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

Abstract

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.]

Evaluation of biometric indicators of anterior segment parameters after ICL implantation by swept-source optical coherence tomography

“…Moreover, ophthalmologists usually use the STAAR manufacturer’s online calculator to determine ICL size. This method is based on the preoperative WTW and ACD of the patient, and the indicated ICL size is generally too large, resulting in a high proportion of patients with an excessive postoperative vault [ 30 ]. Therefore, more attention should be paid to angle narrowing and suspicious angle-closure caused by an abnormal vault after ICL implantation.…”

Predictability of the vault after implantable collamer lens implantation using OCT and artificial intelligence in White patient eyes

“…Consistently with previous studies, STAAR's nomogram was found to indicate ICL sizes larger than the ideal size, potentially leading to oversizing complications, such as angle-closure glaucoma. 26,27 The accuracy of ET and RF models in predicting the vaulting value, with a precision of ±250 μm, was 94% and 90%, respectively. By developing classifiers, this accuracy improved to an excellent value of 98%, which was possible as the classifiers predict a discrete output (ICL size), rather than a continuous output (vault size), with a lower dependence on nondeterministic parameters.…”

Improvement in the ideal range of vault after implantable collamer lens implantation: a new vault prediction formula

“…Rancons ( 6 ) and Zhang ( 16 ) used WTW and ACD to select the lens size based on the STAAR formula, and 53 and 65%, respectively, of the subjects achieved postoperative vault in the ideal range. Moshirfar ( 17 ) used STS and lens rise to select the lens size, and 77% patients achieved the ideal vault. Malyugin ( 18 ) used PTP (iris pigment end to iris pigment end distance) for size selection, and 55% of the patients achieved the ideal vault after surgery.…”