Multinucleated giant cells in periretinal silicone granulomas are associated with progressive proliferative vitreoretinopathy.

PURPOSE: To determine the histologic features of granulomatous reactions in persilicone periretinal proliferation. PATIENTS AND METHODS: This retrospective study included 12 patients with recurrent retinal detachment and persilicone granulomatous proliferation after vitrectomy for proliferative vitreoretinopathy (PVR). All patients underwent reoperation for membrane surgery. Immunohistochemical study of the excised periretinal membranes was performed with cytokeratins, GFAP, vimentin, CD68, CD45, and lysozyme antibodies.
RESULTS: The cellular characteristics of periretinal granulomas allow differentiation of two types of tissue. Spongy tissue (nine cases) showed an accumulation of mature vacuolated macrophages that contained silicone without multinucleated giant cells (MGC). The second type (three cases) consisted of an accumulation of sparsely vacuolated macrophages, epithelioid cells, and MGC. The MGC corresponded to transition forms of foreign body giant cells (FBGC). Spongy tissue was associated with anatomic success (58.3% of cases) and with stabilized PVR (66.7% of cases) at the time of the membrane surgery. MGC were associated with prolonged silicone oil tamponade, recurrent retinal detachment, and progressive PVR.
CONCLUSIONS: Intraocular silicone oil can lead to periretinal foreign body granulomas. FBGC are occasionally observed and were associated with progressive PVR.