Cancer can develop both in the eye and its surrounding tissues. The eye consists of the eyeball, the orbit and tissues around the eye like the eyelids and tear glands. Certain types of cancers like melanoma and retinoblastoma can originate in the eye itself, and different types of skin cancers can develop in the eyelids. Other types of cancer can spread from other parts of the body to the eye and the tissues of the orbit. Surgery, chemotherapy and radiation therapy can be used to treat these cancers depending on the location.
Statistics
The American Cancer Society estimates about 2,500 will be diagnosed with cancers of the eye and orbit in 2010. Eye cancers that originate primarily in the eye develop more often in people who are over the age of 50. The incidence of primary eye tumors has remained about the same for the past 25 years. Cancers of the eye and orbit that have spread from other parts of the body are actually more common than primary eye cancers.
Cancers of the Eyelids
According to MDAnderson.org, there are four main types of cancers that can develop in the eyelids; each comes from a different type of cell in the eyelid. Basal cell carcinoma originates from basal cells and can cause a significant amount of damage to the eyelid; however, these do not tend to metastasize. Squamous cell carcinomas are less common than basal cell carcinomas but can spread into the orbit and sinuses as noted by Eye Cancer Network. In some elderly people, the oil-producing glands of the eyelids can develop into malignant tumors; these sometimes look like styes on the eyelids. Melanomas---which develop from the pigmented cells in the eyelids---can develop on the eyelids as well but are the least common of the tumors.
Intraocular Cancers
There are several types of cancers that can begin in the eye itself. Melanoma can develop inside the eye and typically involves the pigmented layer of the eye---the iris, or the ciliary body that is the tissue that changes the size the pupil, and the choroid which is the layer of blood vessels under the retina. According to MDAnderson.org, the choroid is the most common spot for this type of cancer.
Intraocular lymphoma, which is another type of intraocular cancer and involves the cells of the immune system, is always the non-Hodgkin's type, according to the American Cancer Society. The most common intraocular cancer is retinoblastoma, which occurs in children; this cancer develops from cells in the retina.
Cancers of the Orbit
A muscle cancer, or rhabdomyosarcoma, which is the most common orbital malignant tumor in childhood, can occur within the eye socket. The tear or lacrimal glands can become malignant tumors as well. Other tissues inside of the orbit can develop into malignant cancers such as sarcomas, which are malignant tumors involving the connective tissue of the eye. However, cancers from any part of the body can spread to the orbit as metastases, according to the Academy of Ophthalmology.
Treatment
For most tumors involving the eyelid and the orbit, the first treatment is to surgically remove the tumor. If an eyelid tumor has expanded into nearby tissues, the surgeon may have to remove a larger area of tissue that may include the eye as noted by the Academy of Ophthalmology.
Cancers involving the eyeball can sometimes be treated with radiation therapy or surgical resection, depending on the location of the tumor. If the tumor is very large or expanding outside of the eyeball, the surgeon may remove the entire eyeball and put a prosthesis in its place. Systemic chemotherapy may be used to treat lymphoma of the eye or different types of cancer metastases.
