Intraocular tissue migration of silicone oil after silicone oil tamponade: A histopathological study of enucleated silicone oil-filled eyes

Abstract

Retrospective clinical and histopathological review of eight silicone oil-filled enucleated eyeballs using light microscopy was carried out in our department of ocular pathology during a period of six years. In all cases, silicone oil vacuoles, both free and incorporated within macrophages were seen in all the retinal layers. Silicone oil vacuoles were seen in the optic nerve, choroid, retinal pigment epithelium, corneal stroma, iris and ciliary body stroma, preretinal and subretinal membranes and retro-corneal membranes. Silicone oil migration could be seen in intraocular tissues as early as two months post surgery. There was no definite histopathological correlation between duration of tamponade and distribution of silicone oil vacuoles. Silicone oil vacuoles were seen in the optic nerve in eyes with neovascular glaucoma. Chronic inflammatory reaction was observed in the retinal tissue in the vicinity of silicone oil vacuoles.

Increased Retinal Thinning after Combination of Internal Limiting Membrane Peeling and Silicone Oil Endotamponade in Proliferative Diabetic Retinopathy

“…The mechanism of how SO endotamponade causes retinal thinning remains unclear. Previous studies have shown the migration of SO into the ocular tissues, including the optic nerve, and the subsequent induction of an inflammatory response mediated by macrophages in several human and animal studies [12][13][14][15][29][30][31][32] ; however, retinal thinning occurs not only in severe cases but also in mildto-moderate cases; thus, it is difficult to conclude that SO intraretinal infiltration is the only cause for the retinal thinning. There have also been reports on the changes in visual outcome and retinal thickness caused by treatment with SO endotamponade.…”

Silicone Oil Migrating From Intraocular Tamponade Into the Ventricles

“…Because there is essentially no normal anatomical communication between the globe and the intracranial subarachnoid space, they hypothesized a route of entry based on pathological findings of migration of silicone vesicles into the optic nerve parenchyma in enucleated globes after silicone tamponade. 3,6 They speculated that the silicone might have entered the optic nerve through the atrophic optic disc as a result of increased intraocular pressure, then coalesced, and eventually migrated into the perioptic subarachnoid space. Communication between the perioptic and subarachnoid spaces would allow silicone to enter the ventricles.…”

Inhibition of migration but stimulation of proliferation of human retinal pigment epithelial cells cultured with uniform vesicles of silicone oil

“…But long-term silicone oil tamponade could evoke a series of complications, and the emulsification of silicone oil is a grave one. Some researchers reported that VSO were found on retinal surface, intraretina and in optic nerve after silicone oil was removed from patients [14][15][16][17]. The hRPE cells we obtained were from normal individuals, and they could indicate normal behavior.…”