PURPOSE: To evaluate the factors that affect postoperative astigmatism and post-suture removal astigmatism, and to evaluate the risk factors associated with astigmatism axis shift. METHODS: We performed a retrospective chart review of 130 eyes that had undergone uneventful phacoemulsification cataract surgery. Preoperative astigmatism was divided into four groups (Groups I, II, III, and IV) according to the differences between the axis of preoperative astigmatism (flattest axis) and the incision axis (105 degrees). We analyzed the magnitude and axis of the induced astigmatism after the operation and after suture removal in each group. We also analyzed the factors which affected the postoperative astigmatism and post-suture removal astigmatism in each sub-group of Groups I, II, III, and IV, excluding postoperative or post-suture removal axis shift (specifically, Group I(WAS), II(WAS), III(WAS), and IV(WAS)). We identified the variables associated with the prevalence of postoperative astigmatism axis shift and those associated with the prevalence of post-suture removal axis shift. RESULTS: An increase in the magnitude of postoperative astigmatism was associated with an increase in the preoperative magnitude of astigmatism in Groups I(WAS), II(WAS), and III(WAS) (p<0.05), and with an increase in the corneal tunnel length in Group I(WAS). A decrease in the magnitude of postoperative astigmatism was associated with an increase in the corneal tunnel length in Groups III(WAS) and IV(WAS) (p<0.05). An increase in the magnitude of post-suture removal astigmatism was associated with an increase in the magnitude of postoperative astigmatism in Groups I(WAS) and IV(WAS) (p<0.05), and with late suture removal in Group IV(WAS) (p<0.05). A decrease in the magnitude of post-suture removal astigmatism was associated with late suture removal in Groups I(WAS) and II(WAS). A logistic regression analysis showed that the prevalence of post-suture removal astigmatism axis shift was associated with increased corneal tunnel length, decreased magnitude of postoperative astigmatism, and early suture removal. CONCLUSIONS: In order to reduce postoperative and post-suture removal astigmatism, we recommend a short corneal tunnel length and late suture removal in patients with Group I(WAS) characteristics, late suture removal in Group II(WAS)-like patients, long corneal tunnel length in Group III(WAS)-like patients, and long corneal tunnel length and early suture removal in patients with characteristics of Group IV(WAS).
Astigmatism/etiology/*prevention & control ; Cataract Extraction/*methods ; Follow-Up Studies ; Humans ; Postoperative Complications/etiology/prevention & control ; Retrospective Studies ; *Suture Techniques

The purpose of this study was to compare the effects on astigmatism after penetrating keratoplasty with three different suture techniques. In this prospective study, 38 eyes of 38 patients underwent penetrating keratoplasty with three suturing techniques: interrupted, single running, and double running. Topographic astigmatism was measured at 2, 6, 12, and 18 months after keratoplasty. During 18 months after surgery, the interrupted suture group had higher astigmatism than the double running suture group. There was no significant difference in the amounts of astigmatism during the first year after keratoplasty between the single running and the double running suture group. However, at 18 months after surgery, when all sutures were out, the double running suture group (3.60+/-1.58 diopters) showed significantly less astigmatism than the single running group (5.65+/-1.61 diopters). In conclusion, post-keratoplasty astigmatism was the least in the double running suture group of the three suturing techniques at 18 months after penetrating keratoplasty.
Adult ; Astigmatism/etiology/*prevention & control ; Corneal Diseases/surgery ; Corneal Topography ; Female ; Humans ; *Keratoplasty, Penetrating ; Male ; Middle Aged ; Postoperative Complications ; Prospective Studies ; *Suture Techniques ; Time Factors ; Visual Acuity