Enucleation involves first releasing the extraocular muscles from the sclera, then removing the globe. Enucleation allows for complete histologic examination of the eye and optic nerve. It reduces the concern that surgery might contribute to the risk of sympathetic ophthalmia (discussed below) in the fellow eye. Enucleation is the procedure of choice if the nature of the intraocular pathology is unknown or if an ocular tumor is suspected in an eye with no view of the posterior pole.
Enucleation is indicated for primary intraocular malignancies that are not amenable to alternative types of therapy. The ocular tumors most commonly requiring enucleation are retinoblastoma and choroidal melanoma. When enucleation is performed on an eye with an intraocular tumor, the surgeon must take care to avoid penetrating the globe during surgery and to handle the globe gently to minimize the theoretical risk of disseminating tumor cells. In cases of suspected retinoblastoma, removing a long segment of optic nerve with the enucleation specimen increases the chance of complete resection of the tumor. Blind eyes with opaque media should be suspected of harboring an occult neoplasm unless another cause of ocular disease can be surmised. Ultrasonography is useful in evaluating and planning proper management of these eyes.
In severely traumatized eyes, early enucleation may be considered if the risk of sympathetic ophthalmia and harm to the remaining eye is judged to be greater than the likelihood of recovering useful vision in the traumatized eye. Sympathetic ophthalmia is thought to be a delayed hypersensitivity immune response to the uveal antigens. Enucleation with complete removal of the uveal pigment may be beneficial in preventing this subsequent immune response. The yearly incidence of sympathetic ophthalmia is estimated to be 0.03 cases per 100,000. The condition has been reported to occur from 9 days to 50 years after corneoscleral perforation. The infrequency of sympathetic ophthalmia, coupled with improved medical therapy for uveitis, has made early enucleation strictly for prophylaxis a debatable practice. (See BCSC Section 9, Uveitis and Ocular Inflammation, for additional information.)
Painful eyes without useful vision can be managed with enucleation or evisceration. Patients with end-stage neovascular glaucoma, chronic uveitis, or previously traumatized blind eyes can obtain dramatic relief from discomfort and improved cosmesis with either procedure. Enucleation can be performed satisfactorily under local or general anesthesia; however, most patients prefer general or monitored anesthesia when an eye is removed. For debilitated patients unable to undergo surgery and rehabilitation, retrobulbar injection of ethanol may provide adequate pain relief. Serious complications associated with retrobulbar injections of ethanol include chronic orbital inflammation, fibrosis, and pain.
For nonpainful, disfigured eyes, it is generally advisable to consider a trial of a cosmetic scleral shell prior to removal of the eye. If tolerated, scleral shells can provide excellent cosmesis and motility.
Tan XL, Seen S, Dutta Majumder P, et al. Analysis of 130 cases of sympathetic ophthalmia—a retrospective multicenter case series. Ocul Immunol Inflamm. 2018:1–8.
Enucleation in childhood
Enucleation in early childhood, as well as congenital anophthalmia or microphthalmia, may lead to underdevelopment of the involved bony orbit with secondary facial and eyelid asymmetry. Orbital soft-tissue volume is a critical determinant of orbital bone growth. Thus, for an anophthalmic socket in a young child, the surgeon aims to select an implant that maximally replaces the lost orbital volume but exerts minimal tension on the wound.
In young children, autogenous dermis-fat grafts can be used successfully as primary anophthalmic implants. These grafts have been shown to grow along with the expanding orbit. The opposite effect has been observed in adults, in whom a loss of volume generally occurs when dermis-fat grafts are used as primary anophthalmic implants.
Quaranta-Leoni FM, Sposato S, Raglione P, Mastromarino A. Dermis-fat graft in children as primary and secondary orbital implant. Ophthalmic Plast Reconstr Surg. 2016;32(3):214–219.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.