RESUMEN
To evaluate the efficacy of optimizing of A-constant, the error in prediction was analyzed in three groups of eyes after posterior chamber lens implantation ; 102 eyes with bag placed, 66 eyes with simple sulcus places, and 25 eyes with sulcus placed with transscleral fixation suture. We compared the predictive accuracy of the SRK/T formula using optimized A-constant (bag-placed, sulcus-placed) derived from the 300 eyes with Holladay and SRK/T using original surgeon factor and A-constant. The SRK/T formula with optimized A-constant has a better mean relative, absolut, and standard error and has a better range of IOL prediction error, which was more accurate than other formulas without optimizing. In this study it is our recommendation that each surgeon use a different optimized A-constants for sulcus or bag placement to enhance the predictability of the postoperative refraction.