THE EFFECT OF CHEMICAL-STABILITY AND PURIFICATION OF PERFLUOROCARBON LIQUIDS IN EXPERIMENTAL EXTENDED-TERM VITREOUS SUBSTITUTION

Background: To determine the importance of chemical stability and puri fication of perfluorocarbon liquids (PFCLs) in experimental retinal to lerance, we tested four different substances as long-term vitreous tam ponade: purified and nonpurified perfluorodecalin (PFD) and perfluoro- octyl-bromide(PFOB) Method: After mechanical vitrectomy we replaced th e vitreous of 65 rabbit eyes. Five groups were formed; four of them re ceived the four PFCLs, while one served as control and received Ringer solution. The eyes were observed clinically every week and examined h istologically after 1, 2, 4 and 8 weeks Results: After 1 week we obser ved foam cells and intraretinal macrophages in all eyes with PFCLs. Pu rified PFD caused retinal lesions in the photoreceptor, ganglion cell and outer nuclear layers after only 2 weeks in the lower part of the e yes. In eyes filled with purified PFOB we observed more pronounced dam age of the same nature. Unpurified substances caused severe inflammati on and retinal detachment Conclusion: Our study demonstrates that puri fication and chemical stability are important factors in retinal toler ance of PFCLs for vitreous replacement. Although purified PFD was tole rated by the rabbit eyes for 1 week, we cannot recommend this substanc e for short-term clinical use as a vitreous substitute.