Vitrectomy surgery is the basis for many different types of retinal surgery, including repair of retinal detachment, repair of macular hole, removal of epiretinal membrane, and removal of vitreous hemorrhage.
The back part of the eye (the vitreous cavity) contains the vitreous gel, a clear substance which is 99% water. "Vitrectomy" refers to removal of this gel. In the operating room and using a microscope, the surgeon usually makes three small openings in the white part of the eye (sclera). These openings are approximately the size of the needles used to draw blood from your arm. The surgeon uses various fine instruments including lights, suction, scissors, forceps and laser probes to perform surgery. At the end of surgery, the gel is not replaced. The eye produces its own fluid, and in some cases the surgeon may leave a bubble of air or gas inside the eye, which the body will absorb and replace with clear fluid. In some complex surgeries, the surgeon may leave the eye filled with silicone oil, which provides long term support to the retina but which requires an additional surgery to remove.
In most cases, vitrectomy refers to much more than just removal of the gel. For example, an epiretinal membrane is removed using tiny forceps, or heavy liquid may be used to flatten a retinal detachment, and laser may be used to seal a tear in the retina. In all of these cases, the gel must be removed before these other steps are possible, and so all of these procedures are referred to broadly as vitrectomy.
The greatest risks of vitrectomy are infection, retinal detachment or bleeding. The chance of these problems is less than 1 in 4,000, and permanent vision loss may occur in these situations. Patients are given medications before, during and after surgery in order to reduce the chance of such complications.
For patients who have not previously had cataract surgery, vitrectomy surgery almost always accelerates the progression of cataract in the operated eye. Consequently, cataract surgery should be expected within 1-2 years after vitrectomy surgery.