Biometric data

(15,00 / 40,00)
(0,00 / 7,00)
(1,00 / 10,00)
(6,00 / 18,00)

Keratometric data

(n = 1.3375)
(-2,00 / -10,00)

(-30.00 / +30.00)


IOL power (D)

Refraction postop (D)

Powered by David Carmona Gonzalez


What is Karmona® v1.0?

Karmona® IOL power calculation is a new calculation method, based on artificial intelligence, to calculate the power of the intraocular lens implanted in lens surgery. It is based on two non-lineal regression mathematical models that have been ensembled in a final model considering stacking method, cross validation and generalized linear model training techniques, to enhance the prediction. Obtaining the following performance metrics with the test sample (n = 100 eyes):

                                                                                      R² = 0.995 , MAE = 0.24 D.

About Karmona®

Karmona® IOL power calculation is designed and programmed in Shiny-RStudio (Version 1.1.423) by David Carmona Gonzalez (Spain-Madrid, 2018-2021). It is optimized for anterior keratometry with IOL Master® 700 (Carl Zeiss Meditec, Jena, Germany) and posterior keratometry with Pentacam® (Oculus Optikgeräte GmbH, Wetzlar, Germany), however it can be used with measurements from any other devices. The required biometric variables that Karmona® works with are AXL, ACD, WTW, ANTERIOR KM (1.3375) and the optional ones are LT and POSTERIOR KM. It uses the A constant as the intraocular lens constant, recognizable for everyone and easy to obtain. Unlike its competitors, Karmona® has been developed only with a database of 386 eyes, but as any other ‘Artificial Intelligence based model’, it is constantly learning, so its predictive capacity is improving continuously. It is remarkable that Karmona® has been designed to increase the accuracy in extreme and atypical eyes. In this respect, there is a paper published to see corresponding clinical results (


As the author of Karmona® IOL Power Calculation v1.0, I assume no responsibility for the refractive outcomes obtained with your patients. The information provided in this website is without warranty of any kind. The selection of the IOL is the sole responsibility of the surgeon, based on personal criteria and it depends on each case.

Terms of use

Karmona® is registered and under license of intellectual property. Any attempt to copy, modify or decompile will be prosecuted by law.

2021 Karmona® IOL Power Calculation. All rights reserved.
Madrid - Spain


If you have any suggestions, questions or comments do not hesitate to contact me.

My name is David Carmona Gonzalez and I am optometrist. My email address and place of work:

Hospital Universitario QuironSalud Madrid

Calle Diego de Velazquez,1.

28223 - Pozuelo de Alarcon

Madrid (Spain)