Occasionally, a retinal detachment is so complicated and severe that it cannot be treated with either standard scleral buckling surgery or pneumatic retinopexy. In such cases, vitreous surgery to reattach the retina may be necessary. Vitreous surgery is performed in the hospital, often under 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 air that completely fills the eye. Over time, this fluid (or air) is absorbed by the eye and is replaced by the eye's own fluid; the eye does not replace the vitreous itself. The lack of vitreous does not affect the functioning of the eye.

Vitrectomy is required for retinal reattachment in a variety of conditions. For example, scar tissue may grow on the vitreous or surface of the retina and pull on the retina and detach it. Occasionally, something is in the vitreous, such as blood, that prevents the passage of light through the eye to the retina. The most common conditions requiring vitrectomy are vitreous hemorrhage with retinal detachment, proliferative vitreoretinopathy, giant retinal tears, diabetic retinopathy with vitreous hemorrhage and/or traction retinal detachment, epiretinal membranes (macular pucker), intraocular infection (endophthalmitis), trauma, and intraocular foreign body. In a vitrectomy, instruments are passed through the sclera into the vitreous cavity. A variety of instruments can be used to remove the vitreous gel and any scar tissue that may be growing on the surface of the retina. A laser probe can be inserted into the eye so that laser treatment can be done during surgery.

Vitrectomy can be combined with the placement of a scleral buckle. Occasionally, air, gas, or silicone oil is placed in the vitreous cavity. These materials hold the retina in place against the wall of the eye while the laser scars are taking hold. After this surgery, it may be important for the patient to maintain a cetain position of the head, which is often face-down (prone) position. Eventually, the air or gas is absorbed by the body and replaced by fluid produced by the eye. If silicone oil has been used, it usually must be removed at a later time with another surgical procedure. Vitreous surgery usually lasts one to two hours but, with very severe and dificult problems, may take many hours. Following surgery, the patient may experience some discomfort and a scratchy sensation in the eye, but significant pain is unusual. If it occurs, the surgeon should be told immediately.

Normal results

Vision is restored to useful levels in two-thirds of patients.