Effect of a standard paired arcuate incision and augmentation sutures on postkeratoplasty astigmatism

Purpose: To analyze the efficacy of a standardized paired arcuate incision and augmentation suture technique in the treatment of various levels of pos t-penetrating keratoplasty (PKP) astigmatism. Setting: Lions Eye Institute, Royal Perth Hospital, Perth, Australia, and U niversity of Dundee Department of Ophthalmology, Dundee, United Kingdom. Methods: A standardized paired arcuate incision and paired augmentation sut ure technique was used to treat 34 eyes with post-PKP astigmatism ranging f rom -3.50 to -20.00 diopters (D) at the spectacle plane. The technique cons isted of paired arcuate incisions of 3 clock hours, 480 mu m deep in the gr aft-host junction, and 2 pairs of augmentation 10-0 nylon sutures. Results: The mean preoperative cylinder was -9.14 D +/- 4.38 (SD) and the m ean post operative cylinder, -3.59 +/- 1.92 D at the corneal plane after a mean follow-up of 50 +/- 43 weeks. This represents an empirical reduction i n mean cylinder of 5.55 D (60.7%). The Alpins correction index (surgically induced astigmatism [SIA] divided by target i induced astigmatism) was calc ulated for each case, and the mean was 1.01 +/- 0.34, with a median of 0.91 , Approximately 53.1% of cases achieved a correction index between 0.80 and 1.20, and the correction index correlated poorly with the initial magnitud e of cylinder. A direct numerical relationship between SIA and the initial magnitude of cylinder was observed, although a standard surgical procedure was used in ail cases. Conclusion: A simple standardized technique using paired arcuate incisions in the graft- host junction with paired augmentation sutures reduces the am ount ol cylinder in proportion to the magnitude of the preoperative cylinde r and effectively reduces post-PKP astigmatism. J Cataract Refract Surg 200 0; 26:553-561 (C) 2000 ASCRS and ESCRS.