Enucleation is a surgical procedure involving the complete removal of an entire eye. This intervention is considered when other treatments are no longer effective or suitable for preserving the eye’s health or function. It can lead to improved comfort and health outcomes for patients.
What is Enucleation
Enucleation is the surgical removal of the entire eyeball, including its internal contents and a section of the optic nerve. This procedure leaves the eyelids and surrounding orbital tissues, such as the eye muscles, intact within the eye socket. The goal is to remove the diseased or damaged eye while preserving surrounding structures for a prosthetic eye.
Reasons for Enucleation
Enucleation is often a measure of last resort, undertaken for specific medical conditions. A primary reason is severe eye trauma, especially when an injury leads to irreversible damage and vision loss, or when there is a risk of sympathetic ophthalmia, an autoimmune condition affecting the healthy eye. Certain types of eye cancer, such as retinoblastoma or intraocular melanoma, frequently necessitate enucleation to prevent disease spread. The procedure also addresses eyes that are blind and cause uncontrollable pain, or those with severe infections like endophthalmitis that do not respond to other treatments. Additionally, enucleation may be performed for significant disfigurement of a blind eye, improving cosmetic appearance and relieving discomfort.
The Enucleation Procedure
The enucleation procedure typically begins with anesthesia, often general, though local anesthesia with sedation can also be used. The surgeon makes an incision around the conjunctiva, the clear membrane covering the white part of the eye. The eye muscles, which control eye movement, are then detached from the globe.
Following muscle detachment, the optic nerve is clamped and severed. The entire eyeball is removed from the eye socket. An orbital implant is usually inserted to maintain the natural shape of the eye socket and support a future prosthetic eye. This implant is placed within the muscle cone behind the conjunctiva. The eye muscles may be attached to the implant to allow for some movement of the prosthetic eye.
The patient’s own tissues, specifically the conjunctiva and Tenon’s capsule, are then closed over the implant using absorbable sutures. A temporary conformer, a clear plastic shell, is often placed behind the eyelids to maintain the shape of the socket during the initial healing phase.
Life After Enucleation
Following enucleation, a pressure dressing is applied to the eye socket for several days to reduce swelling and promote healing. Patients may experience mild discomfort, bruising, and some pink or watery drainage, which typically subsides within a few weeks. Pain is usually managed with over-the-counter medication, and a topical antibiotic and steroid ointment may be prescribed to aid healing.
Approximately 4 to 8 weeks after surgery, once initial healing has occurred, a specialist called an ocularist will fit the patient for a custom-made prosthetic eye. This ocular prosthesis is designed to match the color, shape, and luster of the remaining eye, sitting behind the eyelids and in front of the orbital implant. While the prosthesis does not restore vision, it significantly improves the cosmetic appearance and can move to some extent due to the attachment of the eye muscles to the underlying implant. Adapting to monocular vision involves adjusting to changes in depth perception and a reduced field of peripheral vision on the side of the removed eye. Over time, the brain learns to compensate for these changes, and individuals can resume most daily activities, including driving, with proper adaptation.
Enucleation Versus Other Eye Surgeries
Enucleation is distinct from other eye removal procedures. Evisceration involves removing the eye’s internal contents, leaving the outer white shell (sclera) and eye muscles intact. This procedure is less invasive than enucleation and may be chosen for painful blind eyes or severe infections when an intraocular tumor is not suspected.
In contrast, exenteration is a more extensive surgery that involves removing the entire eyeball along with surrounding orbital tissues, including fat, muscles, and sometimes the eyelids. Exenteration is typically reserved for aggressive cancers that have spread beyond the eye into the surrounding orbital structures. The choice between these procedures depends on the underlying medical condition, aiming for the best possible health and cosmetic outcome.