Comparison of Surgically Induced Astigmatisms after Clear Corneal Incisions of Different Sizes

Purpose: This study was performed to assess efficiency and stability of astigmatic change by incision size after cataract surgery. Methods: This work was designed as a retrospective, comparative, nonrandomized interventional study. A total of 121 cases of cataract surgery were reviewed in 98 patients performed by one surgeon at the Oregon Eye Institute in Eugene, OR, USA with 3-year follow-ups. All procedures were performed with the temporal approach of self-sealing incisions. The serial change in surgically induced astigmatisms were examined in all cases of three groups: Group A, cartridge injection of a foldable IOL through a 2.5 mm self-sealing incision; Group B, cartridge injection of a foldable IOL through a 3.0 mm self-sealing incision; Group C, cartridge injection of a foldable IOL through a 3.5 mm self-sealing incision. Keratometric data were obtained preoperatively, and 3 weeks, 3 months, 6 months, 9 months, 12 months, 24 months and 36 months postoperatively. Polar value analysis was performed to calculate the surgically induced astigmatism. Results: The astigmatic change decreased over time in Group B (P<0.05). The other groups tended to remain in induced astigmatism. All groups showed anticlockwise torque at 3 weeks following surgery. Group B showed a decrease in deviation, but the other groups showed increases in their torque value at postoperative 12 months (P<0.05). Conclusions: The 3.0 mm incision size correlated with the least surgically induced astigmatism.