Background: Oxane HD(R) is a "heavier-than-water" silicone oil which has a specific gravity of 1.02 g/cm(3). When dispersed into droplets, one expects them to sink. We report a case of emulsification of Oxane HD in an eye that unexpectedly manifested as an "inverted hypopyon".
Methods: The clinical findings of a 45-year-old man who underwent pars plana vitrectomy and Oxane HD endotamponade for a phakic inferior rhegmatogenous retinal detachment are described.
Results: A large silicone oil globule was noted to be floating in the anterior chamber on postoperative day 1. Emulsification of the globule and inverted hypopyon formation were subsequently observed at 2 months postoperatively.
Conclusions: Emulsification and inverted hypopyon formation in the anterior chamber may occur with Oxane HD. One explanation might be that the Oxane HD has separated out into its constituent components of silicone and RMN3, which raises questions as to the basis for its claim to be a heavier-than-water tamponade.