AIM: To study the early outcomes of anterior segment parameters after implantation of an implantable collamer lens with a central hole(ICL V4c)in patients with high myopia.

METHODS:A total of 82 cases(160 eyes)with high myopia, including 42 males(82 eyes)and 40 females(78 eyes), aged 26.0±4.6(21 to 37)years, who underwent ICL V4c implantation at our institution from February 2019 to September 2022 and were followed up for 1 a, were included. The general characteristics of the anterior segment of the eye were measured preoperatively: spherical equivalent, mean horizontal corneal curvature, white-to-white(WTW), and axial length(AL); intraocular pressure(IOP), endothelial cell density(ECD), central anterior chamber depth(CACD), anterior chamber volume(ACV)and anterior chamber angle(ACA)were measured preoperatively and at 1 d, 1 wk, 1, 3 and 6 mo postoperatively. Furthermore, the distance from the centre of the posterior surface of the ICL V4c optical zone to the anterior surface of the lens(vault)was measured at 1 d, 1 wk, 1, 6 mo, and 1 a after surgery.

RESULTS: The mean preoperative spherical equivalent of the patients was -7.56±2.55 D, mean horizontal corneal curvature was 42.89±1.47 D, WTW was 11.64±0.37 mm, and AL was 26.64±0.93 mm. The baseline IOP was 15.97±2.13 mmHg, and the differences in IOP at each time point after ICL V4c implantation compared to preoperative were not statistically significant(F=0.875, P=0.504); ECD was 2 989.30±140.78 cells/mm² at baseline, and ECD at 6 mo after ICL V4c implantation was not statistically significant compared with preoperative ECD(t=1.475, P=0.142); CACD was 3.19±0.21 mm at baseline, and ACV was 210.30±27.7 mm³, and CACD and ACV were significantly lower than preoperative at all postoperative time points(F=111.10, 288.38, all P<0.001). The baseline ACA was 35.44°±11.27°, and the ACA at each time point after ICL V4c implantation was significantly lower than preoperatively(F=21.23, P<0.001). The vault was 665.32±184.03 μm at 1 d postoperatively, and continued to be significantly reduced at 1 wk, 1, 6 mo, and 1 a postoperatively compared with 1 d(F=52.10, P<0.001). However, it remained stable at 6 mo and 1 a postoperatively, and the difference was not statistically significant compared with vault at 1 mo postoperatively(P>0.05).

CONCLUSION: ICL V4c has certain safety and efficiency in 1 a postoperative follow-up, and the parameters of the anterior segment of the eye stabilized in the early period.