AIM: To analyze the factors influencing total corneal surgically induced astigmatism(SIA)following implantable collamer lens(ICL)implantation.METHODS:This prospective study enrolled 162 patients(162 eyes)who underwent ICL implantation at our hospital between July 2023 and January 2024. Based on preoperative assessment of anticipated postoperative residual astigmatism, different incisions were selected. Superior incision was selected for patients with expected residual astigmatism with the rule in 75 eyes, and temporal incision was selected for patients with expected residual astigmatism againist the rule in 87 eyes. Parameters including total corneal refractive power, incision length, internal ostium-to-visual axis distance, central corneal thickness, preoperative total corneal astigmatism, and corneal diameter were measured using the Pentacam anterior segment analyzer before and at 3 mo after surgery. Postoperative total corneal SIA was calculated based on the changes in total corneal refractive power. Multiple linear regression analysis was performed to assess the influence of the above parameters on postoperative total corneal SIA.RESULTS:A total of 162 cases(162 eyes)that implanted with ICL were included in the analysis, and 8 cases were lost to follow-up, with a loss rate of 4.9%. Eventually 154 cases(154 eyes)completed the research. The superior incision group comprised 72 cases(72 eyes), including 17 males and 55 females, with a mean age of 25.96±6.17 years, while the temporal incision group comprised 82 cases(82 eyes), including 20 males and 62 females, with a mean age of 27.79±6.47 years. No significant difference in postoperative total corneal SIA was observed between the two groups [0.31(0.21, 0.49)D vs. 0.27(0.13, 0.485)D, P=0.159]. Multiple linear regression analysis revealed that internal ostium-to-visual axis distance and preoperative total corneal astigmatism significantly influenced postoperative total corneal SIA in the superior incision group(P=0.001). The regression equation was: postoperative total corneal SIA=0.71-0.381×internal ostium-to-visual axis distance+0.16×preoperative total corneal astigmatism. No significant influencing factors for postoperative total corneal SIA were identified in the temporal incision group.CONCLUSION: During ICL implantation, the magnitude of total corneal SIA is comparable between superior and temporal incisions. For patients receiving a superior incision, the internal ostium-to-visual axis distance and preoperative total corneal astigmatism value can be used to quantitatively predict postoperative total corneal SIA to a certain extent, thereby aiding in the optimization of postoperative visual quality.