Purpose:
To investigate the presence of cholesterol and fatty acids(FAs) in the interface material between water and silicone oil in removed silicone oil..
Methods:
Hexan extracts were prepared from these interface materials and water phase of 25 cases. 11of 25 silicone oil samples(Group A), contained a opacified and gelatinous materialand Group B did not. GC, FT-IR and 1HNMR and13 CNMR spektroscopy were performed.The possibility of epoxigenase activation in tissues around the silicone oil was discussed by based on knowledge of the literature as a cause of plastification of FAs.
Results:
Group A cases were vitrectomized due to endophthalmitis, retinal detachment after failure of band cerclage and proliferative diabetic retinopathy.Group B had vitrectomized with or without band cerclage at the same intervention. of unsaturated fatty acids.Fig 1.The IR spectra of Group A,B(top right,bottom).Esterified FAs have-C=O- bonds(1745cm-1).-C=C- bonds(1637cm-1) and also -OH bands were around3200-3600cm-1.The existence of OH group indicates various reactions such as hydrolysis of ester, water in oil and epoxidation of unsaurated FAs. The mean of FAs ratios were 6.74%±0.65(6.08-7.52%) in Group A and 21.22%±1.67 (19.33-23.14%) in Group B(p=0.000).Fig2.A sample of 0-3.00ppm of Group B.The signals at 0.85t for the end -CH3 group and 1.13ppm,1.30ppm,1.42ppm and 1.6ppm as broadened singlets. were assigned to FAs in1H NMR spectroscopic(Fig1,top left). There is not any signals to be assigned to cholesterol in both of 1 HNMR and 13CNMR (120-130 ppm,Fig1,bottom left), the absence of cholesterol is accepted.
Conclusions:
Epoxigenase activity in the retina is not a studied subject In this study interface materials in removed silicone oils does not contain cholesterol and silicone does not effect oxidative stress and probably has no effectiveness on activity of epoxigenase.This study suggests that conditions creating high oxidative stress may lead to epoxigenase activity of endothelial cells in the vessels around the silicone oil.
Keywords: lipids • plasticity • oxidation/oxidative or free radical damage