Experimental Studies on the Retinal Responses to Intravitreal Perfluorocabon Liquids

ABSTRACT

Perfluorocarbon liquids (PFCLs) are useful tools during vitreous surgery for complicated retinal detachments. Generally, these liquids are used as short-term vitreous replacement without retinal toxicities. But long-term tolerance of intraocular fluorochemicals is not established. We evaluated long-term tolerances to intraocular perfluorophenanthrene(Vitreon) or perfluorodecalin(DK-line) in the rabbit retina for a period of up to 3 months. Three days after C3F8 gas-compression of the vitreous, 1.2ml of highly purified PFCLs were injected into 26 rabbit eyes. Control eyes received same volumes of balanced salt solution. Eyes were examined by indirect ophthalmoscopy and light and electron microscopy. Clinically PFCLs were emulsified and dispersed into small bubbles after 2-3 weeks. Mild posterior subcapsular cataracts and vitreous opacities were observed after long-term retention of PFCLs. Histopathologically, at 1 week after surgery, several epiretinal macrophages were present in both groups. Focal disarrangements of photoreceptors were observed in perfluorodecalintreated group. At I month after surgery, protrusion of Muller cell, dropdown of photoreceptor nuclei, loss of photoreceptors, outer and inner segments and retinal pigment epithelial hypertrophy were observed. In perfluorodecalin-treated group, atrophy in outer nuclear layer and thinning of all the retinal layers occurred. At 3 months after surgery, small oil-like droplets were scattered throughout the retinal layers and retinal pigment epithelium in perfluorodecalin-treated group. These findings were almost totally confined to the lower part of retina that has been long-term contact with the liquids. Our findings suggest that perfluorodecalin is more toxic to the retina than perfluorophenanthrene. Both liquids are not adequate for long-term vitreous replacement, but may be useful for short-term intraoperative use.