Comparison of surgically induced astigmatism between horizontal and X-pattern sutures in the scleral tunnel incisions for manual small incision cataract surgery

BACKGROUND: Two types of popular scleral tunnel sutures in the manual small incision cataract surgery (MSICS) are horizontal and X-pattern sutures. Surgically induced corneal astigmatism (SIA) is a useful indicator of the suturing effect. AIMS: To compare SIA between horizontal and X-pattern sutures in the scleral tunnel incisions for MSICS. DESIGN: Prospective, nonrandomized comparative trial. MATERIALS AND METHODS: After superior scleral tunnel incision and capsulorhexis, the nucleus was prolapsed into the anterior chamber and delivered. The wound was sutured with either horizontal or X-pattern suture. The simulated keratometry values were derived from the corneal topography preoperatively and 1.5 and 3 months postoperatively. STATISTICAL ANALYSIS: The SIA was calculated by Cartesian coordinates based analysis. RESULTS: Sixty-four patients (32 patients in each group) were included in the study. In the horizontal suture group, the SIA centroid values at 1.5 and 3 months after the surgery were 0.87 × 1° and 1.11 × 180°, respectively, showing induction of against-the-rule astigmatism. In the X-pattern suture group, the SIA centroid values at 1.5 and 3 months after the surgery were 0.61 × 97° and 0.66 × 92°, respectively, showing induction of mild with-the-rule astigmatism. The difference between the amount of SIA at 1.5 and 3 months after surgery was small. CONCLUSION: In the MSICS, the X-pattern sutures were preferred to the horizontal sutures in the patients without significant preoperative steepening in line with the central meridian of the incision. In the cases with significant preoperative steepening, sutureless surgery or horizontal sutures were preferred. Corneal astigmatism in the patients undergoing MSICS was stable at 1.5 months after the surgery.