Peripheral Anterior Chamber Depth and Angle Measurements Using Pentacam After Implantation of Toric and Non-toric Implantable Collamer Lenses.

Jiao Zhao,Xingtao Zhou,Wen Yang,Jing Zhao,Jianmin Shang,Xiaoying Wang,Huamao Miao,Lingling Niu

doi:10.3389/fmed.2021.610590

Abstract

Purpose: To evaluate the characteristics of peripheral anterior chamber measurements by Pentacam after posterior implantable collamer lenses (ICL) and toric ICL (TICL) with central hole (V4c) implantation.Methods: Prospective, non-randomized consecutive case series. Forty-six patients undergoing ICL implantation in one eye (Group A) and identically sized TICL in the contralateral eye (Group B) in the Refractive Surgery Center of Eye and ENT Hospital of Fudan University were prospectively included. According to ICL/TICL size, these eyes were further divided into four subgroups. Peripheral anterior chamber depth (PACD) and angle (ACA) in nasal and temporal sides were measured using Pentacam pre-operatively and 12-month post-operatively.Results: The safety indices were 1.34 ± 0.32 and 1.25 ± 0.16 and the efficacy indices were 1.20 ± 0.24 and 1.19 ± 0.19 for ICL and TICL groups, respectively. There was no significant difference in pre-operative PACD or ACA between the two groups. Post-operative PACD and ACA were significantly lower than pre-operative values. Variations of PACD and ACA of TICL group were significantly larger than those of ICL group. The change of ACA for 13.2 mm lenses was significantly larger than that of 12.6 mm lenses. Pre-operative CACD and vault were significantly associated with post-operative PACD, while pre-operative ACA and vault were significantly associated with post-operative ACA.Conclusions: Variations of PACD and ACA were greater in eyes after TICL (V4c) implantation compared with identically sized ICL (V4c) implantation and with larger size than smaller size lens implantation. Pre-operative anterior chamber structure and vault affect post-operative PACD and ACA.

Highlights

Implantation of the implantable collamer lens (ICL)/ toric ICL (TICL) (V4c) with a central port is preferred over corneal refractive surgery by refractive surgeons and patients for its reversibility and excellent visual quality [1,2,3]
anterior chamber angle (ACA) is the key anatomic parameter determining the risk for primary angle closure glaucoma (PACG) [5]
Shallow anterior chamber depth (ACD) or narrow ACA leads to the possibility of angle closure glaucoma (ACG) and extraction of the ICL/TICL [9, 10]

Summary

Introduction

Implantation of the implantable collamer lens (ICL)/ toric ICL (TICL) (V4c) with a central port is preferred over corneal refractive surgery by refractive surgeons and patients for its reversibility and excellent visual quality [1,2,3]. ICL is positioned in the ciliary sulcus and protrudes forward to form a vault, resulting in post-operative narrowing of the anterior chamber angle (ACA) width and decreasing the central anterior chamber depth (CACD) [4]. In addition to ACA, peripheral anterior chamber depth (PACD) shows good sensitivity for detecting eyes at risk for angle closure [8]. Shallow anterior chamber depth (ACD) or narrow ACA leads to the possibility of angle closure glaucoma (ACG) and extraction of the ICL/TICL [9, 10]. For these reasons, prediction and monitoring of post-operative ACA and PACD in the long term are essential to improve the safety of ICL/TICL (V4c) implantation

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Results

Conclusion