Assessing the Efficacy of Four Diagnostic Devices and Four Nomograms in Posterior Chamber Phakic Intraocular Lens Size Selection

PURPOSE: To assess the efficacy of different devices and nomograms in predicting the most optimal Implantable Collamer Lens (ICL) (STAAR Surgical) size. METHODS: This retrospective study includes 73 patients (142 eyes) who underwent ICL placement surgery. Anterior segment measurements were obtained by the OPD-Scan III (Marco), the Lenstar LS 900 (Haag-Streit AG/Alcon Laboratories, Inc), the Galilei G4 (Ziemer), and the VuMax ultrasound biomicroscopy device (UBM) (Sonomed Escalon). The efficacy of the four devices and four nomograms was assessed by comparing the indicated ICL sizes to the patient's postoperative vault measurements. RESULTS: Using white-to-white (WTW) measurements obtained by the Lenstar LS 900 and Galilei G4 coupled with the U.S. Food and Drug Administration's (FDA) (also called the manufacturer's) nomogram predicted the highest percentage (33% and 43%) of the 13.7 mm ICL sizes, respectively. Using the VuMax UBM coupled with the Dougherty nomogram indicated the highest percentage (80%) of the 12.6 mm ICL size. The ICL sizes predicted by UBM using the Parkhurst nomogram were comparable to those deemed ideal according to postoperative vault measurements. CONCLUSIONS: The Parkhurst nomogram predicted the most appropriate ICL size. When using WTW measurements, the optimized WTW nomogram showed promising results, especially in eyes whose preoperative calculations suggest low postoperative vaults. Moreover, clinicians should use caution when using the FDA nomogram because it showed a propensity toward indicating oversized ICLs. [ J Refract Surg . 2022;38(2):106–111.]