Prediction of Effective Lens Position by Reference to the Preoperative Axial Length

Purpose: We derived optimal formulae permitting effective lens position (ELP) for patients differing in terms of their preoperative axial lengths as revealed by partial coherence interferometry. Methods: We included 736 eyes from 736 patients who underwent conventional cataract surgery at Yeouido St. Mary's Hospital. The preoperative axial length (AL), corneal power (CP), and anterior chamber depth (ACD) measured via partial coherence interferometry served as independent variables for ELP prediction. The 736 eyes were divided into seven groups differing by 1.0-mm intervals in terms of the preoperative axial length. We sought correlations between the independent variables and the ELP, and defined the combinations that best predicted the ELPs of the seven groups. Results: The CP correlated significantly with the ELP for eyes with AL between 22.0 and 25.0 mm (all p < 0.01) and the ACD correlated significantly with the ELP for eyes with AL between 23.0 and 26.0 mm (all p < 0.01). Although a regression equation featuring all of the AL, ACD, and CP best predicted the ELP for the total of 736 eyes (p < 0.001), the optimal combination varied by the preoperative AL. Conclusions: The effects of CP, ACD, and AL on ELP vary by the preoperative AL. The optimal combination of preoperative variables predicting ELP thus varies as that parameter changes.