AIM: To compare the simulated safe distance (SSD) preoperatively versus real safe distance (RSD) postoperatively in patients with iris-claw phakic intraocular lens (pIOL) implantation according to iris configuration. METHODS: Totally 60 eyes of 60 patients underwent pIOL 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 pIOL shows significant differences in patients with concave and plane iris.