Management of postkeratoplasty astigmatism by paired arcuate incisions with compression sutures

摘要

Purpose: To analyse the efficacy of paired arcuate incisions and compression sutures technique in the management of post penetrating keratoplasty (PK) astigmatism. Methods: A paired arcuate incision with compression sutures procedure was used to treat 26 eyes with post- PK astigmatism ranging from 6.00 to 16.50 dioptres (D). The incisions were placed at the 7.0 mm optical zone inside the graft-host junction at a depth of 80% of corneal thickness. A 45?? paired arc length was planned for eyes with preoperative astigmatism between 6D and 9D, and a 60?? paired arc length was planned for eyes with preoperative astigmatism of >9D. At 3 months, corneal topography and refraction was performed and suture(s) removed if indicated. Net and vector astigmatism changes were calculated to determine the efficacy of the procedure. The indications for PK included keratoconus, Fuch's endothelial dystrophy, pseudophakic bullous keratopathy and corneal scar. Results: There was a statistically significant reduction in the mean magnitude of astigmatism from 9.66??2.90D preoperatively to 4.37??2.53D postoperatively in the whole group. The mean decrease in the astigmatism was 4.37??2.05D (58.4%) and 6.23??3.63D (52.6%) in patients with 6-9D and >9D, respectively. Vector power calculations also showed a significant astigmatism reduction in all groups. The safety and efficacy indices were 1.40 and 0.28, respectively. Conclusions: Manual astigmatic keratotomy is a viable technique with relatively good safety and efficacy outcomes. Based on the results we propose that increasing the arc length to a minimum of 60?? for astigmatism of 6-9D, and to 75?? for astigmatism >9D, is likely to have a greater beneficial effect.