PUBLICATION EXCLUSIVE: How to adjust IOL power in unusual cataract cases

With newly developed methods of IOL power calculation, we are approaching 90% or higher accuracy of being within 0.5 D of the intended refractive target. The Barrett Universal formula uses improved algorithms, the Hill-RBF method relies on artificial intelligence with large data sets, and the Ladas Super Formula incorporates both novel methods as well as crowd-sourced big data to continuously hone its results. But even with these techniques of calculation, there is still a need to adjust the IOL power in unusual cataract cases.The A-constant of the IOL reflects many variables such as effective lens position, lens geometry, refractive index and more. If we are planning to implant a particular IOL in the capsular bag but then decide to switch to a different IOL, we may need to adjust the power in order to keep the same refractive outcome. This may be the case if a particular power of a specific IOL is not available or if we decide to switch from one brand to another to better match the patient’s tissue.