Lipophilic Substances in Intraocular Silicone Oil

Purpose To examine intravitreal silicone oil samples for lipophilic substances, including cholesterol, fatty acids, and derived methyl esters. Design Clinical interventional case series study. Methods The study included 53 patients (53 eyes; mean age 57.6 years) who underwent removal of intravitreal silicone oil used for intraocular tamponade with pars plana vitrectomy for retinal detachment. The silicone oil was removed 8.3 ± 5.7 months after pars plana vitrectomy and analyzed using gas chromatography with a flame ionization detector. Results Cholesterol was present in all samples with a mean concentration of 65 ± 32.3 μg/ml (95% confidence interval: 56.1 to 73.9 μg/ml). The concentration increased ( P < .001) with the time of tamponade, and decreased ( P = .003) with the age of the patients. Fatty acids along with derived methyl acids were detected in low concentrations in 49 samples (92.5%). Conclusions Cholesterol and lipophilic acids accumulate in intravitreal silicone oil used in intraocular tamponade.