Vitreous replacement.

The long list of substances used by ophthalmologists for vitreous replacement can be reduced to only three for four. Their use depends upon the surgical procedure. After trauma or cataract extraction and in vitreous surgery, saline is the best substitute; it is rapidly replaced by aqueous humour and no inflammatory reaction occurs. Retinal detachment surgery requires a highly viscous material, harmless to ocular tissues, and these criteria are met by Healon H. Whenever highly viscous hyaluronic acid is available, it should be used instead of saline or air (Regnault and Brégeat, 1973). Sulphahexafluoride gas has also been used to treat these difficult cases of retinal detachment but further experience is needed before a definite conclusion can be reached.