Purpose: To report the frequency and extent of silicone oil migration into the optic nerve during silicone oil endotamponade.
Methods: Histopathologic analysis of 74 eyes enucleated after silicone oil endotamponade.
Results: In 14 of 74 enucleated eyes (24%), optically empty vacuoles regarded as silicone oil vacuoles were observed in the retrolaminar optic nerve. In three eyes, silicone oil in the optic nerve was surrounded by a granulomatous inflammatory reaction. In serial cross sections, the vacuoles extended up to the line of surgical transsection (up to 9 mm) of the optic nerve and constituted up to 40% of the total cross-sectional area.
Conclusions: After silicone oil endotamponade, silicone oil may replace a considerable amount of tissue of the retrolaminar optic nerve. A granulomatous inflammatory reaction surrounding silicone oil may add to optic nerve damage.