Comparison of surgically induced astigmatism after sutureless temporal clear corneal and scleral frown incisions.

摘要

PURPOSE: To compare the corneal astigmatic changes induced by clear corneal 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 Kung University, Tainan, Taiwan, Republic of China. METHODS: This prospective study comprised 120 eyes divided into two groups of 60 each based on incision type. All patients had examinations with an autokeratometer preoperatively and 1 week and 1, 3, and 6 months postoperatively. RESULTS: Simple subtraction of the scalar analysis in each group showed minimal astigmatic changes; however, the standard deviation of astigmatic 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 and 1, 3, and 6 months, respectively. In the clear corneal incision group, it was 1.55, 1.12, 0.93, and 0.92 D at the same intervals. In the scleral frown incision group, Naeser's polar value also showed minimal changes in polar astigmatism throughout the study; in the clear corneal incision group, it showed a mean with-the-rule (WTR) astigmatic shift 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 minimal astigmatic change 1 week after scleral frown incisions, while clear corneal incisions induced greater WTR astigmatism with delayed stabilization 1 to 3 months postoperatively.