COMPARISON OF SURGICALLY INDUCED ASTIGMATISM AFTER SUTURELESS TEMPORAL CLEAR CORNEAL AND SCLERAL FROWN INCISIONS

Purpose: To compare the corneal astigmatic changes induced by clear co rneal incisions with those induced by scleral tunnel frown incisions, both from a temporal approach, in sutureless cataract surgery. Setting : Department of Ophthalmology, College of Medicine, National Cheng Kun g University, Tainan, Taiwan, Republic oi China. Methods: This prospec tive study comprised 120 eyes divided into two groups of 60 each based on incision type. All patients had examinations with an autokeratomet er preoperatively and 1 week and 1, 3, and 6 months postoperatively. R esults: Simple subtraction of the scaiar analysis in each group showed minimal astigmatic changes; however, the standard deviation of astigm atic change was greater in the clear corneal incision group. The mean vector analysis of surgically induced astigmatism in the scleral frown incision group was 0.69, 0.75, 0.72, and 0.61 diopter (D) at 1 week a nd 1, 3, and 6 months. respectively In the clear corneal incision grou p, it was 1.55, 1.12, 0.93, and 0.92 D at the same intervals. In the s cleral frown incision group, Naeser's polar value also showed minimal changes in polar astigmatism throughout the study; in the clear cornea l incision group, it showed a mean with-the-rule (WTR) astigmatic shif t of +0.73, +0.22, +0.13, and +0.08 D at 1 week and 1, 3, and 6 months . respectively. Conclusion: Corneal stability was achieved with minima l astigmatic change 1 week after scleral frown incisios, while clear c orneal incisions induced greater WTR astigmatism with delayed stabiliz ation 1 to 3 months postoperatively.