Abstract
Purpose:
To demonstrate the need for integration of the spherical power calculation and the recommended toric correction in IOL calculation and to offer a practical implementation.
Methods:
A review of the methods offered by a majority of manufacturers of toric IOLs and followed almost universally by surgeons was performed.<br /> Calculations of IOL power and toricity based on these methods was analyzed and executed alongside a theoretical analysis of the underlying methods and algorithms.
Results:
A number of cases were identified where the standard sequential methods resulted in suboptimal choice of lenses. These were then calculated with our Universal Calculator in simultaneous mode and resulted in selections demonstrably preferable to those of the standard methods. The dominant methodologies were identified as a form of "greedy algorithms" which are known to have the possibility of being suboptimal.
Conclusions:
The usual sequential method of toric IOL is suboptimal. A method and an implementation providing better choices is demonstrated.