Background: Perfluorocarbon liquids are established tools for intraoperative hydrokinetic retinal manipulation. Because of their high specific gravity, however, they may well cause mechanical damage to the retina when applied as a long-term vitreous substitute. Perfluorohexyloctane, a semi-fluorinated liquid fluorocarbon of low specific gravity (1.35 g/cm3), was developed as a long-term vitreous substitute. The current study was performed to investigate intraocular tolerance to perfluorohexyloctane as a long-term vitreous substitute in the experimental animal.
Methods: 34 vitrectomised eyes of pigmented rabbits underwent intravitreal injection of 1.0-1.2 ml perfluorohexyloctane or balanced salt solution. In 5 eyes the anterior chamber was filled. During the follow-up period of 3 months, the eyes were examined by slit lamp biomicroscopy, by fluorescein angiography and by electroretinography. The eyes were then enucleated and processed for light- and electron microscopy.
Results: Perfluorohexyloctane depicted dispersion beginning between the first and third week. Over a period of 9 weeks no toxic effect on retina, lens and cornea was noticed. At 14 weeks ERG showed a slight decrease in amplitude and early morphological changes in the retina.
Conclusion: Our findings suggest that perfluorohexyloctane is tolerated in the rabbit eye for 9 weeks. Since avascular rabbit retina is more susceptible to mechanical and toxic damage than vascularized primate retina, we suggest proceeding from here, and investigating tolerance and quality of tamponade of perfluorohexyl octane in man for up to 9 weeks.