Occasionally, a retinal detachment is complicated or severe, and cannot be treated adequately with either standard or scleral buckling surgery or pneumatic retinopexy. In such cases, vitreous surgery to reattach the retina may be necessary. Vitreous surgery is performed in an operating room under local or general anesthesia. The vitreous is removed, and therefore this procedure is called vitrectomy. The surgeon uses a fiberoptic light to illuminate the inside of the eye and other instruments inside the eye such as forceps and scissors to do the surgery. The vitreous is replaced during the operation with either clear fluid that is compatible with the eye, or with gas that completely fills the eye. Over time, the fluid (or gas) is absorbed by the eye and is replaced by the eye's own fluid; the eye does not replace the vitreous gel itself. The lack of vitreous gel does not affect the functioning of the eye.
The most common conditions requiring vitrectomy are retinal detachment in an eye that has had cataract surgery, vitreous hemorrhage with retinal detachment, proliferative vitreoretinopathy, giant retinal tear, diabetic retinopathy with vitreous hemorrhage, and/or traction retinal detachment, or epiretinal membrane (macular pucker).