What is ocular oncology?
Ocular oncology involves the diagnosis and treatment of all tumors that occur in or around the eye— tumors of the eyelid, conjunctiva, intraocular structures and orbit.
Ocular tumors can range from harmless to potentially life-threatening. They may also cause vision loss or loss of the eye itself.
- Eye cancer survival rates depend on the type of tumor, and its size and location.
- The 5-year survival rate for people with eye cancer is 80-85%, depending on the stage of the cancer at diagnosis.
- 73% of people are diagnosed at an early stage.
Eye neoplasms (tumors)
Eye neoplasms are benign or malignant (cancerous) tumors that occur in or around the eye. Eye cancer is rare in comparison to other cancerous tumors. Benign tumors may also be called dermoid cysts.
Malignant tumors may be either rhabdomyosarcoma or retinoblastoma, and can be primary, starting within the eye, or secondary (metastatic), spreading to the eye from another organ. Most eye tumors are metastatic— usually starting in the breast, lung, bowel or prostate.
Two types of primary tumors develop within the eye itself— retinoblastoma in children and ocular melanoma in adults.
What is retinoblastoma?
Retinoblastoma is a cancer of the eye that begins in the retina, the eye’s light-sensitive tissue. It is a rare form of cancer, though the most common eye cancer that affects children under five years of age.
- Retinoblastoma diagnosis is rare— accounting for 2% of all childhood cancers.
- 1 in 15,000 children develop retinoblastoma— with approximately 9,000 new cases each year.
- Early detection enables a 95% cure rate.
Retinoblastoma generally occurs in one eye, though 25 percent of children will develop the cancer in both eyes.
Symptoms of retinoblastoma
As symptoms of retinoblastoma are not evident in its early stages, increasing pain and vision loss as the cancer progresses, become the primary signs that signal a problem.
Other signs include:
- White/yellow glow through pupil
- Eye pain
In some cases, parents are alerted to a problem when looking at photographs of their children. If a child’s eyes contain a white/yellow dot in the center of the pupil, instead of a red eye reflex, it can indicate a tumor.
Caution: To ensure that you do not cause unnecessary panic and anxiety, make sure to show your eye doctor any of the photos in question.
If you notice any changes in your child’s eyes or vision, or if your child complains of eye pain, it is crucial to call your child’s eye doctor as soon as possible. Be sure to inform your eye doctor if you have a family history of retinoblastoma.
What is ocular melanoma?
Ocular melanoma is a rare form of cancer that occurs in the pigment producing cells of your eyes. Ocular melanomas usually develop in the middle of the three layers of your eye, called the uvea. In rare cases, the melanoma can also develop on the conjunctiva.
Eye melanoma is difficult to detect because it does not cause any early signs or symptoms.
- Ocular melanoma most commonly affects adults 60 to 65 years of age.
- Ocular melanoma affects 1 in 5 million adults, worldwide.
What causes ocular melanoma?
Ocular melanoma develops when the DNA of the pigment cells of the eye develop errors that cause the cells to multiply uncontrollably. These mutated cells gather in or on the eye and form a melanoma.
The exact cause of this occurrence has yet to be discovered. However, it has been shown that certain people are at a higher risk.
Factors that may increase your risk of developing melanoma:
- Excessive exposure to natural or artificial UV rays
- Light-colored eyes (blue or green eyes)
- Older age
- Caucasian descent
- Inherited skin conditions causing abnormal moles
- Abnormal eyelid pigmentation
- Increased pigmentation on the uvea
- A mole in the eye or on the eye’s surface
Symptoms of ocular melanoma
Since most melanomas occur inside the eye, you may not know that you have a melanoma until symptoms present— usually as the cancer progresses.
Symptoms may include:
- Dark spot on the iris or conjunctiva
- Blurred or distorted vision
- Blind spot in peripheral vision
- Sensation of flashing lights
- Change in pupil shape
How are ocular tumors diagnosed?
Eye tumors are diagnosed by an experienced eye doctor, through a dilated eye exam.
Melanomas are distinctly different from moles— melanomas are more orange, thicker, and leak fluid. Your eye doctor will look for signs of melanoma through specialized diagnostic tests and equipment.
Ultrasound examination of the eye
An ultrasound of the eye is a procedure that uses high-energy sound waves (ultrasound) to produce an image of your inner eye. After numbing the eye with eye drops, your eye doctor will place a small probe on your eye to create the image. With an ultrasound examination, your eye doctor can look for abnormalities inside your eye, and calculate precise measurements of a tumor.
Fluorescein angiography (FA) is performed using a special camera that takes pictures of your retina. FA is usually done in your eye doctor’s office, and often takes less than 30 minutes.
During the procedure, your eye doctor will first dilate your eyes using eye drops to enable a clear view of the inner structures of your eye, specifically your retina. Then, a yellowish colored dye (fluorescein) is injected into a vein in your arm.
The dye travels through the bloodstream to your eye where it shines brightly. A special camera takes pictures as the dye travels through your retina to facilitate a precise location of the tumor, and enable an accurate treatment plan.
Autofluorescence imaging (AF) uses the naturally occurring fluorescence from the retina, and a special blue light to provide illumination, in order to determine retinal health. A healthy retina is seen as glowing, whereas a damaged retina will appear with dark spots or regions.
Optical coherence tomography
An optical coherence tomography scan (OCT scan) is a non-invasive, diagnostic tool that provides color-coded, cross sectional images of the retina, allowing for early detection and treatment of ocular cancer.
The OCT scan uses a laser (without radiation) to obtain higher resolution images of the layers of the retina and optic nerve to facilitate precise location of a tumor.
A biopsy is performed to obtain information about the tumor— and if it is likely to spread to other parts of the body. A biopsy may be performed for tumors on the conjunctiva. During a biopsy, your eye doctor will remove the growth from the surface of your eye (conjunctiva), and send the tissue to the laboratory for testing.
How is ocular cancer treated?
There are various ways to treat eye tumors— depending on the diagnosis, size, aggressiveness of the tumor, and your general health status.
Treatment options typically involve radiation and/or surgery that work to eliminate the cancer, but in doing so, can damage the vision in your eye.
Ocular melanoma radiation
Plaque radiation therapy is the most common type of radiation therapy used for ocular melanoma.
Radiation therapy uses various types of radiation to eliminate the tumor or prevent it from growing. Radioactive seeds are attached to a disk (plaque), and placed directly on the eye next to the tumor.
The plaque resembles a tiny bottle cap and is often made of gold— this protects nearby tissues from the radiation directed at the tumor. The plaque is held in place using temporary stitches, and is removed after five days.
Radiation therapy can also be delivered by a machine that directs a fine beam of radioactive particles toward the affected eye. This type of radiation therapy is often performed over the course of several days.
Ocular melanoma surgery
For smaller tumors, surgery may involve removing the tumor and some of the healthy tissue of the eye surrounding it.
Enucleation is a procedure in which the eye is removed and replaced with an implant. This surgery is performed for larger tumors, or those that cause eye pain, or involve the optic nerve. The implant is attached to the eye muscles to enable mobility.
Later on, after you have completely healed from the surgery, you will be fitted with a prosthesis, or a ‘fake eye’. This artificial eye can be custom painted to match your second eye.
Conjunctival melanoma treatment
Conjunctival melanoma treatment may involve chemotherapy eye drops, freezing treatment, or radiation.
Treatment of ocular tumors requires a team of specialists
When tumors develop inside and around the eye, a specialized team of doctors— including ophthalmologists, oncologists, radiation specialists, and surgeons are called upon to provide the best possible care for preservation of life, vision, and cosmetic appearance.
Excellent communication is also essential between the ophthalmologist, oncologist, radiation specialist, head & neck surgeon/ENT surgeon, pediatrician/internal medicine/hospitalist, support staff and nurses.
If you are experiencing any vision problems, or notice a change to the appearance of your eyes, make an appointment with your eye doctor as soon as possible.
Your eye doctor will conduct a series of tests to determine your ocular health and provide the best possible care for your individual needs.