Comparison of preoperative simulated and postoperative real safety distances using anterior segment OCT in patients with phakic IOL according to iris configuration

AIM:To compare the simulated safe distance(SSD)preoperatively versus real safe distance(RSD)postoperatively in patients with iris-claw phakic intraocular lens(p IOL)implantation according to iris configuration.METHODS:Totally 60 eyes of 60 patients underwent p IOL implantation for surgical correction of myopia.Anterior chamber depth(ACD)was measured with the IOLMaster 700,and nasal and temporal safety distances(SD)were measured pre-and postoperatively using Anterior Segment Visante-OCT.SD was defined as a line measured between the edge of the optic or its simulated image to the endothelium.Eyes were divided into 3 groups:convex,concave,and plane according to preoperatory iris configuration.Statistical analysis was performed using the R program,for the comparison of independent groups and multiple comparisons,the Kruskal-Wallis test and the Dunn test were used respectively.RESULTS:Mean difference between nasal preoperative SSD and postoperative RSD was-0.36±0.38,-0.29±0.48,and-0.18±0.30 mm in the concave,convex,and plane group,respectively.Mean difference between temporal SSD and RSD was-0.36±0.37,-0.14±0.38,and-0.24±0.33 mm in the concave,convex,and plane group,respectively.There were statistically significant differences between SSD and RSS for both nasal and temporal sides in the concave and plane group(P<0.002).CONCLUSION:Preoperative SSD and postoperative RSD for iris-claw p IOL shows significant differences in patients with concave and plane iris.