What is vitrectomy surgery and how is it done?

Microsurgery. It is an outpatient operation in which microscopic instruments are used to remove the vitreous gel and manipulate other tissues. The surgery is done with the patient sedated, lying under a powerful microscope. As you can appreciate from the schematic, operating in that small space requires steady hands. The patient goes home with a patch and drops to help healing. It is usually not painful.
Umm.... Vitreous is the gel the fills the eye. It is removed with a high speed cutting/sucking instrument inserted about 3.5 mm back from the cornea, along with a irrigator and a light source--3 ports in all.