title: A case of in vivo iontophoresis-assisted corneal collagen cross-linking for keratoconus: An immunohistochemical study.
abstract: The standard corneal collagen cross-linking (CXL), that includes the removal of corneal epithelium to permit adequate penetration of riboflavin in the stroma, is an established procedure to halting keratoconus progression. However, as epithelial removal may cause postoperative pain and an increased risk of corneal infection, new therapeutic approaches have been proposed. Iontophoresis is a recently developed non-invasive technique which provides the use of electrical current during CXL to enhance transepithelial penetration of riboflavin into the corneal stroma. Here, we describe for the first time the morphological changes of the corneal stromal compartment in a patient with keratoconus who underwent in vivo iontophoresis-assisted CXL (ionto-CXL) before full-thickness corneal transplantation. Immunohistochemistry for type I collagen and CD34 was performed to investigate the stromal distribution of collagen fibers and keratocytes, respectively. The histology of ionto-CXL-treated keratoconic cornea, collected 6 months after the intervention, was compared with that of healthy corneas and either untreated or standard CXL-treated keratoconic corneas. An attempt to restore a normal stromal architecture was observed in the ionto-CXL-treated cornea compared with untreated keratoconic corneas. In particular, the ionto-CXL-treated cornea showed a parallel distribution of type I collagen fibers, although fiber interweaving appeared less organized than in healthy corneas and standard CXL-treated keratoconic corneas. Moreover, the distribution of CD34-positive keratocytes was improved in keratoconic corneas following ionto-CXL treatment, though a scattered CD34 immunoreactivity was still noticeable in the subepithelial stroma. This study provides histological evidence that ionto-CXL may represent a non-invasive alternative in the management of progressive keratoconus in adults.
authors.affiliation: Department of Experimental and Clinical Medicine, Section of Anatomy and Histology, University of Florence, Largo Brambilla 3, 50134 Florence, Italy.
authors.forename: Mirko
authors.initials: M
authors.lastname: Manetti
authors.affiliation: Eye Clinic, Department of Surgery and Translational Medicine, University of Florence, Largo Brambilla 3, 50134 Florence, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Favuzza
authors.affiliation: Department of Bioscience and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, Isernia, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Sgambati
authors.affiliation: Eye Clinic, Department of Surgery and Translational Medicine, University of Florence, Largo Brambilla 3, 50134 Florence, Italy.
authors.forename: Rita
authors.initials: R
authors.lastname: Mencucci
authors.affiliation: Department of Experimental and Clinical Medicine, Section of Anatomy and Histology, University of Florence, Largo Brambilla 3, 50134 Florence, Italy. Electronic address: mirca.marini@unifi.it.
authors.forename: Mirca
authors.initials: M
authors.lastname: Marini
mesh_terms: D003315:Cornea; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004553:Electric Conductivity; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007478:Iontophoresis / Q000592:standards*; D007640:Keratoconus / Q000188:drug therapy / Q000628:therapy*; D008875:Middle Aged; D012256:Riboflavin / Q000008:administration & dosage*; D014803:Vitamin B Complex / Q000008:administration & dosage
chemical_list: D003432:Cross-Linking Reagents; D014803:Vitamin B Complex; D012256:Riboflavin
keywords: Collagen cross-linking; Human cornea; Immunohistochemistry; Iontophoresis; Keratoconus; Keratocytes