Determining vault size in implantable collamer lenses: preoperative anatomy and lens parameters

Abstract

Purpose: To determine patient preoperative anatomical features and the parameters of implantable collamer lenses (ICLs) relevant in explaining vault variability. Setting: Ophthalmology Clinic Vista Sánchez Trancón, Badajoz, Spain. Design: Retrospective case series. Methods: This study comprised 360 eyes of 360 patients implanted with myopic or toric ICLs. Pentacam imaging was used for assessing white-to-white (WTW) diameter, central keratometry, and central corneal thickness. Anterior-segment optical coherence tomography was used to measure the horizontal anterior chamber angle distance (ATA), internal anterior chamber (ACQ), crystalline lens rise (CLR), anterior chamber angle (ACA), and vault. The sample was divided according to the implanted lens size (12.6 mm, 13.2 mm, and 13.7 mm). Vault predictors were identified from the variables above using multivariate regression analysis. Results: The groups showed significant statistical differences for WTW, ATA, ACQ, ACA, and vault (P < .007 for all). In general, bigger lenses were implanted in eyes with larger transverse sizes (WTW and ATA) and deeper ACQ. Also, larger ICL diameters were associated with higher vaults. Multivariate regression analysis identified the lens size (13.2 mm as reference; 12.6 mm: β [standardized coefficients] = −0.33; 13.7 mm: β = 0.42), ATA (β = −0.42), and CLR (β = −0.25), ICL spherical equivalent (β = −0.22) and patient age (β = −0.12) as predictors of the vault size (adjusted-R 2 = 0.34 P < .001). Conclusions: The multivariate model explained 34% of vault variability. The predictors indicated the presence of different mechanisms regulating the vault. These involved the difference between the transverse size of the eye and the ICL, the crystalline lens protrusion, and the ICL properties, such as power and size.

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

“… 20 Recently, the measurements of ACW, ATA, or CLR using AS-OCT have been used to predict the postoperative vault with the linear regression technique. 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.…”

Biometric and ICL-related risk factors associated to sub-optimal vaults in eyes implanted with implantable collamer lenses

“…To determine the most appropriate ICL size, various studies have sought to predict the vault of an ICL using preoperative parameters [ 7 , 18 – 24 ] showing that the vault is mainly dictated by a relationship between ICL and anatomical factors. Currently, two main principles prevail, one is related to the compression force to which the ICL is exposed due to its larger diameter compared to the transverse size of the eye which produces a forward bulging of the ICL [ 5 , 20 ]; and the other is associated with the space occupied by the crystalline lens on the sagittal depth of the implanted ICL [ 7 , 21 , 25 ].…”

“…Currently, two main principles prevail, one is related to the compression force to which the ICL is exposed due to its larger diameter compared to the transverse size of the eye which produces a forward bulging of the ICL [ 5 , 20 ]; and the other is associated with the space occupied by the crystalline lens on the sagittal depth of the implanted ICL [ 7 , 21 , 25 ]. The vault predictor models described in the literature [ 7 , 18 – 24 ] are based on linear regression analysis assuming a constant relationship between the vault and the independent predictors. However, there is evidence that ICLs implanted with low compression, i.e., small difference between the ICL size and the transverse size of the eye show normal vaults [ 26 ].…”

Correlation between vaulting intraoperative and postoperative of EVO implantable Collamer lens: a retrospective study of real-time observations of vaulting using the RESCAN 700 system

“…Nevertheless, as suggested by Torbey et al [25], the ICL should be exchanged within the same operative session in the presence of extreme vaulting values, improving safety and patient satisfaction. Trancon et al [26] elaborated a multivariable model that could predict vaulting and explain 34% of its variance; lens diameter, horizontal anterior chamber angle distance, CLR, ICL spherical equivalent, and patient age were independently associated with vaulting. In the present study, only the intraoperative vaulting was associated with the value at 1 month.…”

“…Only a few studies examined the use of intraoperative OCT for the determination of ICL vaulting [25]. Of note, a recent multivariable model explains only 34% of the variability of lens vaulting among individuals [26]. Hence, additional studies are necessary to re ne the prediction of ICL vaulting.…”