title: Tolerance of extended-term vitreous replacement with perfluoro-n-octane and perfluoroperhydrophenanthrene mixture (phenoctane).
abstract: OBJECTIVE
  To improve the surface visibility of perfluoroperhydrophenanthrene, we added various percentages of perfluoro-n-octane.
  
  
  METHODS
  Twenty New Zealand white rabbit eyes underwent gas vitrectomy. One milliliter of balanced salt solution was injected into each Group 1 eye as control. Perfluoro-n-octane was added to perfluoroperhydrophenanthrene in ratios of 15:85, 25:75, and 50:50; 1 mL of each mixture was injected into the vitreous cavities of Groups 2, 3, and 4, respectively. Eyes were examined clinically and electroretinograms were performed before and 4 and 8 weeks after injection, when the rabbits were killed. Eyes were processed for light and transmission electron microscopy (TEM).
  
  
  RESULTS
  The indices of refraction of the 15:85, 25:75, and 50:50 mixtures were 1.3275, 1.3191, and 1.3026, respectively, and the mixtures were visible in the vitreous cavity. Emulsification and mild-to-moderate dust-like opacities were observed in eyes from Groups 2 through 4; vitreous strands formed in four of the Group 4 eyes. The retinae were attached. Electroretinographic responses were normal, except in one eye with cataract. Light microscopy showed normal retinal architecture, with some macrophages with intracytoplasmic vacuoles on the surface of the inferior retina or in the vitreous cavity. Fingerprint disfigurement of photoreceptor outer segments was seen in some Group 3 and 4 eyes under TEM.
  
  
  CONCLUSIONS
  Minimal changes were induced by the 15:85 mixture in the rabbit eye. The mixtures of 25:75 and 50:50 produced some ultrastructural changes of the retina. The mixtures were visible under water.
authors.affiliation: LSU Eye Center, Louisiana State University Medical Center School of Medicine, New Orleans 70112-2234, USA.
authors.forename: C
authors.initials: C
authors.lastname: Liang
authors.forename: G A
authors.initials: GA
authors.lastname: Peyman
mesh_terms: D000818:Animals; D004338:Drug Combinations; D004596:Electroretinography; D005123:Eye / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D005466:Fluorocarbons / Q000494:pharmacology*; D007267:Injections; D008854:Microscopy, Electron; D011817:Rabbits; D014821:Vitrectomy
chemical_list: D004338:Drug Combinations; D005466:Fluorocarbons; C073608:perfluorooctane; C047722:perfluorophenanthrene