Long-term exposure of the rabbit eye to silicone oil causes optic nerve atrophy.
A silicone oil endotamponade following vitrectomy has for decades been a standard method in human ophthalmology with a view to restoring a detached retina. However, severe functional deficiencies may remain after treatment. In adult rabbits, the injection of silicone oil into the eye-ball following vitrectomy resulted in a decrease of 89% in the number of myelinated optic nerve fibres after a survival time of 1 year (418,313+/-29,703 versus 45,620+/-23,905). Concomitantly, the cross-sectional area of the optic nerve was also reduced significantly (0.853+/-0.159 mm2 versus 0.355+/-0.107 mm2). The number of non-neuronal elements of the optic nerve remained virtually unchanged immediately behind the eye-ball and in the middle part of the nerve, whereas it increased significantly close to the optic chiasm (3040+/-433 versus 3888+/-403). Thus, destruction of the myelinated optic nerve fibres is likely to be responsible for the functional deficiencies observed after silicone oil implantation.
Department of Ophthalmology, Semmelweis University, Tömo u. 25-29, Budapest H-1083, Hungary. pappand@szem1.sote.hu
András
A
Papp
Evelyn B
EB
Kiss
Orsi
O
Tímár
Eszter
E
Szabó
Arpád
A
Berecki
Jeannette
J
Tóth
Jeno
J
Páli
D000818:Animals; D001284:Atrophy / Q000139:chemically induced; D005123:Eye / Q000187:drug effects*; D008297:Male; D009900:Optic Nerve / Q000473:pathology*; D011817:Rabbits; D012827:Silicone Oils / Q000633:toxicity*
D012827:Silicone Oils