A Comparative Study of Surgically Induced Astigmatism From Temporal and Steep-Axis Clear Corneal Incisions in...

Background Surgically induced astigmatism (SIA) is a critical determinant of visual outcomes after phacoemulsification cataract surgery. The choice of incision site significantly influences postoperative refractive stability. This study compares temporal clear corneal incision (CCI) and steep-axis CCI in terms of SIA, uncorrected visual acuity (UCVA), and corneal stability. Methods This prospective randomized study included 130 patients with senile cataract and preoperative corneal astigmatism ≤1.5 D (diopters), allocated into two groups: Group A (temporal incision, n = 65) and Group B (steep-axis incision, n = 65). All surgeries were performed by a single surgeon using standardized phacoemulsification techniques. Preoperative and postoperative assessments included UCVA, best-corrected visual acuity (BCVA), corneal astigmatism, and SIA calculated using vector analysis (magnitude only). Follow-up was performed at day 1, day 7, and one month. Data were analyzed using independent t-tests and chi-square tests, with p < 0.05 considered significant. Results Baseline characteristics were comparable, though a minor imbalance in preoperative astigmatism was noted. At one month, UCVA was significantly better in the temporal group (p = 0.020), while BCVA showed no intergroup difference. Median SIA was lower with temporal incisions (p = 0.003). Corneal astigmatism was also reduced in Group A at day 7 (p < 0.001) and one month (p < 0.001). At one month, 93.8% of patients in Group A achieved corneal astigmatism ≤0.5 D versus 61.5% in Group B (p < 0.001). No significant differences were observed in with-the-rule (WTR) or against-the-rule (ATR) astigmatism patterns. Conclusion Temporal CCI induced less astigmatism and provided better early visual outcomes compared with steep-axis CCI. While these results support the temporal approach for optimizing refractive outcomes in cataract surgery, interpretation should be cautious given the short follow-up, lack of masking, and limited reporting of vector direction. Larger, long-term studies are warranted to validate these findings.