Biocompatibility of Ferrara intracorneal ring segment with and without chondroitin sulfate coating: clinical and histopathological evaluation in rabbits

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:30:35Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:43:30Z : No. of bitstreams: 1 2-s2.0-84883645775.pdf: 1430537 bytes, checksum: be814d3a2faed94d06e76f67ab70f8a7 (MD5) Made available in DSpace on 2014-05-27T11:30:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-09-01 PURPOSE: 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%). CONCLUSION: 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. Sao Paulo State University (UNESP), Botucatu-SP FMB UNESP, Botucatu-SP Division of Ophthalmology, Department of Ophthalmology Otolaryngology and Head and Neck Surgery FMB, UNESP, Botucatu-SP Sao Paulo State University (UNESP), Botucatu-SP FMB UNESP, Botucatu-SP Division of Ophthalmology, Department of Ophthalmology Otolaryngology and Head and Neck Surgery FMB, UNESP, Botucatu-SP