Comparison of 9 intraocular lens power calculation formulas

Different formulas work best with different optical biometers

A study comparing the predictive accuracy nine different intraocular lens calculation formulas using two optical biometers showed that the formulas gave different results depending on which machine’s measurements are used. In a retrospective series of eyes, the Olsen standalone formula performed the best out of nine formulas at all axial lengths when the LenStar optical low-coherence reflectometer (OLCR) measurements were used. If only partial coherence interferometry measurements (without lens thickness) were available, the Barrett Universal II performed the best and the Olsen formula performed the worst. The study also found that the pre-installed version of Olsen was not as good as the standalone version and that the Holladay 2 formula performed better when the preoperative refraction data was omitted.