I want to get a vitrectomy. How safe is it?

Depends . Most of the time vitrectomy is a safe procedure. It really depends on the reason for the surgery. If you have a complex retinal detachment, the surgery can be more difficult, if it is a surgery to specifically remove vitreous debris such as hemorrhages, it can be much simpler. Remember the risks which can include detachment, bleeding, infection, loss of vision, need for more surgery.
It Depends. Barry: every surgery has risks. It would be helpful to know what the underlying retinal condition is, to balance risks vs. Benefits. The risk of complications such as a retinal detachment or infection is rare, but they need to be taken into consideration when making a decision to proceed. Finally, the skill, training, and your trust in your retinal surgeon is a major factor. Good luck.
Very safe . If a vitrectomy is needed, it is very safe. There is small risk of bleeding, infection, retinal issues, and other problems though.