Stability of Astigmatism Over 3 Years After Corneal Stretch Incision

Abstract

PURPOSE: To assess long-term corneal stability of self-sealing clear corneal stretch incisions with implantation of 5 mm polymethylmethacrylate (PMMA) intraocular lenses. METHODS: Two hundred consecutive eyes of 3500 cataract patients who had capsulorhexis, phacoemulsification, and preparation of a 1.5 to 2.0 mm corneal tunnel that had an external width of 4.0 to 4.1 mm and an internal width of 6.5 to 7.0 nun (stretch incision), and implantation of a 5 mm PMMA intraocular lens were evaluated clinically and statistically. Slit-lamp microscopy, keratometry, and corneal topography were performed preoperatively and postoperatively after 1 week, 1, 2, and 3 years. RESULTS: The mean surgically induced astigmatism following superior corneal incision amounted to 1.59 ± 1.06 D after 3 years; following lateral corneal incision, mean surgically induced astigmatism was 0.84 ± 0.68 D. There were no corneal complications in the long-term follow-up study. CONCLUSION: Our 5-year experience shows that the self-sealing clear corneal stretch incision in connection with implantation of a 5 mm polymethylmethacrylate intraocular lens induces approximately 1.00 D of astigmatism. We prefer the lateral incision and recommend the superior incision only for high preoperative with-the-rule astigmatism. [J Refract Surg 1998;14:455-458]