Abstract:

Objective To compare the difference of anterior chamber angle of high myopia patients who received V4 or V4c implantable collamer lens (ICL) implantation. Design Retrospective case series. Participants 60 patients (60 eyes) with high myopia who received V4 or V4c ICL implantation and Visante anterior segment OCT examination 3 months postoperation in Beijing Tongren Hospital from February 2014 to September 2015. Methods The intraocular pressure (IOP), spherical equivalent, spur to spur distance, central anterior chamber depth, angle data preoperation and IOP, corneal endothelium to ICL distance, vault and angle data postoperation were retrospectively analyzed. The preoperative and postoperative angle data and the anterior segment data were compared between V4 group and V4c group. Main Outcome Measures IOP and angle data, including 500 μm and 750 μm angle open distance (AOD), 500 μm and 750 μm trabecular-iris space area (TISA) and scleral spur angle (SSA). Results There was no significant difference between the two groups in terms of IOP, spherical equivalent, spur to spur distance, central anterior chamber depth and angle data preoperatively (P＞0.05). The IOP, corneal endothelium to ICL distance, vault and angle data were not statistically different between the two groups postoperatively (P＞0.05). In V4 group and V4c group, postoperative anterior chamber angle was significantly narrowed  (P＜0.01), and SSA decreased by 43%~47% and 39%~40% respectively compared to the preoperation. Conclusion After V4 and V4c ICL implantation, the anterior chamber angle was significantly narrowed, and the angle parameters were similar between the two groups. Because of the prophylactic iridotomy of V4 and the central hole design of V4c, no significant IOP elevation was observed after ICL implantation.

Key words: implantable collamer lens, high myopia, angle open distance, trabecular-iris space area, scleral spur angle