Optimization of implantable collamer lens sizing based on swept-source anterior segment optical coherence tomography

Abstract

Purpose: To optimize the implantable collamer lens (ICL) sizing method using anterior segment optical coherence tomography (AS-OCT). Setting: Nagoya Eye Clinic, Nagoya, Japan. Design: Interventional case series. Methods: A stepwise multiple regression analysis was performed using the optimal ICL size as a dependent variable and preoperative AS-OCT parameters as explanatory variables for 81 eyes of 41 patients, and the NK-formula version 2 (NK-formula V2) was obtained. Thereafter, 68 eyes of 42 patients were implanted with the ICLs selected as closest to the optimal ICL size calculated by the NK-formula V2. At 3 months postoperatively, the achieved vault was measured by AS-OCT to evaluate the optimization of the sizing method. Results: The anterior chamber width (ACW) and crystalline lens rise were selected as significant parameters for the regression model (R 2 = 0.61, P < .001), as with the previous NK-formula. Of the 68 eyes, 36 patients/62 eyes (91.2%), 5 patients/5 eyes (7.3%), and 1 patient/1 eye (1.5%) were in the moderate, high, and low vault categories, respectively. In the 68 eyes, the vault showed no correlation with the optimal ICL size (R = 0.0185, P = .269), whereas the vault showed a negative correlation with the optimal ICL size in both the 12.6 mm ICL subgroup (R = −0.409, P = .0088) and the 13.2 mm ICL subgroup (R = −0.818, P = .0013). Conclusions: This optimization approach showed excellent ability to select an appropriate ICL to be implanted regardless of the value of other ocular parameters and age, except ACW.

Development of a Web-Based Ensemble Machine Learning Application to Select the Optimal Size of Posterior Chamber Phakic Intraocular Lens

“… 21 After AS-OCT devices were widely used, the NK formula, which was developed based on ACW and CLR, has been commercially available and widely used for ICL sizing. 22 Researchers have updated the NK formula, 23 however, linear regression has a limitation of explaining the relationships between measurements. In our study, the t-SNE graphs show the nonlinear distribution of the dataset according to the ICL size or vault.…”

Posterior‐chamber phakic implantable collamer lenses with a central port: a review

“…Notwithstanding, although UBM has facilitated the measurement of this distance and it use for vault predictability (Reinstein et al 2013), it is not very widespread in clinical practice, possibly due to its invasiveness and the time required for the measurement. Anterior segment optical coherence tomography has also been used to develop ICL sizing formulas (Nakamura et al 2018; Nakamura et al 2020). WTW distance, which was used in the different studies analysed in this review, seems to provide a useful measure to estimate ICL size and, on average, an adequate vault.…”

​Short-term changes in and preoperative factors affecting vaulting after posterior chamber phakic Implantable Collamer Lens implantation

“…The formula considers the distance between scleral spurs (ACW) and CLR as independent variables, and the R 2 of the multiple regression was 0.68 and the adjusted R 2 was 0.666. In subsequent validation, moderate vault was achieved in 92.1% of cases by the application of the formula [43]. The regression formula in this study has some similarities with the NK formula.…”

“…However, the tting degree of the adjusted R 2 (0.41) was still not completely satisfactory. The NK formula developed by Nakamura et al [34,43] is probably the most accurate prediction formula so far. The formula considers the distance between scleral spurs (ACW) and CLR as independent variables, and the R 2 of the multiple regression was 0.68 and the adjusted R 2 was 0.666.…”