Crosslinking for Recurrent Keratoconus

Abstract

About 10% to 15% of keratoconus (KC) patients undergo at least 1 penetrating keratoplasty (PK) in their lifetime; however, recurrent KC is a major complication.1Pramanik S. Musch D.C. Sutphin J.E. Farjo A.A. Extended long-term outcomes of penetrating keratoplasty for keratoconus.Ophthalmology. 2006; 113: 1633-1638Abstract Full Text Full Text PDF PubMed Scopus (162) Google Scholar Corneal collagen cross-linking using riboflavin and ultraviolet A light (CXL) is effective for primary and secondary keractectasia.2Wollensak G. Spoerl E. Seiler T. Riboflavin/ultraviolet-a-induced collagen crosslinking for the treatment of keratoconus.Am J Ophthalmol. 2003; 135: 620-627Abstract Full Text Full Text PDF PubMed Scopus (1913) Google Scholar, 3Hafezi F. Kanellopoulos J. Wiltfang R. Seiler T. Corneal collagen crosslinking with riboflavin and ultraviolet A to treat induced keratectasia after laser in situ keratomileusis.J Cataract Refract Surg. 2007; 3: 2035-2040Abstract Full Text Full Text PDF Scopus (327) Google Scholar To investigate if regrafting could be avoided, CXL was performed in 3 eyes of 3 patients with recurrent progressive KC after PK (Table 1, available at http://aaojournal.org). Recurrent, progressive KC occurred between 17 and 21 years after initial keratoplasty and was defined as an increase of Kmax in corneal topographies of more than 1 diopter over a follow-up of 1 year combined with a decrease in best-corrected visual acuity (BCVA) of at least 1 Snellen line. Anterior corneal curvature, height profile, and BCVA were evaluated before and for at least 12 months after CXL, including corneal topography (Keratograph C, Oculus, Wetzlar, Germany) and Scheimpflug imaging (Pentacam 70700, Oculus, Wetzlar, Germany). Patients using rigid contact lenses removed them at least 1 week before the preoperative examination and before each follow-up examination. The study was approved by the institutional review board of the canton of Zurich and adheres to the tenets of the Declaration of Helsinki. Standard protocol4Seiler T. Hafezi F. Corneal cross-linking-induced stromal demarcation line.Cornea. 2006; 25: 1057-1059Crossref PubMed Scopus (289) Google Scholar CXL using the “epithelium-off method” was performed except that the irradiation area was set for safety at least 1 mm within the limbus and the limbus was protected with a circular wet sponge to protect the limbal stem cells. After the treatment, ofloxacin 0.3% ointment and then a bandage contact lens soaked with preservative-free ofloxacin 0.3% were applied and left until complete healing of the corneal epithelium, followed by fluorometholone 0.1% eye drops twice daily for 2 weeks. Progression of ectasia was arrested in all cases (Fig 1, available at http://aaojournal.org), defined as an increase of less than 1.0 diopter (D) of Kmax for at least 12 months. No operative or postoperative complications were encountered. Recurrent keratoconus after penetrating keratoplasty usually takes up to 2 decades to occur, similar to the time needed for primary keratoconus to evolve.1Pramanik S. Musch D.C. Sutphin J.E. Farjo A.A. Extended long-term outcomes of penetrating keratoplasty for keratoconus.Ophthalmology. 2006; 113: 1633-1638Abstract Full Text Full Text PDF PubMed Scopus (162) Google Scholar This might be explained by the slow migration of abnormal recipient keratocytes into the donor button.5Wollensak G. Green W.R. Analysis of sex-mismatched human corneal transplants by fluorescence in situ hybridization of the sex-chromosomes.Exp Eye Res. 1999; 68: 341-346Crossref PubMed Scopus (59) Google Scholar If this is correct, the recent trend toward deep lamellar keratoplasty might result in an increased incidence of recurrent keratectasia in the future. However, a “limbal” CXL with prophylactic irradiation of the peripheral host cornea before penetrating keratoplasty might be beneficial by destroying peripheral diseased host keratocytes, preventing them from invading the donor cornea thus reducing the incidence of recurrence and possibly also of graft rejection. Prospective trials are needed. This initial study shows that CXL appears to arrest the progression of recurrent ectasia after penetrating keratoplasty for keratoconus with a follow-up of 12 to 19 months. Further studies are needed to confirm this therapeutic effect. F = Female; M = Male; OD = Right eye; OS = Left eye; BCVA = best-corrected visual acuity; CXL = corneal collagen-cross-linking. Extended Long-term Outcomes of Penetrating Keratoplasty for KeratoconusOphthalmologyVol. 113Issue 9PreviewTo report graft survival results for initial penetrating keratoplasty (PK) performed more than 20 years ago for keratoconus. Secondary outcome measures included recurrent keratoconus, best spectacle-corrected visual acuity (BSCVA), and rates of glaucoma. Full-Text PDF