![]() Furthermore, anterior chamber depth (ACD) and lens thickness (LT) have also been found to be negatively correlated with crystalline lens tilt ( 16). A greater tilt of both crystalline lenses and IOLs has been reported to be associated with shorter AL ( 16). Moreover, axial length (AL) may be another critical factor that affects the tilt and decentration of crystalline lenses and IOLs. demonstrated that preoperative crystalline lens tilt was strongly correlated with IOL tilt (r=0.707) ( 16). reported that the tilt directions of crystalline lenses and IOLs were strongly correlated, while their magnitudes of tilt were more weakly correlated ( 15). Compared with the pupil center, the visual line is considered a better reference for assessing IOL tilt and decentration, because it is not affected by the shape of the pupil.Īlthough several studies have found that the magnitude and direction of tilt of postoperative IOLs were correlated with the tilt of preoperative crystalline lenses, these results were inconsistent ( 15, 16). It can clearly outline the crystalline lens or IOL and generate three-dimensional (3D) results of tilt and decentration using the visual line as a reference. CASIA2, a novel second generation of AS-OCT, has been demonstrated to measure the tilt and decentration of crystalline lenses and IOLs automatically and quantitatively with high repeatability ( 14). The accuracy and repeatability of measurements therefore depend on the alignment and quality of images. However, none of the above methods can measure the tilt and decentration of crystalline lenses and IOLs automatically, which need to be combined using image processing software. Scheimpflug photography, Purkinje images, and anterior segment optical coherence tomography (AS-OCT) have been used in the past to measure the tilt and decentration of IOLs ( 8- 13). ![]() To achieve better postoperative visual quality, it is necessary to understand the main factors that contribute to IOL tilt and decentration after cataract surgery. Tilt and decentration may cause fewer predictable astigmatisms for toric IOLs and induce larger comas for multifocal IOLs ( 4- 7). Especially for toric and multifocal IOLs, their optical performances were more sensitive to tilt and decentration. Previous studies have found that an IOL tilt greater than 7° or decentration greater than 0.4 mm affects visual quality after IOL implantation by increasing wavefront aberrations, such as astigmatism and high-order aberrations (HOA) ( 1- 3). Misalignment of the intraocular lens (IOL) is an important risk factor for the deterioration of visual quality after cataract surgery. Keywords: Crystalline lenses intraocular lens (IOL) tilt decentration axial length (AL) The tilt and decentration of IOLs will be greater in patients with larger tilt and decentration of crystalline lenses, or shorter and longer AL. AL was the factor most highly associated with IOL decentration (R 2=0.332, P<0.001), rather than crystalline lens decentration (R 2=0.214, P<0.001).Ĭonclusions: The position of the preoperative crystalline lens and AL were the critical determinants of IOL tilt and decentration. Additionally, crystalline lens decentration and AL explained 54.6% of the variability in IOL decentration. The strongest determinant of IOL tilt was preoperative crystalline lens tilt (R 2=0.512, P<0.001), followed by AL (R 2=0.154, P=0.003). There were no significant differences in magnitude, direction of tilt, or decentration between crystalline lenses and IOLs. ![]() Results: The mean tilt and decentration of the patients’ preoperative crystalline lenses were 4.90°☑.81° and 0.21☐.02 mm, and the mean tilt and decentration of IOLs were 4.75°☑.66° and 0.21☐.02 mm, respectively. The tilt and decentration of patients’ preoperative crystalline lenses and postoperative IOLs, as well as crystalline lens thickness (LT), were measured using AS-OCT before surgery and 1 week after surgery. Axial length (AL) was measured with IOL Master 700. Methods: Fifty-six patients who underwent phacoemulsification with IOL implantation in one eye were continuously enrolled in this cohort study.
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