One-year natural course of corneal densitometry in high myopic patients after implantation of an implantable collamer lens (model V4c)

Abstract

Background: Corneal densitometry, which is also known as corneal backscattering, is a surrogate measure of corneal clarity. The purpose of the study was to investigate the changes in corneal densitometry (CD) after implanting an implantable collamer lens (ICL-V4c). Method: Twenty-six high myopic patients (aged 29.3 ± 6.6 years, 6 males and 20 females) who underwent ICL-V4c implantation were enrolled. Intraocular pressure (IOP), corneal topography, corneal densitometry, uncorrected distance visual acuity (UCDVA), manifest refraction, and best corrected distance visual acuity (BCDVA) were evaluated preoperatively and at 1 day, 1 week, and 1, 3, 6, and 12 months post-operatively. Endothelial cell density (ECD) was measured pre-operatively and at 3, 6, and 12 months post-operatively. The efficacy index (mean post-operative UCDVA / mean pre-operative BCDVA) and the safety index (mean post-operative BCDVA / mean pre-operative BCDVA) were evaluated at 1 month, 3 months, 6 months and 12 months post-operatively. Results: Over the annular diameters of 0-2 mm, the pre-operative densitometry values of the anterior layer, central layer, posterior layer, and total layer were 20.1 ± 2.8, 11.8 ± 1.1, 10.5 ± 0.9 and 14.1 ± 1.5, respectively. From pre-operatively to post-operative Month 12, the values changed insignificantly (P = 0.177, P = 0.153, P = 0.543 and P = 0.207, respectively). Over the annular diameters of 2-6 mm, the pre-operative mean densitometry values were 17.9 ± 2.2, 10.5 ± 0.9, and 12.6 ± 1.2, respectively. From pre-operatively to post-operative Month 12, the values decreased to 16.5 ± 2.1, 10.0 ± 0.9, and 11.9 ± 1.2, respectively, which were similar to the pre-operative values (all P > 0.05) but significantly lower than the values obtained at post-operative Day 1 (P = 0.013, P = 0.002 and P = 0.010, respectively). The densitometry value of the posterior layer over the annular diameters of 2 to 6 mm remained unchanged (from 9.4 ± 0.7 to 9.1 ± 0.7) over time (P = 0.372). The efficacy and safety indices assessed at 12 months post-operatively were 1.04 ± 0.27 and 1.19 ± 0.23, respectively. The changes in IOP and ECD values were statistically insignificant (P = 0.896 and P = 0.968, respectively). Conclusion: ICL-V4c implantation may be safe and efficient for high ametropia correction. The corneal densitometry values obtained over the annulus of 0-6 mm increased slightly from before the operation to post-operative Day 1 and then decreased gradually, which indicates that ICL-V4c implantation may not compromise corneal clarity.

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

“…They were published between 2012 and 2020. Table 1 presents a summary of these 35 clinical studies reporting data on the V4c ICL (Shimizu et al 2012; Alfonso et al 2013; Lisa et al 2015; Karandikar et al 2015; Shimizu et al.2016; Bhandari et al 2016; Eissa et al 2016; Chen et al 2016; Cao et al 2016a; Cao et al 2016b; Goukon et al 2017; Ganesh et al 2017; Rodríguez‐Una et al 2017; Pjano et al 2017; Kamiya et al 2017; Totsuka et al 2017; Fernández‐Vigo et al 2017; Kamiya et al 2018; Garcia‐de la Rosa et al, 2018; Fernández‐Vega‐Cueto et al 2018; Yan et al 2018; Kojima et al.2018; Li et al 2018; Takahashi et al 2018; Lee et al 2018a,b; Alfonso et al 2019; Rizk et al 2019; Zhu et al 2019; Niu et al 2019; Sachdev et al 2019; Martínez‐Plaza et al 2019; Wan et al 2019; Niu et al 2020; Chen et al 2020): authors, maximum follow‐up, number of eyes and patients included, sample mean age, preoperative SE, WTW, ACD, K, CCT and ICL size and power are shown. The outcomes of the 2904 eyes implanted with the V4c ICL model are described and analysed in these studies.…”

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

“…We found that the ICL size, followed by horizontal STS, crystalline LT and vertical STS, significantly influenced 1-month postoperative vaulting. Previous studies have shown that the ciliary sulcus is vertically oval [ 37 – 39 ]. Because the ICL has a flat plate design and a certain width, the supporting points of the lens are located between the horizontal and vertical ciliary sulcus but closer to the horizontal position.…”

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

“…We found that ICL size, followed by horizontal STS, crystalline LT and vertical STS, signi cantly in uenced 1-month postoperative vaulting. Previous studies have shown that the ciliary sulcus is vertically oval [37][38][39].…”