M Tehrani1, O Schwenn, H B Dick. 1. John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA. Tehrani@augen.klinik.uni-mainz.de
Abstract
BACKGROUND: After penetrating keratoplasty residual astigmatism can be treated with various options. Correction with spectacles or contact lenses, methods such as radial keratotomy, photorefractive keratectomy (PRK) or Laser-in-situ keratomileusis (LASIK) are limited only to mild and moderate astigmatism. In laser ablation a sufficient corneal thickness must be ensured. On the other hand surgical correction is performed on transplanted tissue which can increase the risk of allograft rejection. In pseudophakic eyes the implantation of an individually designed toric intraocular lens (IOL) according to keratometry and biometry with a cylindrical power up to 12 D provides an alternative method for correcting higher astigmatism. This individually designed IOL can be implanted additionally to the existing IOL. CASE: A 66-year-old patient presented after penetrating keratoplasty and implantation of an IOL 4 years ago with a visual acuity of 20/160 and residual astigmatism of - 10 D x 151(o). After biometry an individually manufactured toric PMMA-IOL of + 12 D cylindrical and - 9.5 D spherical power was implanted via a sclerocorneal tunnel incision additionally to the existing IOL into the ciliary sulcus. Postoperatively a well centered and stable positioned IOL was found. One year after implantation of the toric IOL the position was still unchanged and the graft had remained clear. Spherical equivalent refraction was + 1,5 D - 3,0 D x 141(o), with an uncorrected visual acuity of 20/60. CONCLUSION: Implantation of a toric intraocular lens in pseudophakic eyes allows the correction of high astigmatism after penetrating keratoplasty. The advantage of this method compared to the keratorefractive options lies in its minor manipulation on the allograft.
BACKGROUND: After penetrating keratoplasty residual astigmatism can be treated with various options. Correction with spectacles or contact lenses, methods such as radial keratotomy, photorefractive keratectomy (PRK) or Laser-in-situ keratomileusis (LASIK) are limited only to mild and moderate astigmatism. In laser ablation a sufficient corneal thickness must be ensured. On the other hand surgical correction is performed on transplanted tissue which can increase the risk of allograft rejection. In pseudophakic eyes the implantation of an individually designed toric intraocular lens (IOL) according to keratometry and biometry with a cylindrical power up to 12 D provides an alternative method for correcting higher astigmatism. This individually designed IOL can be implanted additionally to the existing IOL. CASE: A 66-year-old patient presented after penetrating keratoplasty and implantation of an IOL 4 years ago with a visual acuity of 20/160 and residual astigmatism of - 10 D x 151(o). After biometry an individually manufactured toric PMMA-IOL of + 12 D cylindrical and - 9.5 D spherical power was implanted via a sclerocorneal tunnel incision additionally to the existing IOL into the ciliary sulcus. Postoperatively a well centered and stable positioned IOL was found. One year after implantation of the toric IOL the position was still unchanged and the graft had remained clear. Spherical equivalent refraction was + 1,5 D - 3,0 D x 141(o), with an uncorrected visual acuity of 20/60. CONCLUSION: Implantation of a toric intraocular lens in pseudophakic eyes allows the correction of high astigmatism after penetrating keratoplasty. The advantage of this method compared to the keratorefractive options lies in its minor manipulation on the allograft.