The Comparison of Induced Astigmatism and Clinical Results after Cataract Surgery using Different Clear Corneal Incisions

ABSTRACT

PURPOSE: To compare the induced astigmatism and clinical results after cataract surgery using different clear corneal incisions. METHODS: This prospective, nonrandomized study comprised 60 eyes (48 patients) scheduled for cataract surgery between October 2000 and March 2001; 20 eyes received 1-plane stab clear corneal incisions(Group 1), 20 eyes, 2-plane stab clear corneal incisions(Group 2) and 20 eyes, 2-plane hinge incisions(Group 3). Preoperative corneal astigmatism, surgically induced corneal astigmatism and changes of visual acuity were analyzed at 1 day, 1 and 2 weeks, 1 and 2 months postoperatively using ARK-700(NIDEK) and visual acuity chart projector. Data and group comparisons were evaluated by ANOVA, Chi-Square test, Repeated measures ANOVA, Kruskal-Wallis test, Analysis of CoVariance(ANCOVA). RESULTS: The surgically induced astigmatism in all groups showed no difference in WTR change and uncorrected visual acuity also showed no different results in all groups. Mean keratometric astigmatisms were 0.23+/-1.05 D (ATR) preoperatively, 0.03+/-1.31 D (WTR) at 1 day, 0.14+/-1.13 D at 1 week, 0.16+/-1.11 D at 2 weeks, 0.13+/-1.07 D at 1 month, 0.11+/-1.04 D (WTR) at 2 months. Mean surgically induced keratometric astigmatisms were 0.75+/-0.65 at 1 day, 0.65+/-0.43 D at 1 week, 0.54+/-0.48 D at 2 weeks, 0.53+/-0.45 D at 1 month and 0.45+/-0.46D (WTR) at 2 months after operation. CONCLUSIONS: There were no significant differences in postoperative visual acuity and surgically induced astigmatism at 2 months postoperatively among these three groups and all incisions offered satisfactory short-term astigmatic results and rapid visual rehabilitation. A longer study of a larger series should be done to confirm the findings.