In Vitro Study On The Clinical Related Factors Of Silicone Oil Emulsification

As the vitreous cavity is filled with silicone oil material is Polydimethylsiloxane (PDMS). Its basic molecular units is-(CH3) 2-Si-O-, The refractive index is 1.404 at 20℃, similar to vitreous 1.336. Silicone oil has good hydrophobicity, optical transparency, low toxicity, stable physical and chemical properties, physical inertia and effective surface tension and lasting action. It also can prevent bleeding and fiber contraction. So it has been widely used in clinical treatment of a variety of complex retinal detachment. But we cannot ignore the fact that there are many complications if silicone oil was filled in eye for a period of long time ignored. There's one of the more serious late complications is silicone oil emulsion.Most scholars believe that the silicone oil emulsion is a large bubble of silicone oil, which was injected into the vitreous cavity, was isolated stable opaque droplets. It presents a dust-like droplets attach to the eye tissue or spread into eyes.Emulsion particles swimming in the vitreous cavity, anterior chamber, adhesion in the retina and iris surface, causing the cornea, lens disease, or secondary glaucoma, which caused by trabecular meshwork obstruction, interference into the eye tissue physiological trigger a series of eye complications. So far the cause of silicone oil emulsion is difficult to conclude and Its incidence is about 0.7% to 40%. Silicone oil emulsion is one of the difficulties plagued ophthalmic clinicians eye in recent years. Silicone oil emulsion on experimental research and clinical observation is a hot topic at home and abroad in recent years.The experimental study is to analyze the clinical related factors on the emulsification of silicone oil in vitro. Such as balanced salt solution (balanced salt solution BSS), triamcinolone acetonide, perfluorodecalin, fresh serum and the alcohol, in the blood of patients with long-term drinking. Establish an effective in vitro model of silicone oil emulsion and provide the basis for the in-depth study of the prevention and treatment of silicone oil emulsification and improving the filling characteristics of intraocular for the future.Materials and MethodsWe use special 5ml volumetric flask as model of the human eye in vitro and add different interfering factors in it. Our model consisted of 4 ml of silicone oil and a 0.5 ml aqueous phase. The aqueous phase was prepared using pure balanced salt solution as a control group and varying quantities of triamcinolone acetonide, fresh serum, perfluorodecalin, anhydrous ethanol and BSS solution 0.5 ml as the experimental groups. For periods lasting from one week to eight weeks, the volumetric flasks were subjected to constant shear by placing them on a rotary shaker at a rate of 120 cycles per minute and incubated at 37℃. Gross and microscopic examinations of the volumetric flasks for early signs of oil-water emulsification were performed daily to quantify relative degrees of emulsification at one week, two week, four week and eight week.Results1. Comparison of results at different times for each groups was statistical significance (p<0.05). The results show that the emulsion particles are increased with time.2. Compared with BSS group, the number of emulsion particles in triamcinolone acetonide group are reduced at each time. The result shows statistically significant (p<0.05).3. The number of emulsion particles of perfluorodecalin group at each time are more than that of control group obviously. The result shows statistically significant (p <0.05).4. Compared with BSS group, the number of emulsion particles in fresh serum group are reduced at one week,two week and four week. The result shows statistically significant (p<0.05). In the eighth week, there is no difference between triamcinolone acetonide group and BSS group. The results do not shows statistically significant (t=-1.276,p> 0.05).5. Compared with BSS group, the number of emulsion particles in Anhydrous alcohol group are reduced at one week,two week and four week.The result shows statistically significant (p<0.05). In the eighth week, the number of emulsion particles in the Anhydrous ethanol group more than in the BSS group.The results shows statistically significant (t=-14.586, p<0.05).Conclusions1. We successfully established the model of the eye in vitro.Although it can not completely simulate in vivo environment of body, it can make unified of the many complicated factors. This method can be used to analyze the surgery-related exposure factors on contact with silicone oil emulsion performance.2. In the clinical sense, completely avoiding the contact with Interference factor is impossible. Perfluorodecalin may increase the silicone oil emulsion, so it should minimize the application in surgery; Intravitreal injection of triamcinolone acetonide, may reduce the incidence of silicone oil emulsion; Vitreous cavity effusion of blood components and alcohol components may affect the long-term silicone oil emulsion volume after surgery. Therefore, intraoperative or postoperative bleeding should be controlled and avoid alcohol.