Purpose: Cases of sudden loss of central vision in eyes with silicone oil in situ and after oil removal have been described. The aim of this review is to present current data on silicone oil toxicity to the neuronal aspects of the retina as well as the Cleveland Clinic Abu Dhabi experience with this retinopathy (maculopathy).
Methods: A PubMed review using the terms "silicon oil" and/or "toxicity" and/or "ganglion cell" and/or "nerve fiber" was conducted to identify case reports, case series, and original articles presenting toxicity from silicon oil. Timing of visual loss, as well as SD-OCT data and RNFL/GCC analysis, was collected. Selected cases were pooled from Cleveland Clinic Abu Dhabi Vitreoretinal database to further reinforce the findings.
Results: Twenty-four papers were identified (case/series/articles). The earliest papers that met our criteria seemed to report vision loss at the time of or after silicone oil removal; however, more recent studies have described such toxicity from 1 to 6 months after tamponade with silicone oil in situ. Since the first description of central visual loss from silicone oil, all researchers describe a thinning of perifoveal ganglion cells measured with SD-OCT, while there is no concordance as far as RNFL changes, with some authors describing a thinning and others a thickening, but neither was ever clearly associated with visual loss. The correlation between SD-OCT hyperreflective goblets in the inner retina and histological description of intraretinal oil droplets migration seems to suggest instances of silicone oil penetration in the retinal layers.
Conclusion: In a small percentage of cases who underwent retinal tamponade with silicone oil, ganglion cells can suffer a direct damage either from particles of oil that migrate in the retina or from direct contact with it. Indirect damage may be caused by phototoxicity due to the transparent nature of silicon oil or by inflammatory damage from cytokines sandwiched between oil and retina.
Keywords: Ganglion cells; Nerve fiber layer; Optical coherence tomography; Silicone oil.