Abstract
Purpose:
To examine the biocampatibility of Siluron Xtra® (Fluoron, Ulm, Germany), a silicone oil used as a vitreous substitute in vitreo-retinal surgery, on porcine retinal tissue in vitro.
Methods:
Retinal tissue of 37 porcine eyes was immediately prepared post mortem and placed into Minucell perfusion systems (Minucell, Bad Abbach, Germany) to be perfused with liquid culture medium over a period of 4-8 days. 23 retinal tissue samples including retinal pigment epithelium (RPE) were covered by silicone oil (group 1) during the perfusion and compared to a control group of 7 samples (group 2), without silicone oil. Group 3 included 7 single RPE tissues without retinal tissue layer, in direct contact with silicone oil, thus imitating a retinal tear, during the perfusion.<br /> The morphology of the retina and RPE was examined by light microscopy and stained with immunohistochemical markers to determine Müller cell damage in the retina with Glial fibrillary acidic protein (GFAP) and proliferation in the RPE with the Ki67 protein.<br />
Results:
Ki67 staining showed significantly less proliferation in the tissue covered by silicone oil (group 1) compared to the control samples in group 2 (p=0,001).<br /> Direct contact of silicone oil and RPE (group 3) showed no significant increase in proliferation compared to the controls (p=1).<br /> GFAP staining also did not show any significant Müller cell damage related to Siluron Xtra®(p=0,9).<br /> No structural changes in the retinal tissue were observed related to silicone oil by HE staining.
Conclusions:
The results of our in vitro examination verified good structural biocompatibility of<br /> silicone oil (Siluron Xtra®) on porcine retina and RPE in vitro. Furthermore, silicone oil may exert a protective layer preventing proliferation on retinal tissue.<br /> Further examination of other silicone oils and alternative vitreous substitutes, such as gas and water, are necessary to determine the protective advantage of Siluron Xtra® on retinal tissue proliferation.