Surgical Treatments in the Late Infection of Hydroxyapatite Orbital Implants

PURPOSE: We experienced six cases of late infection of the hydroxyapatite (HA) orbital implant treated with surgical procedures. METHODS: Exposures of the HA and pyogenic granulomas around conjunctival dehiscence helped us to confirm infections of the HA orbital implants. Infections were not controlled by medical therapies so the HA implants were exchanged by silicone implants in all cases. Finally, the silicone implants were replaced by Medpor(R) after the inflammation had been controlled. Dermis fat graft was also performed in two cases due to insufficient conjunctival sac. RESULTS: Infections of HA orbital implants occurred at 62 to 106 months postoperatively. Staphylococcus aureus and Pseudomonas aeruginosa were cultured from removed implants. All cases show successful outcomes during 12 to 42 months after Medpor(R) implantations. CONCLUSIONS: Infections of peg-inserted HA orbital implants occurred after five years due to exposure of HA orbital implants. To replace infected HA implants with Medpor(R) implants is considered a functionally and aesthetically effective therapeutic method.

The Effects of Tranilast(R) on the Cellular Proliferation, Collagen Synthesis, and Secretion of TGF-beta1 in Bovine Retinal Pigment Epithelial Cells

PURPOSE: To evaluate the effects of Tranilast(R) on the cellular proliferation, collagen synthesis, and secretion of transforming growth factor-beta1 on retinal pigment epithelial cells that influence the development of proliferative vitreoretinopathy in vitro. METHODS: After bovine RPE cells were isolated, they were exposed to Tranilast(R) 0.05, 0.1, 0.2, 0.4, 0.8, 1.0, 1.6 mg/ml and only DMEM which was used as control. MTT was used as a measurement of metabolic activity, and collagen synthesis and TGF-beta1 secretion were assayed by collagen kit (Sigma, USA) and TGF-beta1 kit (Gibco, USA). Western blot assay was used to confirm TGF-beta1, which was expressed by treated Tranilast(R) in bovine RPE cells. RESULTS: The higher the concentration of Tranilast(R), the more the inhibition of the cellular proliferation. LD50 concentration was about 1.0 mg/ml, and there was more significant difference the concentration of over Tranilast(R) 0.4 mg/ml than control (P<0.05). The higher the concentration of Tranilast(R), the more the inhibition of collagen synthesis and TGF-beta1 secretion from RPE cells, especially over Tranilast(R) 0.05 mg/ml (P<0.05). There was no response of TGF-beta1 expression in the concentration of Tranilast(R) 0.2 mg/ml compared to untreated bovine retinal epithelial cells. CONCLUSIONS: Tranilast(R) has a tendency of inhibitory effect in the cellular proliferation, collagen synthesis, and TGF-beta1 secretion. Tranilast(R) may prevent excessive proliferation of RPE and scar formation concerned with collagen synthesis and TGF-beta1 secretion in the proliferative vitreoretinal diseases.