Three-Dimensional Quantitative Description of the Implantable Collamer Lens in the Ocular Anterior Segment of Patients With Myopia

PURPOSE: To describe the 3-dimensional (3D) location of the implantable collamer lens (ICL) quantitatively in the posterior ocular chamber of patients with myopia.DESIGN: Cross-sectional study.METHODS: To obtain visualization models before and after mydriasis, an automatic 3D imaging method based on swept-source optical coherence tomography was cre-ated. Parameters like the ICL lens volume (ILV), the tilt of the ICL and crystalline lens, the vault distribution index, and topographic maps were evaluated to describe the ICL location. Using a paired sample t test and the Wilcoxon signed rank test, the difference between non-mydriasis and postmydriasis conditions was compared.RESULTS: The study investigated 32 eyes from 20 pa-tients. The 3D central vault did not differ significantly before ( P = .994) or after mydriasis ( P = .549) com-pared with the 2D central vault. After mydriasis, the 5 -mm ILV decreased by 0.85 mm2 ( P = .016), and the vault distribution index increased significantly ( P = .001). The ICL and the crystalline lens exhibited tilt (nonmydriasis: ICL total tilt 3.78 +/- 1.85 degrees, lens total tilt 4.03 +/- 1.53 degrees; postmydriasis: ICL total tilt 3.84 +/- 1.56 degrees, lens total tilt 4.09 +/- 1.64 degrees). The phe-nomenon of asynchronous tilt of the ICL and lens was found in 5 eyes, leading to the spatially asymmetric dis-tribution of the ICL-lens distance.CONCLUSION: The 3D imaging technique provided ex-haustive and reliable data for the anterior segment. The visualization models offered multiple perspectives on the ICL in the posterior chamber. Before and after mydria-sis, the intraocular ICL position was described by the 3D parameters. (Am J Ophthalmol 2023;252: 59-68. (c) 2023 Elsevier Inc. All rights reserved.)