What are enucleation and evisceration?
Enucleation is the surgical removal of the entire eye. Evisceration is the surgical removal of the contents of the eye, leaving the white part of the eye and the eye muscles intact.
Why is enucleation or evisceration necessary?
Removal of an eye may be required following a severe injury, to control pain in a blind eye, to treat some intraocular tumors, to alleviate a severe infection inside the eye, or for cosmetic improvement of a disfigured eye.
Why choose one procedure over another?
Enucleation is the procedure of choice if the eye is being removed to treat an intraocular tumor, or to try to reduce the risk of developing a severe autoimmune condition called sympathetic ophthalmia following trauma. In most other situations, an evisceration is preferred. Dr Mavrikakis will help you determine which surgery is most appropriate for your condition.
What is sympathetic ophthalmia?
Sympathetic ophthalmia is an exceptionally rare form of inflammation that can occur in the healthy eye any time after an open eye injury or an operation on the other eye that exposes the uvea, the pigmented layer of the eye. This occurs because the exposed contents of an injured eye can activate the body’s immune system against the same tissues in the healthy eye. Although treatable in the vast majority of patients, such an inflammatory problem can rarely lead to loss of sight in the good eye. The removal of an eye using the evisceration method (but not an enucleation) carries this theoretical risk of such an inflammation. It should be noted however that such eyes have usually had previous injury or surgery, and the other normal eye is therefore already at risk, even before the eye is removed. The true likelihood of developing sympathetic ophthalmia in the good eye after an evisceration is very difficult to determine, but is considered to be in the order of 1: 50,000. However, sympathetic ophthalmia is treatable, and overall many more eviscerations are now performed than enucleations for the reasons outlined above.
How is the surgery performed?
Both surgeries are usually performed in the operating room under general anesthesia, although they can be completed safely using local anesthesia with sedation. After enucleation or evisceration, most of the lost volume is replaced by an implant placed in the eye socket. The implant is a usually a sphere made of silicone rubber, polyethylene, hydroxyapatite, or alumina, and is covered by the patient’s own tissue. In most cases, the eye muscles are attached to the implant following enucleation, in order to preserve eye movement. For some patients who are not suitable for such an implant, a dermis fat graft is used instead. This is taken from the abdomen or the upper outer quadrant of the buttock area. Several weeks after surgery, an artificial eye, or prosthesis, is made by an ocularist. The front surface of the artificial eye is custom painted to match the patient’s other eye. The back surface is custom molded to fit exactly in the eye socket for maximum comfort and movement. The prosthesis is easily removable, and may be removed as needed for cleaning. Most patients sleep with the prosthesis in place. Dr Mavrikakis may offer the option of placement of a motility peg. This peg is inserted into the implanted sphere, usually several months after surgery. The front of the peg fits into a small concavity on the back surface of the prosthesis. This fixes the implant directly to the prosthesis to try to achieve better movement. This procedure is associated with potential complications, and should be discussed with Dr Mavrikakis.
What are the risks and complications?
Short-term risks for this surgery, as with any surgery, include bleeding and infection. Longer-range complications include discharge, socket irritation, and exposure of the implant. As with any medical procedure, there may be other inherent risks that should be discussed with Dr Mavrikakis.
What is the post-operative care?
Evisceration and enucleation are usually day case procedures and thus patients can be discharged a few hours after their surgery. You may be asked to take medications after surgery such as antibiotics, steroids, or pain-relievers. Patients may wear a patch after surgery for several days to weeks. Continued follow-up is important as the tissues in the socket may atrophy (shrink) with time. This loss of volume may lead to eyelid laxity or socket changes that may affect the fit of the prosthesis. Careful monitoring of the socket and prosthesis by the surgeon and the ocularist will help keep the socket healthy, and will allow for early detection of any changes that may require further treatment.
How will I look after surgery, and when can I wear an artificial eye (prosthesis)?
During the healing phase after surgery, the patient wears a clear plastic shell (a surgical conformer) inserted behind the eyelids to maintain the shape of the socket. During this interval any socket inflammation and swelling gradually resolve. The artificial eye is then made, using the color and characteristics of the fellow normal eye as a template. It is usually fitted as soon as the socket has completely healed. This can take 2-3 months. It is important that the artificial eye is not fitted too soon as this can disrupt the wound and predispose to exposure of the buried implant.
The artificial eye, or ocular prosthesis, is designed and fitted by ocularists or ocular prosthetists. They have considerable experience in both making and fitting an artificial eye, and monitoring the subsequent fit and health of the eye socket.
What problems can occur with wearing an artificial eye (prosthesis)?
The artificial eye should only be removed very infrequently for cleaning. It is wise to use artificial tears 3-4 times a day and at bedtime to keep the surface pristine. The artificial eye should be checked and polished at least once a year by an ocularist and usually needs replacing after 5-7 years. The socket will be checked at the same time to ensure that there are no problems. With good attention to socket and eyelid hygiene, artificial eye problems such as discharge and discomfort are generally prevented.