Evaluation Of Angle Of Anterior Chamber After Implantable Collamer Lens Implantation

Purpose:To evaluate the changes of angle of anterior chamber under Implantable Collamer Lens(ICL), to analyze the related factors about the variation.Methods:48eyes of25patients undergoing implantable collamer lens(ICL) at the Eye Center, the2nd Affiliated Hospital of Zhejiang University during May2013to March2014were enrolled. Intraocular pressure was observed pre-operation and post-operation. Anterior Chamber Depth(ACD). Trabecular Iris Angle (TIA)、Angle Opening Distance (AODsoo)、Trabecular Ciliary Process Distance (TCPD). Iris Ciliary Process Distance (ICPD) were measured using ultrasound biomicroscopy (UBM) pre-operation and post-operation. The changes of TIA. AOD500-TCPD. ICPD at the different orientations were compared.The relationships between the changes of TIA. AOD500、TCPD、ICPD and the factors including White To White (WTW)、Sulcus To Sulcus(STS)、corneal curvature were analyzed respectively. Statistical data were analyzed using SPSS19.0software.The difference was considered as significant when P<0.05.Results:There was no statistically significant difference between pre-and postoperative intraocular pressure (IOP)(p=0.131).The mean ACD、TIA、AOD500、 TCPD、ICPD measured by UBM were3.22±0.22mm、57.42±9.31D、0.87±0.35mm、1.60±0.23mm、0.59±0.15mm preoperatively, and2.35±0.34mm、35.30±8.20D、0.36±0.12mm、1.42±0.18mm、0.72±0.14mm postoperatively. There was a statistically significant difference between pre-and postoperative (P<0.01). The TIA、AOD500、 TCPD、ICPD at3:00were59.71±9.24D、0.98±0.38mm、1.67±0.25mm、0.57±0.13mm preoperatively, and38.92±8.50D、0.43±0.14mm、1.46±0.19mm、0.69±0.15mm postoperatively. There was a statistically significant difference (P<0.01). The TIA、 AODsoo、TCPD、ICPD at6:00were55.03±10.19D、0.76±0.34mm、1.52±0.03mm、0.57±0.16mm preoperatively, and31.90±7.08D、0.31±0.09mm.1.40±0.02mm、0.76±0.13mm postoperatively. There was a statistically significant difference (P<0.01). The TIA. AOD500、TCPD、ICPD at9:00were58.05±8.25D、0.87±0.31mm、1.56±0.17mm、0.60±0.17mm preoperatively, and36.71±6.22D、0.37±0.08mm、1.37±0.17mm、0.68±0.14mm postoperatively. There was a statistically significant difference (P<0.01). The TIA、AOD500、TCPD、ICPD at12:00preoperatively were56.88±9.10D、0.86±0.34mm、1.66±0.22mm、0.62±0.15mm, and33.65±8.71D、0.35±0.12mm.1.47±0.18mm.0.76±0.13mm, postoperatively. There was a statistically significant difference (P<0.01). At3:00、6:00、9:00、12:00, There were statistically significant differences among the changes of ICPD, ICPD at6:00changed fewer than that at9:00(P=0.005). There was no statistically significant difference among the changes of TIA、AOD500、TCPD(P>0.05). A negative correlation was found between WTW and the change of the TIA at3:00(P=0.047), and the same as WTW and the change of the TIA at9:00(P=0.001). WTW had no statistically significant correlation with AOD500、TCPD、ICPD at3:00and9:00(P>0.05). Corneal lateral curvature had no statistically significant correlation with TIA、AOD500、TCPD、ICPD at3:00and9:00(P>0.05). A positive correlation was found between STS and the change of the ICPD at9:00(P=0.024).STS had no statistically significant correlation with TIA、AOD500、 TCPD at3:00and9:00, ICPD at3:00(P>0.05).Conclusions:The ACD、TIA、AOD500、TCPD were decreased, ICPD was increased after ICL implantation. The changes of ICPD varied at3:00、6:00、9:00、12:00.The change of ICPD at6:00was smaller than that at9:00. A negative correlation was found between WTW and the change of the TIA at3:00, and the same as that at9:00. A positive correlation was found between STS and the change of the ICPD at9:00. Long time follow-up is still required to observe the change of the anterior chamber angle after ICL implantation.