Abstract
Abstract: :
Purpose: Silicone oils (polymethylsiloxanes) have been used in the treatment of complicated retinal detachments for over 30 years 1. Various ocular complications have been described with their long term use including cataracts, acute and chronic glaucoma, corneal decompensation and optic atrophy1-4. Its migration into the brain has also been reported before.3 We report another case of intracranial migration of silicone oil in a patient who went blind following a repeat vitrectomy and discuss the relevant pathologic mechanisms and safety issues surrounding use of silicone endotemponade in retinal detachment surgery. Methods: Retrospective case review and Magnetic resonance imaging with standard T1 and T2 weighted sequences and gadolinium enhanced sequences and special silicone sequences study the optic nerve and review of the literature reagrding silicone oil spread into the CNS were performed. Results Case Report A 73 year old woman underwent a left eye pars plana vitrectomy(PPV)+20% C3F8 injection for a full thickness macular hole. Three months later she underwent a repeat PPV with silicone oil injection following a retinal detachment. Postoperatively she developed raised IOP and lost vision in her affected eye one week after surgery. Fundoscopy showed a pale cupped disc and MRI revealed migration of silicone oil along the optic nerve and the subarachnoid space and in the supracellar cistern. Conclusions: Inspite of MRI evidence of silicone oil migration into the optic nerve and subarachnoid space the exact mechanism of our patients optic neuropathy is still unknown. It might have been due to direct damage from raised IOP or a vascular event (non arteritic ischaemic optic neuropathy ) or due to toxicity of Silicone oil or a combination of the above.We think that it is probably still safe to continue using silicone oil for endotemponade in difficult retinal detachment surgeries but one needs to be vary of its use in glaucoma patients/suspects and also monitor the IOP carefully to avoid pressure rises. It's potential for spread might be an issue to be discussed with patients prior to obtaining consent. References: 1.Shields C, Eagle R. Pseudoschnabel's cavernous degeneration of the optic nerve secondary to intraocular silicone oil. Arch Ophthalmol 1989;107:714-717. 2.Budde M, et al.Silicone Oil-associated Optic Nerve Degeneration. Am J Ophthalmol 2001;131:392-394. 3.Eller AW et al. Migration of Silicone Oil into the brain: a Complication of intraocular silicone Oil for Retinal Tamponade. Am J Ophthalmol 2000;129:685-688. 4.Champion R et al. Peritonial reaction to liquid silicone: an experimental study. Graefe's Arch Clin Exp Ophthalmol 1987; 225: 141-145
Keywords: retinal detachment • vitreous substitutes