Background: Heavy oil formation was found in the subretinal space in three patients with repeated vitreoretinal surgery. Cases: These patients had received perfluorocarbon liquid ( PFL) and silicone oil injection for retinal detachment in a previous surgery. Observations: A transparent " heavy density" oil bubble was found in the subretinal space in these patients. The heavy oil bubble was eventually removed by manual aspiration with a blunt-tipped 21-gauge needle. The retinas were reattached in all three cases. Conclusions: Silicone oil may mix with incompletely removed PFL to form heavy oil. During reoperation for persistent retinal detachment, these substances should be specifically sought and removed. (C ) Japanese Ophthalmological Society 2004
