Enucleation, Eye Health Article

Definition

Enucleation is the surgical removal of the eyeball that leaves the eye muscles and remaining orbital contents intact.

Purpose

Enucleation is performed to remove large-sized eye tumors or as a result of traumatic injury when the eye cannot be preserved. In the case of tumors, the amount of radiation required to destroy a tumor of the eye may be too intense for the eye to bear. Within months to years, many patients who are treated with radiation for large ocular melanomas lose vision, develop glaucoma, and eventually have to undergo enucleation.

The two types of eye tumors that may require enucleation are:

• Intraocular eye melanoma. This is a rare form of cancer in which malignant cells are found in the part of the eye called the uvea, which contains cells called melanocytes that house pigments. When the melanocytes become cancerous, the cancer is called a melanoma. If the tumor reaches the iris and begins to grow, or if there are symptoms, enucleation may be indicated.
• Retinoblastoma. Retinoblastoma is a malignant tumor of the retina. The retina is the thin layer of tissue that lines the back of the eye; it senses light and forms images. If the cancer occurs in one eye, treatment may consist of enucleation for large tumors when there is no expectation that useful vision can be preserved. If there is cancer in both eyes, treatment may involve enucleation of the eye with the larger tumor, and radiation therapy for the other eye.

Demographics

Data from the U.S. National Center for Health Statistics estimate that nearly 2.4 million eye injuries occur in the United States annually. This report calculated that nearly one million Americans have permanent significant visual impairment due to injury, with more than 75% of these individuals being blind in one eye. Eye injury is a leading cause of monocular blindness in the United States, and is second only to cataract as the most common cause of visual impairment. While no segment of the population escapes the risk of eye injury, the victims are more likely to be young. The majority of all eye injuries occur in persons under thirty years of age. Trauma is considered the most common cause of enucleation in children over three years of age.

For the year 2000, Texas demographics for cancer of the eye and orbit were fewer than five per 100,000. According to the Nilt, there are about 2,200 cases of eye cancer diagnosed in the United States each year.