Inter-eye vault differences in bilaterally implanted patients with implantable collamer lenses

Session Details

Session Title: Presented Poster Session: Intraocular Refractive Surgery

Venue: Poster Village: Pod 2

First Author: : J.Cerpa Manito SPAIN

Co Author(s): :    P. Serra   Á. Sánchez Trancón   O. Torrado   A. Baptista              

Abstract Details

Purpose:

The distance between an Implantable Collamer Lens (ICL) and the crystalline lens, namely the vault, is a dynamic space influenced by the interaction of the ICL with the anatomical structures of the eye. When implanted bilaterally ICLs tend to show similar vaults but rarely of the same value, also some patients may present differences of questionable clinical significance. Knowing the range of differences observed in the standard vault assessment between fellow eyes implanted with similar ICL will inform about the floor variability in vault size. This study aims to analyze the range of differences in vault sizes between fellow eyes.

Setting:

Ophthalmology Clinic Vista Sánchez Trancón, Badajoz, Spain

Methods:

This retrospective case series analyzed 109 cases of patients bilaterally implanted with spherical or toric myopic ICL (EVO-V4c, STAAR Surgical Co. Monrovia, CA, USA). Patients included in the analysis had minimal anatomical inter-eye preoperative differences assessed by the anterior-segment optical coherence tomographer AS-OCT Visante (Carl-Zeiss Meditec, Jena, Germany), the same type of ICL and ICL power differences smaller than 1.00DS. Bilateral static vault assessments were performed three-to-six months postoperatively using the AS-OCT Visante. Inter-eye vault differences range was defined as the 95% confidence interval (CI) of the differences. Multivariate regression was applied to find predictors of inter-eye vault differences.

Results:

Fellow eyes vaults were significantly correlated R-square =0.82, p<0.001. The mean inter-eye vault differences showed did not differ from zero (26.0 ± 122.5µm) and the 95% CI range of the differences equaled to ±240.1µm. Multivariate regression analysis identified the average vault size as a predictor of the inter-eye vault differences R-squared=0.094, p=0.001. The mean inter-eye vault differences increased with the vault magnitude, 30µm (<250µm), 60 µm ([250; 750]µm) and 140 µm (>75µm). Considering the total group, 31% of the patients had inter-eye differences smaller than 40 µm, 54% smaller than 100µm and 78% below 160µm.

Conclusions:

Fellow eyes implanted with similar ICL tend to exhibit similar vaults. The inter-eye differences, however, can spread up to 240µm and the difference increases with the vault magnitude. The variability found in this group of patients may reflect the dynamic nature of the vault captured in a static manner and the resting position of the ICL within the eye. As a practical output, the 240 µm value can be considered as a threshold value for the presence of clinical different vaults and may serve as an estimator of the vault value in the second eye surgery.

Financial Disclosure:

... is employed by a for-profit company with an interest in the subject of the presentation