The effects of Ozurdex® (dexamethasone intravitreal implant) on experimental proliferative vitreoretinopathy

Purpose: To investigate a new sustained-release formulation of dexamethasone (Ozurdex®) for inhibiting proliferative vitreoretinopathy (PVR) and its effect on the expression of retinal glial reaction and inflammation in experimental PVR eyes. Methods: We used 30 pigmented rabbits for this study. One week after gas compression, the eyes were injected with 5 × 10⁴ retinal pigment epithelial cells into the vitreous cavity to induce PVR. Concurrently, one eye also received an intravitreal injection of Ozurdex; the other eye was used as a control. PVR was graded by indirect ophthalmoscopy on days 1, 3, 7, 14, 21, and 28. The expression of the retinal glial reaction and inflammation in experimental PVR eyes were evaluated by Western blot analysis. Results: PVR severity increased gradually and peaked after 14 days, and no differences in PVR severity between the study and control groups were observed at any time point. The expression of glial fibrillary acid protein (GFAP) increased on days 7 and 14 in both the PVR control and study groups. While the use of Ozurdex in the study group showed less GFAP expression, this difference was not significant. The expression of tumor necrosis factor (TNF)-α and interleukin (IL)-6 significantly increased on days 7 and 14 in PVR control eyes. There was a significant difference in TNF-α between PVR control eyes and Ozurdex-treated eyes on days 7 (p < 0.001) and 14 (p = 0.019). Ozurdex in the study group showed lower IL-6 expression; however, this difference was not significant on days 7 (p = 0.063) and 14 (p = 0.052). Conclusions: The intravitreal injection of Ozurdex suppressed the expression of inflammatory markers; however, it did not mitigate the severity of experimental PVR in this animal model.