title: In vivo and in vitro feasibility studies of intraocular use of seprafilm to close retinal breaks in bovine and rabbit eyes.
abstract: OBJECTIVE
  Seprafilm, a sodium hyaluronate/carboxymethylcellulose absorbable barrier developed to prevent adhesions after abdominal surgery, adheres well to wet tissue. The authors studied the efficacy of this film for sealing retinal breaks in animals.
  
  
  METHODS
  In an in vitro study, a retinal detachment with a hole was created in bovine eyecups after the vitreous gel was removed. Seprafilm was placed over the retinal hole, and the strength of the retinal adhesion was measured by pulling the film. Permeability was tested by applying methylene blue to the film covering the retinal break. Seprafilm also was soaked in balanced salt solution (BSS) incubated at 37 degrees C, and the pH of the BSS containing Seprafilm was measured as it melted. In an in vivo study, Seprafilm was powdered and mixed in BSS solution, and 0.1 mL was injected into the right vitreous cavity in study rabbits. The same amount of BSS was injected into the right vitreous cavity in control rabbits. Ophthalmologic examinations were performed. Bilateral electroretinograms were recorded simultaneously before and 6 weeks after injection. Both eyes were enucleated for histologic evaluation.
  
  
  RESULTS
  Seprafilm adhered well to the retina, was impermeable to methylene blue, and remained solid in BSS for 30 days before it dissolved, and its pH ranged from 7.2 to 8.0. No intraocular inflammatory reaction occurred after intravitreous injection of Seprafilm solution. There was no significant difference in amplitudes or implicit times of electroretinogram a-waves, b-waves, and oscillatory potentials before and after injection and between study and control groups. No significant retinal abnormality was detected by light microscopy in either group.
  
  
  CONCLUSIONS
  The film adhered well to the retina with no signs of ocular toxicities. Further study is warranted for possible means of patching retinal breaks.
authors.affiliation: Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Sueda
authors.forename: Toshiro
authors.initials: T
authors.lastname: Sakuma
authors.forename: Hajime
authors.initials: H
authors.lastname: Nakamura
authors.forename: Nari
authors.initials: N
authors.lastname: Usumoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Okuno
authors.forename: Mikki
authors.initials: M
authors.lastname: Arai
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Hirose
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D002417:Cattle; D004596:Electroretinography; D005240:Feasibility Studies; D006820:Hyaluronic Acid / Q000378:metabolism / Q000627:therapeutic use*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007267:Injections; D008567:Membranes, Artificial; D010539:Permeability; D011817:Rabbits; D012160:Retina / Q000503:physiopathology; D012167:Retinal Perforations / Q000503:physiopathology / Q000601:surgery*; D000267:Tissue Adhesions; D014343:Trypan Blue / Q000378:metabolism; D014822:Vitreous Body
chemical_list: D001672:Biocompatible Materials; D008567:Membranes, Artificial; C118198:Seprafilm; D006820:Hyaluronic Acid; D014343:Trypan Blue