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

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.