When they hear the word “cancer,” most people may think of cancer of parts of the body such as breasts, lungs, colon, brain, bones, and prostate. But did you know that the eyes are also at risk of cancers? The most serious can be Intraocular Cancers, cancers that occur inside (intra) the eye.
Several eye cancers are more common, such as cancers of the eyelids like squamous cell carcinoma on the conjunctiva, which is the eye’s surface. There are also squamous cell carcinomas, which are light related inside the eye. The most common tumor is a mole or a Nevus. About one in six people will have a Nevus inside of their eye.
Intraocular cancers can affect every tissue inside of the eye and give rise to a tumor. Some tumors are benign, and some can be malignant. For example, the iris, the colored part of the eye, can develop a Nevus, a benign tumor, or melanoma, a malignant tumor.
The retina in the back of the eye can develop a retinal blastoma, a cancer seen in children. The retina layer is called the choroid, a vascular layer, and, in that layer, the eyes can get moles. Also, there is choroidal melanoma and several other cancers that you can get inside the eye.
There are two ways intraocular cancers can occur:
- Primary intraocular cancers – cancer that starts in the eye
- Secondary intraocular cancers – begins elsewhere and spreads to the eye
In adults, the most common primary intraocular cancers are:
Ocular Melanoma
Ocular melanoma is the second most common type of melanoma after cutaneous melanoma, a form of cancer that starts in the skin’s pigment-producing cells.
It arises from melanocytes (cells that produce melanin in the skin) situated in the conjunctiva, the clear, thin membrane that covers part of the front surface of the eye and the inner surface of the eyelids. Ocular melanoma can also form in the uveal tract, the middle layer of the eye’s wall.
Although rare, it can also arise from melanocytes located in the orbit (the space within the skull that holds the eye. The uvea is the most frequent site of origin of ocular melanomas and comprises 82.5% of all cases, while conjunctival melanoma is far less common.
The majority of ocular melanomas are primary; however, metastatic melanoma from the primary cutaneous site (the skin) can also occur in the ocular region. It accounts for less than 5% of all metastases to the eye orbit. Your eyes also have melanin-producing cells that can develop melanoma.
Symptoms of Ocular Melanoma
You may have ocular melanoma but have no symptoms. Signs that may reveal this intraocular cancer include:
- Your pupil has a change of shape
- A dark spot growing on the iris
- Floaters (flashes or spots in your vision)
- Loss of peripheral vision
- Low or blurry vision in one eye
Non-Hodgkin lymphoma ocular cancer
Our immune system is a sophisticated network of immune cells that comprises white blood cells called lymphocytes. Non-Hodgkin lymphomas (NHLs) are a disparate group of malignancies (tumors composed of cancer cells) originating from lymphocytes.
When these malignancies develop in the eye, it is referred to as lymphoma ocular cancer. It is the most common type of malignant eye tumor.
There are two primary types of lymphatic cells: B-cells and T-cells. When lymphoma develops in the eye, it is called primary intraocular lymphoma (PIOL). 90% of the time, it is the lymphatic B-cells causing cancer. T-cell non-Hodgkin lymphoma accounts for 10 percent of all cases.
PIOL can develop in the retina, the vitreous, or in the optic nerve. About 80 percent of patients who have PIOL develop it in both eyes. The majority of those who develop primary intraocular lymphoma are elderly. Others may have immune system diseases such as rheumatoid arthritis.
Lymphoma frequently spreads to the liver, bone marrow, or lungs; however, it can move to the eye to become the category of secondary intraocular cancers.
Symptoms of Non-Hodgkin lymphoma ocular cancer
There are several lymphoma ocular cancer symptoms. Most common include:
- Blurred vision
- Decline or loss of vision
- Eye pain
- Floaters
- Increased sensitivity to light
- Redness or swelling in the eye
In children, the most common primary intraocular cancers are:
Retinoblastoma
Retinoblastoma (Rb) is a very rare eye tumor of childhood that arises in the retina and represents the most common intraocular cancer of infancy and childhood. The incidence of retinoblastoma in the United States is around 1.2 cases per 100,000 children aged four years or younger.
Retinoblastoma may have signs and symptoms that are noticeable, but that is often not the case. There are no commonly recommended screening tests for retinoblastoma.
Retinoblastoma can be detected by light reflecting off the tumor, causing the pupil to appear white, called “cat’s eye reflex” (leukocoria). Also, the eyes may be misaligned, appearing crossed (strabismus).
Rb may occur in one eye or both eyes. Either one of the child’s eyes may become red and painful. Retinoblastoma can also cause a rise in the pressure (glaucoma) in the eye, potentially causing damage to the optic nerve.
With advances in therapy, the likelihood of salvaging vision in promptly diagnosed cases and survival has risen radically during the last two decades.
Medulloepithelioma
Intraocular Medulloepithelioma is an even rarer eye tumor than retinoblastoma. Rb is characterized by a white, gray, or yellow-colored cystic mass that arises from the ciliary body or occasionally from the optic nerve, optic disc, retina, or iris.
Typically, it has a benign clinical course with a good prognosis and generally presents with childhood-onset of poor vision and pain, glaucoma, and/or cataract.
Intraocular cancer treatment
Intraocular tumors are in very delicate places in the eye. There must be early diagnosis and treatment of the patient to save their vision, eye, and possibly life in the most severe cases.
Treatment varies by the type and how advanced it is. It may include surgery, radiation therapy, or alternative treatment options. Routine annual examinations of the back of the eye are recommended after 50, which is when intraocular cancer commonly starts to appear.
