Effect of the corneal incision direction using an image-guided system on residual astigmatism

Purpose: We evaluated the effect of corneal incision direction using an image-guided system on cataract surgery. Methods: We retrospectively reviewed patients who underwent cataract surgery at The Catholic University of Korea Yeouido St. Mary’s Hospital. The patients were divided into two groups. In group 1 (20 eyes), the corneal incision was made along the steepest axis using the VERION image-guided system (Alcon, Fort Worth, TX, USA). In the control group, group 2 (20 eyes), the incision was made at the vertical or horizontal axis closest to the patient’s steepest axis. We compared residual astigmatism and the mean difference in astigmatism before and after cataract surgery between the two groups using an autorefractor keratometer (RK-F1^®; Canon, Tokyo, Japan) and a Pentacam system (Oculus, Wetzlar, Germany). Results: Group 1’s residual astigmatism was significantly lower than that of group 2 ([VERION group 1; before, 0.89 ± 0.58 D; after, 0.84 ± 0.51 D; p = 0.049] and [control group 2; before, 1.38 ± 0.62 D; after, 1.24 ± 0.62 D; p = 0.043]). The mean difference in astigmatism before and after cataract surgery for group 1 was also larger than group 2 ([VERION group 1; before, 0.71 ± 0.81 D; after, 0.61 ± 0.69 D; p = 0.034] and [control group 2; before, 0.61 ± 0.69 D; after, 0.43 ± 0.61 D; p = 0.048]). Conclusions: Using an image-guided system, postoperative residual astigmatism from cataract surgery can be minimized using an incision direction that is aligned with the corneal astigmatic axis.