The aim of an accurate intraocular lens power calculation is to provide an intraocular lens (IOL) that fits the specific needs and desires of the individual patient. The development of better instrumentation for measuring the eye's axial length (AL) and the use of more precise mathematical formulas to perform the appropriate calculations have significantly improved the accuracy with which the surgeon determines the IOL power.
In order to determine the power of intraocular lens, several values need to be known:
Of these parameters, the first two are measured before the implantation, the third parameter, the ELP, need to be estimated mathematically before the implantation and the last parameter is provided by the manufacturer of the intraocular lens.