Chemical impurities and contaminants in different silicone oils in human eyes before and after prolonged use

Background Intraocular silicone oil (SiO) impurities as low molecular weight components (LMWC) and residual catalysts are thought to cause ocular toxicity. A case-control study was initiated to determine if highly purified SiOs of equal viscosity from two different manufacturers had a similar chemical stability after prolonged clinical use as a vitreous substitute in patients. Methods Medical grade samples of AcriSilOl 5000 (ASO 5000) and Vitreocrom 5000 (VC 5000) were obtained. Gas chromatography/flame ionisation detection (GC/FID) analyses were used to detect and characterize the LMWC (D4-D7 Siloxane fractions) and quantify the cholesterol level in the extracted SiOs as well as in the original SiO samples. Results The concentration levels of LMWC D4 and D7 fractions of the original SiO samples already showed a significant difference ( p