The concept of heavy tamponades-chances and limitations.
BACKGROUND
Proliferative vitreoretinopathy in the inferior retina remains clinically challenging. Heavier than water intraocular tamponades have been developed to improve inferior tamponading properties. In addition to inferior PVR, there seem to be other applications such as persistent macular holes or PVR in trauma eyes.


METHODS
Review of the literature on clinical application of heavy tamponades. The review also discusses the theoretical background of heavy tamponades and possible future developments.


RESULTS
The parameters of an optimal intraocular tamponade are defined, and the influences of the specific gravity, buoyancy, interfacial tension, and viscosity are discussed. Perfluorocarbon liquids and partially fluorinated alkanes were associated with tamponade emulsification, intraocular inflammation, and rise in intraocular pressure that was less prominent in admixtures of these substances with silicone oil (heavy silicone oils). Two recently developed heavy silicone oil tamponades, Oxane HD and Densiron 68, are well-tolerated and have entered clinical practice. The side effects are associated with the chemical properties of the tamponading agent, and seem comparable to the ones seen with conventional silicone oil.


CONCLUSIONS
Heavy silicone oil tamponade improves inferior tamponade, and may be considered a new generation of intraocular tamponades.
Joussen
Antonia M
AM
Department of Ophthalmology, University of Duesseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany. joussena@googlemail.com
Wong
David
D
D000818:Animals; D005466:Fluorocarbons / Q000737:chemistry / Q000627:therapeutic use*; D006801:Humans; D012164:Retinal Diseases / Q000628:therapy*; D012827:Silicone Oils / Q000737:chemistry / Q000627:therapeutic use*; D013046:Specific Gravity; D013500:Surface Tension; D014783:Viscosity
D005466:Fluorocarbons; D012827:Silicone Oils; C515608:densiron