Lens and IOL Tilt

Tilt can be quantified by two principal methods either by cross-sectional scans of the anterior segment such as Scheimpflug imaging, optical coherence tomography (OCT), and ultrasound biomicroscopy (UBM), or by assessing the Purkinje reflexes. IOL tilt affects the visual quality, the final refraction, and the amount of residual astigmatism. Tilt accounts for more than 10° of the error in toric IOL power calculation and this value increases to almost 20%, if combined with angle kappa. Predicting tilt and taking it into account would significantly improve toric IOL power calculation. The factors influencing tilt include the capsulorhexis, pseudo-exfoliation, IOL material and design, after-cataract changes, and combined surgeries.