Eye Cancer

On the basis of the origin of the cancer cells, eye cancer can be classified into primary and secondary. Primary intraocular cancer develops within the eye itself. The two most diagnosed primary intraocular cancers are Intraocular Melanoma in adults and Retinoblastoma in children. Secondary intraocular cancer or metastatic cancer stems from other parts of the body and gradually affects the eyes. It can arise from cancers of lung cancer and breast cancer. 

Eye melanoma generally doesn't have prominent signs and symptoms in the early stages. But later, signs and symptoms of eye melanoma can include:

1. Eye floaters or Eye flashes

2. Pupillary changes at the centre of the eye

3. Poor or blurry vision in one eye

4. Loss of peripheral vision

5. Bulging of one or both eyes

6. Presence of a dark mole near the white part of the eye

The exact cause behind the majority of eye cancers is not known, and a lot of research is being conducted very often to learn more about the causes.

Certain changes in the DNA inside cells can cause the cells to become cancerous. DNA can also influence the risk of developing certain diseases. Some genes control the cells growth, the division into new cells, and death.

Cancers can mainly be caused by DNA changes that turn on oncogenes or turn off tumour suppressor genes.

To diagnose eye melanoma, the doctor may perform the following:

1. Eye examination. The doctor will examine the eye for the presence of any enlarged blood vessels, which indicates a tumour inside the eye by means of Binocular indirect ophthalmoscopy and another method called Slit-lamp biomicroscopy.
   
   

2. Eye ultrasound. An eye ultrasound makes use of high-frequency sound waves to generate images of the eye. The transducer is placed on the closed eyelid or on the front surface of the eye.
   
   

3. Angiogram. During this procedure, a coloured dye is being injected into a vein in the arm area, which travels to the blood vessels in the eye. A camera equipped with special filters to detect the dye takes pictures every few seconds for several minutes.
   
   

4. Optical coherence tomography. The imaging test creates pictures of a few areas of the uveal tract and retina. A tissue sample is removed for testing by inserting a thin needle into the eye and used to extract tissue which is tested in a laboratory to determine whether it carries eye melanoma cells. An eye biopsy isn't usually required to diagnose eye melanoma.

The doctor may recommend certain additional tests and procedures to determine whether the Melanoma has spread (metastasized) to other parts of the body. Tests may include:

1. Blood tests to measure liver function

2. Chest X-ray

3. Computerized tomography (CT) scan

4. Magnetic resonance imaging (MRI) scan

5. Abdominal ultrasound

6. Positron emission tomography (PET) scan

The treatment options depend mainly on the location and size of the eye melanoma, as well as the overall health condition of the patient.

Treatment of small eye melanomas

They do not require instant treatment. If the Melanoma is relatively small and isn't progressing, the doctor opts to wait and watch for signs of any growth. If the Melanoma begins to grow or creates further complications, the following treatments can be given:

Radiation therapy

Radiation therapy is provided for eye melanomas that are of small to medium size and are usually given to the tumour by placing a radioactive plaque on the eye, directly over the site of a tumour in a procedure called brachytherapy. This type of radiation therapy often lasts over several days.

Laser treatment

Laser treatment can be given to kill the melanoma cells. Thermotherapy, which uses an infrared laser, is sometimes given in combination with radiation therapy and proves highly effective in the treatment of melanomas.

Photodynamic therapy

It combines medications with a particular wavelength of light, making the cancer cells accessible to light, thereby damaging the vessels and the cells that constitute the Melanoma of the eye. Photodynamic therapy is given in smaller tumours, as it is more potent in treating them rather than larger cancers.

Cold treatments

Cryotherapy may be used to eradicate melanoma cells in some small eye melanomas, but this treatment isn't commonly used.

Surgical options comprise of:

1. Iridectomy: Removal of some part of the iris
2. Iridocyclectomy: Removal of part of the iris and ciliary body
3. Sclerouvectomy/endoresection: Removal of the choroidal tumour
4. Enucleation: Removal of the eye

In certain cases, surgery may also be used to place a radioactive disc for internal radiation therapy, also called brachytherapy.

Risk factors include:

1. Light eye colour. People with blue eyes or green eyes are more prone to Melanoma of the eye.
2. Being white. White people are at a higher risk of eye melanoma than individuals of other race groups.
3. Age. The probability of eye melanoma increases with age.
4. Certain inherited skin disorders. Few conditions like dysplastic nevus syndrome and Ocular melanocytosis have an increased chance of exhibiting eye melanoma.
5. Exposure to ultraviolet (UV) light. This may result in the risk of developing this condition.
6. Certain genetic mutations.

Complications of eye melanoma are as follows:

1. Increasing pressure within the eye (glaucoma).
2. Loss of vision.
3. Eye melanoma spreads outside of the eye and to distant areas of the body, including the liver, lungs, and bones.

1. For Your EYES - Prevention Is Better Than Cure
2. Pressure Inside the Eyes Can Damage the Optic Nerve!

Reviewed by Dr. Rohit Nayyar, Director, Cancer Care / Oncology, Head & Neck Oncology, Surgical Oncology on 12-May-2022