The Changes Of Anterior Segment Characteristics And Lens Density After V4c Icl In Low Anterior Chamber Depth Eyes

To investigate anterior segment and lens density changes after implantable collamer lens V4c (V4c ICL) implantation in eyes with low anterior chamber depth (ACD < 2.8mm) as compared to eyes with normal ACD (ACD > 2.8mm).

Prospective, interventional case-control study.

This study included 96 eyes of 48 patients with a low ACD (<2.8 mm) and 96 eyes of 48 patients with normal ACD (≥2.8 mm). Anterior segment parameters, including ACD, anterior chamber width (ACW), anterior chamber angle (ACA), trabecular-iris angle (TIA), angle opening distance (AOD), trabecular-iris space area (TISA), the distance from cornea to ICL (C-ICL) and vault were all conducted by AS-OCT. The lens density was measured by Pentacam AXL. Linear regression analysis was employed to assess the associations between these parameters and vault. The change of lens density before and after operation was compared between normal ACD eyes and low ACD eyes. All parameters were recorded preoperatively and 1, 3 months and 2 years postoperatively.

The mean safety and efficacy index in low ACD eyes were 1.23±0.22 and 1.21±0.08 respectively. Preoperative ACD and C-ICL demonstrated significant correlations with ICL vault in low ACD eyes (P<0.001). Compared with normal ACD eyes preoperatively, low ACD eyes are more prone to have low vault (P<0.01). There is a correlation between vault and corneal horizontal white-to-white distance (WTW) (P=0.034) and ACD (P=0.048). There was no significant difference in lens density between normal ACD eyes and low ACD eyes (p > 0.05). There was no significant correlation between lens density and vault in low ACD eyes and normal ACD eyes at 2 years after operation (p > 0.05).

The V4c ICL in eyes with low ACD is safe and efficaciou and does not increase lens density. In low ACD patients, the normal vault should be better anticipated by considering preoperative anterior chamber angle, WTW, and ACD.