Silicone Oil-Related Visual Loss

Background: Silicone oil (SO) is used as an intravitreal tamponade agent in vitreoretinal surgery for rhegmatogenous retinal detachment (RRD) complicated by proliferative vitreoretinopathy or with large, multiple retinal tears. Usually, SO is left in the eye for at least 3 months. Although its use can lead to well-known complications, intraocular SO is generally well tolerated. Some studies have reported unexpected central vision loss after SO use or removal. Objective: To investigate and analyze the reason for visual loss after the use or removal of intraocular SO in patients who underwent vitrectomy surgeries for RRD. Patients and Methods: A retrospective observational case series of 12 patients with macula-on RRD who reported visual loss after the use or removal of SO was reviewed. Investigations carried out included fundus fluorescein angiography, optical coherence tomography (OCT) of the macula and optic disc, perimetry, and electrophysiological study. Electrolyte levels were measured in retro-oil fluid and compared with their levels in the vitreous humor of patients who underwent vitrectomy for macular holes, floaters, dropped intraocular lenses, or dropped crystalline lens fragments. Results: Visual acuity levels dropped by at least 2 Snellen chart lines. None of the 12 cases had macular detachment at any stage. Fundus fluorescein angiography and OCT results were unremarkable in most of the cases. Mean levels of electrolytes in retro-oil fluids and vitreous humor were similar. Conclusion: Visual loss is a possible complication after SO use or removal. This still remains a mysterious issue which needs further research and investigation. (C) 2017 S. Karger AG, Basel