title: Biocompatibility of Ferrara intracorneal ring segment with and without chondroitin sulfate coating. Clinical and histopathological evaluation in rabbits.
abstract: OBJECTIVE
  To investigate and compare the biocompatibility of two types of Ferrara intracorneal ring segment: with and without chondroitin sulfate coating by clinical and histopathological evaluation.
  
  
  METHODS
  A randomized experimental study was carried out on thirty right-eye corneas from 30 Norfolk albino rabbits allocated into two experimental groups: Group G1 - implanted with Ferrara intracorneal ring segment without coating (FICRS) and Group G2 - implanted with Ferrara intracorneal ring segment with chondroitin sulfate coating (FICRS-CS). Left eyes formed the control group. Clinical parameters analyzed were: presence of edema, vascularization, infection and ring extrusion one, 30, and 60 days after surgery. Histopathological parameters analyzed were: number of corneal epithelial layers over and adjacent to the ring, presence of spongiosis, hydropic degeneration, basement membrane thinning, inflammatory cells, neovascularization and pseudocapsule formation.
  
  
  RESULTS
  At clinical examination 60 days after implant, edema, vascularization and extrusion were observed respectively in 20%, 26.7%, 6.7% of FICRS corneas and in 6.7%, 6.7%, and 0% of FICRS-CS corneas. Histopathological evaluation showed epithelial-layer reduction from 5 (5;6) to 3 (3;3) with FICRS and from 5 (5;5) to 4 (3;5) with FICRS-CS in the region over the ring. Epithelial spongiosis, hydropic degeneration, and basement membrane thinning were present in 69.2%, 53.8%, and 69.2% of FICRS and in 73.3%, 73.3%, and 46.7% with FICRS-CS, respectively. Vascularization was present in 38.5% of FICRS and 13.3% with FICRS-CS, inflammatory cells in 75% of FICRS and 33.3% with FICRS-CS, and pseudocapsule in 66.7% of FICRS and 93.3% with FICRS-CS. Giant cells occurred only in the FICRS-CS group (20%).
  
  
  CONCLUSIONS
  Ferrara intracorneal rings coated with chondroitin sulfate (FICRS-CS) caused lower frequency of clinical and histopathological alterations than Ferrara intracorneal rings without the coating (FICRS), demonstrating higher biocompatibility of the FICRS-CS.
authors.affiliation: Postgraduate Program in Surgery, Faculty of Medicine of Botucatu (FMB), Sao Paulo State University (UNESP), Botucatu-SP, Brazil.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Andreghetti
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Maria Aparecida Custódio
authors.initials: MA
authors.lastname: Domingues
authors.forename: Vitor Andrigheti Coronado
authors.initials: VA
authors.lastname: Antunes
authors.forename: Paulo de Souza
authors.initials: Pde S
authors.lastname: Segundo
authors.forename: Maria Rosa Bet de Moraes
authors.initials: MR
authors.lastname: Silva
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use*; D002809:Chondroitin Sulfates / Q000627:therapeutic use*; D003316:Corneal Diseases / Q000601:surgery; D003319:Corneal Stroma / Q000033:anatomy & histology / Q000601:surgery*; D005260:Female; D008422:Materials Testing; D019736:Prostheses and Implants; D017755:Prosthesis Fitting; D019919:Prosthesis Implantation / Q000379:methods*; D011817:Rabbits; D011897:Random Allocation; D012016:Reference Values; D015203:Reproducibility of Results; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D001672:Biocompatible Materials; D002809:Chondroitin Sulfates