Effects of Implantable Collamer Lens V4c Placement on Iridocorneal Angle Measurements by Fourier-Domain Optical Coherence Tomography

PURPOSE: To assess by Fourier-domain optical coherence tomography (FDOCT) changes produced in iridocorneal angle measurements in patients undergoing Visian Implantable Collamer Lens (ICL) V4c (STAAR Surgical AG) placement. DESIGN: Prospective interventional case series. METHODS: In 50 eyes of 25 myopic subjects consecutively scheduled for ICL implant, FDOCT (RTVue; Optovue Inc) iridocorneal angle measurements were made before and 1 and 3,months after surgery. Trabecular-iris angle (TIA) and angle opening distance 500 mu m anterior to the scleral spur (A0D500) were compared among the quadrants nasal, temporal, and inferior, and correlations with ocular variables including lens vault were examined. RESULTS: Preoperative TIA was 48.7 +/- 8.7, 48.2 +/- 8.7, and 48.7 +/- 9.3 degrees for the nasal, temporal, and inferior quadrants, with no differences (P = 1.000). Following ICL implant, corresponding values fell to 31.2 +/- 11.5, 30.0 +/- 10.7, and 29.7 +/- 8.1 degrees at 1 month postsurgery, indicating angle narrowing of 34%-42%, and to 30.6 +/- 12.3, 30.1 +/- 11.9, and 29.8 +/- 12.3 degrees, respectively, at 3 months postsurgery. Angle measurements failed to vary between 1 month and 3 months postsurgery (P = .481). In 8 eyes, iridotrabecular contact attributable to surgery was observed. One month after surgery, vault measurements correlated with TIA (R = .309; P = .048). Six variables were identified as predictors of TIA at 1 month postsurgery (R-2 = .907). CONCLUSIONS: Although considerable angle narrowing was detected 1 month after ICL V4c implant, this narrowing remained stable at 3 months postsurgery. Factors predictive of TIA could serve to identify suitable candidates for ICL placement. (C) 2016 by Elsevier Inc. All rights reserved.