The changes in physical properties of silicone oil after intraocular tamponade

Abstract

Objective To observe the changes in physical properties of silicone oil after intraocular tamponade. Methods The silicone oil was removed from 99 patients (99 eyes) of primary retinal detachment with 23G vitreous cutter system. The upper silicone oil was collected after put the vitrectomy samples at room temperature for 3 days. According to the time of intraocular tamponade, the silicone oil samples were divide into six groups including group A (1 month, 12 samples), group B (2 months, 15 samples), group C (3 months, 25 samples), group D (6 months, 22 samples), group E (1 - 2 years, 13 samples) and group F (above 2 years, 12 sample). Fresh unused silicone oil was set as blank control group. Then the emulsion particles, kinematic viscosity, surface tension, density, transmittance and refractive index were measured. Results The difference between group A - F and the control was statistical significant (P 0.05). The number of silicone oil emulsion particles has no statistical difference between group A and the control (P>0.05), but was significantly different between group B - F (P 0.05), but was significantly different between group C - F (P 0.05), but is significantly different between group E and F (P 0.05), but was significantly different between group E and F (P 0.05). Conclusions The physical properties of silicone oil will change during the intraocular tamponade. The emulsion particles number will increase and the transmittance will decrease after 2 months, the kinematic viscosity of silicone oil will decrease significantly after 3 months, and the density and surface tension will change significantly after 1 year of tamponade. Key words: Silicone oils/therapeutic use; Silicone oils/ adverse effects