IOL Tilt and Decentration Estimation from 3 Dimensional Reconstruction of OCT Image

Abstract

Purpose: To evaluate intraocular lens (IOL) tilt and decentration by anterior segment optical coherence tomography (AS-OCT) using 3-dimensional (3D) reconstruction method. Design: Prospective observational case series. Participants: Thirty-nine patients (39 eyes) were included. Methods: The IOL positions of all eyes were examined by AS-OCT. Images were obtained in 4 axes (0-180 degrees, 45-225 degrees, 90-270 degrees, and 135-315 degrees) using the quadrant-scan model. The cross-sectional images were analyzed with MATLAB software. Main Outcome Measures: The angle (θ) between the reference pupillary plane and the IOL plane, the distances between the center points of the pupil circle and the IOL on the x-axis (dx) and y-axis (dy) and the spatial distance (ds) were calculated after 3D-reconstruction. Results: The mean angle (θ) between the pupillary plane and the IOL plane was 2.94±0.99 degrees. The mean IOL decentration of dx and dy was 0.32±0.26 mm and 0.40±0.27 mm, respectively. The ds of the IOL decentration was 0.56±0.31 mm. There was no significant correlation between the ocular residual astigmatism (ORA) and the tilted angle or the decentration distance. There was a significant correlation between the ORA and total astigmatism (r = 0.742, P<0.001). There was no significant correlation between the postoperative best corrected visual acuity (BCVA) and the ORA (r = 0.156; P = 0.344), total astigmatism (r = 0.012; P = 0.942), tilted angle (θ; r = 0.172; P = 0.295) or decentration distance (dx: r = 0.191, P = 0.244; dy: r = 0.253, P = 0.121; ds: r = 0.298, P = 0.065). Conclusions: AS-OCT can be used as an alternative for the analysis of IOL tilt and decentration using 3D-reconstruction. © 2013 Wang et al.