Intravitreal silicone oil achieves an effective endotamponade in patients with complex retinal detachments. Silicone oil displacement into the anterior chamber risks glaucoma and endothelial failure. We describe a 52-year-old patient with pseudophakia with silicone oil endotamponade presenting with visual loss and intraocular pressure of 60 mm Hg. Inferior YAG iridotomy was undertaken to repatriate silicone oil to the posterior segment. Despite normal intraocular pressure, acute corneal oedema occurred postiridotomy, resolving spontaneously over 2 weeks. Pupil block glaucoma secondary to silicone oil requires a management approach based on an understanding of silicone oil fluidics. Careful selection of inferior laser iridotomy site is critical to effectively reverse pupil block. Anterior migration of silicone oil in patients with pseudophakia is rare. We offer an hypothesis to explain unanticipated transient corneal oedema following silicone oil displacement from the anterior chamber. Clinicians must discuss the possibility of transient or permanent endothelial failure preoperatively in this patient group.