Cancer of the Eye
Eye cancer can be cancer of the eyeball itself (intraocular) or cancer of the surrounding tissue (extraocular) including the muscles, nerves and skin.
Intraocular cancer (of the eyeball itself) is very rare. There are several types.
Melanoma is the most common type of ocular cancer in adults, but is still very rare. Ninety percent of cases start in the choroid part of the uvea (middle layer of the eyeball), and the others start in the iris, which is also part of the uvea. When they develop in the iris they are visible, grow slowly, and rarely spread to other parts of the body.
Melanomas are made up of two types of cells. Spindle cells are elongated, and epithelioid cells are more round but have some straight edges. Most tumors will contain both types of cells. Epithelioid cells are more likely to spread.
- Non-Hodgkin’s Lymphoma
Most lymphomas start in the lymph nodes, but they can start in organs, including the eyes. Lymphomas normally develop in people who have compromised immune systems such as the elderly and those with AIDS.
Because it is the result of early development of the retina gone awry, retinoblastoma occurs in children, not adults. It is the most common form of eye cancer in children. Retinoblasts are cells which divide and fill the retina during early development. Eventually these cells should stop dividing and grow into mature retinal cells. When they do not stop dividing, they grow wildly, becoming cancerous.
Medulloepithelioma is very rare and is almost always found in small children. The tumors are painful and affect vision, but they rarely spread. When possible, just the tumor is removed from the eye, but in some cases the entire eye must be removed.
- Secondary Cancers
Sometimes cancer from other parts of the body will spread to the eye, usually breast or lung cancer. Typically when cancer spreads to the eye it affects the uvea, the eye’s middle layer between the retina and the sclera.
The most common forms of extraocular cancer are skin cancer of the eyelid and rhabdomyosarcoma. A rhabdomyoblast is an early type of muscle cell. A sarcoma is a cancerous tumor which arises in bone, cartilage, some muscle tissue, or connective tissue – as opposed to a carcinoma, which arises in epithelial tissue (membranes which line body cavities.
Rhabdomyosarcoma starts in the muscles that move the eye (the ciliary muscles) and usually occurs in children of about six years of age. These tumors grow very fast and push the eye forward. Some will enter the sinuses and destroy bone. They usually cannot be removed surgically and are therefore treated with radiation and/or chemotherapy.
If you suspect that you or your child may have cancer of the eye, contact an ophthalmologist today.