The results obtained using Barrett Universal II came a close second. Both methods performed better compared to a traditionally used formula.

Download Full-text