title: Biocompatibility of polyvinylalcohol gel as a vitreous substitute.
abstract: Polyvinylalcohol (PVA) hydrogel cross-linked by gamma irradiation was assessed as a possible vitreous substitute. From a series of experiments, rise of intraocular pressure and inflammatory changes in the vitreous cavity after operation were observed in some cases. Crab-eating macaques were used for this experiment. PVA gels were injected into vitreous cavity after vitrectomy and followed clinically by opthalmoscopy, tonometry, fundus photography, electroretinogram (ERG), chemotaxis, and flare cell meter. Histopathologic examination by light and electron microscopy was performed after 3 months. As a result, there were no significant changes in ophthalmoscopic findings. No abnormal rising of intraocular pressure (IOP) was recognized. ERG did not show meaningful amplitude weakness. From the photon counting of flare cell meter, significant break of blood-aqueous barrier and blood-retinal barrier was not observed. Histopathologic examination revealed that all layers of the retina were intact and no loss of tissue was evident. However, in PVA gel-injected eyes, some vacuolations of the inner retina were found in some specimens. To conclude, PVA gel was well tolerated in these experiments. The gel with a network similar to the vitreous body showed the best biocompatibility, though it is necessary to investigate the biocompatibility for the long-term. PVA gel is a good candidate for a vitreous substitute.
authors.affiliation: Department of Ophthalmology, Nara Medical University, Nara, Japan. smaruoka@naramed-u
authors.forename: Shinji
authors.initials: S
authors.lastname: Maruoka
authors.forename: Toyoaki
authors.initials: T
authors.lastname: Matsuura
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kawasaki
authors.forename: Masahiro
authors.initials: M
authors.lastname: Okamoto
authors.forename: Hara
authors.initials: H
authors.lastname: Yoshiaki
authors.forename: Makoto
authors.initials: M
authors.lastname: Kodama
authors.forename: Masaaki
authors.initials: M
authors.lastname: Sugiyama
authors.forename: Masahiko
authors.initials: M
authors.lastname: Annaka
mesh_terms: D000818:Animals; D000867:Anterior Chamber / Q000166:cytology / Q000187:drug effects; D001672:Biocompatible Materials / Q000494:pharmacology*; D018916:Blood-Aqueous Barrier / Q000187:drug effects; D004195:Disease Models, Animal; D004596:Electroretinography; D005782:Gels; D066298:In Vitro Techniques; D007267:Injections; D007429:Intraocular Pressure / Q000187:drug effects; D008252:Macaca fascicularis; D008297:Male; D008422:Materials Testing; D008854:Microscopy, Electron; D011142:Polyvinyl Alcohol / Q000494:pharmacology*; D011817:Rabbits; D012160:Retina / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D014821:Vitrectomy; D014822:Vitreous Body
chemical_list: D001672:Biocompatible Materials; D005782:Gels; C062364:polyvinyl alcohol hydrogel; D011142:Polyvinyl Alcohol