Effect of Light Conditions and Accommodation on Implantable Phakic Contact Lens Vault by Anterior Segment Optical Coherence Tomography

Abstract

Purpose To investigate the dynamic pupil and vault changes in eyes with implantable phakic contact lens (IPCL) under photopic and scotopic settings, as well as during accommodation using the anterior segment optical coherence tomography (AS-OCT). Methods A prospective observational study included consecutive 36 eyes of myopic patients who underwent IPCL V2.0 implantation. Under photopic and scotopic light settings, as well as during accommodation, all patients were scanned using CASIA OCT (CASIA2; TOMEY, Nagoya, Japan). The pupil size, the vault (distance between the back surface of the IPCL and the anterior lens capsule), ACD-lens (distance between the posterior corneal surface and the anterior lens surface), IPCL-lens (distance between the posterior corneal surface and the anterior IPCL surface), and lens thickness (LT) were the study parameters. Results The vault was significantly lower under photopic conditions ( p -value<0.001). The pupil size was significantly smaller in photopic conditions ( p -value<0.001). LT ( p -value=0.975) and ACD-lens ( p -value=0.917) were not significantly different between scotopic and photopic conditions, while the ACD-IPCL was significantly larger during photopic conditions ( p -value=0.013). There were significant changes in all parameters between accommodative and non-accommodative conditions. Conclusion The IPCL vault decreased significantly under photopic light conditions and accommodation.

Anterior Segment Structure Changes Caused by Different Luminance Light After implantable phakic contact lens Surgery

“…In other words, the change of the light intensity couldn't induce the accomodative response of the crystalline lens. While when the accomodative response occurred, the vault decreased, and the decrease of the vault could be attributed to the backward movement of the ICL and thickness of the crystalline lens 7 .…”

“…When the eye exposed to light, the pupil will constrict. When the PD changes, the vault will change accordingly [5][6][7][8][9] . The safety vault should take into consideration of the change with the light.…”

Anterior segment structure changes caused by different luminance light after implantable collamer lens surgery

“…In other words, the change of the light intensity couldn’t induce the accomodative response of the crystalline lens. While when the accommodative response occurred, the vault decreased, and the decrease of the vault could be attributed to the backward movement of the ICL and thickness of the crystalline lens [ 7 ].…”