Introduction
According to the National Cancer Institute, the most common cancer type is breast cancer, with the next being lung and prostate cancer. However, the eyes are also at risk of cancer.
When cancer spreads to the eye – Cancer can spread anywhere in the body through the bloodstream or the lymph system and spread to the eyes. There are several cancers of the eye’s surface, like squamous cell carcinoma on the conjunctiva, the eyelids. However, the most serious is Intraocular Cancer, cancer inside the eye.
Intraocular cancers can originate in the eye (primary) or start elsewhere (secondary) and spread to the eye. Secondary Intraocular Cancers commonly spread from lung cancer in men and breast cancer in women, and least frequently from the kidney, thyroid, prostate, and digestive tract. Blood cell cancers like lymphoma and leukemia additionally may spread to the eyes.
Intraocular cancer can develop in each tissue inside the eye. When cancer develops in the Uveal from melanocytes, the cells that create pigments, it is called Intraocular (Uveal) Melanoma.
The eye’s uveal tract consists of the iris, ciliary body, and choroid and contains a melanocyte population. Uveal melanomas develop from melanocytes in the stroma of the choroid, ciliary body, or iris. Ocular tumors can occur practically anywhere in the eye. They can appear in the iris, the ciliary body, the choroid, the retina, and the retinal pigment epithelium.
Most often, however, tumors start in the part of the uvea called the choroid. The choroid is the vascular part of the human eye between the retina and sclera. Though accurate measurements of the choroidal blood flow are complex, it is known that the choroid is one of the most vascular tissues in the body and its blood flow is one of the highest.
Previously we talked about how cancer can spread throughout the body via the bloodstream or the lymph system. When cancer starts in the choroid, it can be more likely to spread to other parts of the body than intraocular melanoma of the iris, for example.
Choroid cells also have the same kind of pigment as skin cells leading to skin cancer possibly spreading to the eyes. These vascular and melanocyte factors make Intraocular (Uveal) Melanoma a feared condition because it is potentially lethal.
Intraocular melanoma is the most common eye cancer in adults. Intraocular cancer often goes undetected unless the patient’s vision is affected, the cancer is visible, or the eye is pushed forward. The good news is that while a common cancer of the eye, it is a rare cancer overall.
Incidence and distribution
Uveal melanomas are found in the iris and the ciliary body, but the majority of cases in the choroid. Metastatic tumors (secondary tumors that break away from primary cancer) of the choroid are the most common intraocular malignancy but only slightly more common than choroidal melanoma.
Choroidal melanoma is the most common primary intraocular malignancy in adults. It has an estimated annual incidence in the United States is approximately 4.3 new cases per million people. The incidence in males is higher than in women, with 4.9 cases per million and women at 3.7 cases per million.
Intraocular (Uveal) Melanoma is diagnosed mostly after 50, with a progressively rising incidence rate peaking around the age of 70. Since the early 1970s, the age-adjusted incidence of this cancer has remained stable. Source: National Cancer Institute
Risk factors for intraocular melanoma include:
- Having a fair complexion that freckles and burns easily, does not tan, or tans poorly.
- Blue or green or other light-colored eyes
- Being above the age of 50
- Being Caucasian
Diagnosis and Symptoms
Most of the patients with intraocular cancers have no symptoms, and the tumor is discovered on ophthalmic examination. On ophthalmoscopy, also called fundoscopy, choroidal melanoma usually looks like a dome-shaped tumor with variable pigmentation and sometimes with serous (watery) detachment.
Tumors are generally pigmented, but one-fourth are relatively non-pigmented. Symptomatic patients may have distorted or reduced vision when the tumor develops next to or in the macula. Vision field defects may occur due to exudative retinal detachment (when fluid under separates your retina) or from the tumor.
Exudative retinal detachments are usually seen with tumors more than 4 mm thick. Flashes or floaters may occur due to retinal diseases like posterior vitreous detachment. Pain is rare but occurs when there is angle-closure or neovascular glaucoma.
Schedule an appointment with your eye doctor if you have any of the following signs or symptoms:
- The position of your eyeball in the eye socket changes.
- Changes in vision or blurred vision
- Unusual floaters or flashes of light
- A dark spot on the iris
- Your pupil changes size or shape
*Note that these symptoms are common to many eye conditions, so don’t panic. Regular eye exams are essential no matter what symptoms may manifest during your life.
Examination methods
Careful examination by a highly qualified ophthalmologist or retinal specialist is required to establish the presence of intraocular melanoma. A retinal specialist may use various tests to diagnose patients for intraocular melanoma and other eye cancers. In addition to initial physical exams and reviewing health history, they will use one or more of these ophthalmic exam tests:
Dilated pupil eye exam – Dilation of the pupil, is a vital part of a comprehensive eye exam seeking to diagnose any ocular condition or disease. It is purposefully done to increase the pupil’s size so an ophthalmologist can thoroughly examine your eyes’ inner workings and conditions. With the pupil open wider, the eye doctor can use noninvasive diagnostic imaging tools such as:
- Ophthalmoscopy is also called a fundoscopic exam because it allows the eye doctor to see the fundus, the back of your eye, the retina, optic disc, choroid, and blood vessels.
- Slit-lamp biomicroscopy – a diagnostic tool that uses a bright light and a microscope to examine your eyes microscopically
- Fluorescein angiography – to exam the retina and choroid, the retinal specialist injects a fluorescent dye in the bloodstream so blood vessels can be photographed for close examination.
- Ocular coherence tomography – provides high-resolution 3D dimensional cross-sectional pictures of the retina.
Treatment options for Intraocular (Uveal) Melanoma
At times, a specific treatment modality may not be recommended. However, a regular appointment to check on the tumor must be made (watchful waiting). If the condition worsens, then a specific treatment will be prescribed.
If the doctor advises treatment, it may consist of one or more of the following:
- Laser Therapy
- Cryotherapy, freezing the tumor
- Radiation
- Chemotherapy
This can not be emphasized enough; if you have any symptoms that cause you to think you may have intraocular melanoma, please schedule an appointment with Arizona Retinal Specialists immediately. Early detection and effective treatment are the key to battling this cancer.
We are eminently qualified to diagnose and treat advanced conditions such as intraocular melanoma. Please schedule an appointment with us now.
