The incidence of eye cancers in the Indian population is low (ranging from 0.3-0.4 percent), and statistics show that 70-80 % cases are seen in adults, and the rest in children. Based on the site of origin of the disease process, eye cancers can be primary (that is, starting within the eye) or metastatic (that is, spreading to the eye from another organ like breast or lung). Like all other cancers, early detection is key to controlling the disease but is often missed because the clinical presentation of these cancers can be variable, and the patient usually ignores the signs and symptoms.
What are the types of eye cancers?
The different types of primary eye cancers include:
- Eye or intraocular melanoma: conjunctival, choroidal
- Squamous cell carcinoma
- Lymphoma or Primary intraocular lymphoma: often associated with lymphoma in the brain ( called primary central nervous system (CNS) lymphomas, usually bilateral)
- Retinoblastoma – more commonly seen in children, especially in the 0-4 years age group. The most common secondaries, or metastatic tumors, in the eye are from breast and lung cancers.
What are the signs and symptoms of eye cancers?
Eye cancers are a diverse entity with several presentations. Most of the symptoms are seemingly innocuous and consequently ignored by patients in the initial stages. The signs and symptoms listed below may be due to several other benign conditions, and cancer can usually only be detected by a comprehensive eye examination by your eye doctor.
The commonly reported symptoms of eye cancer include:
- Flashes of light, or floaters
- Blurred vision, haloes, and shadows around images, especially of bright light
- A dark nevus or mole on the white part of the eye that increases in size get “angry” looking blood vessels around it, or bleeds
- The decrease in vision may be associated with pain
- Bulging of one eye, or both, called proptosis
- A lump or tumor on your eyelid or in your eye that’s increasing in size, getting blood vessels
- Change in color of the iris
- White reflex in the pupil
What are the danger signs to watch out for, in children, for retinoblastoma?
Because retinoblastoma mostly affects infants and small children, symptoms are rarely reported, and it is up to the parents to notice any changes in the eye of the infant or child. Signs to look out for are:
- White color in the center of the eye: The center of your eye, the pupil, is usually darker than the surrounding iris. A white discoloration, especially in children, requires immediate attention, especially if associated with a squint in the same eye. This white reflex is noted especially when using a flash for taking pictures, unlike the red eye which is often picked up in pictures, or when a torch is shone in the eye.
- Suddenly, the eyes appear to be looking in different directions. Any acquired squint in small children must be checked by an eye doctor.
- Eye redness and swelling, excessive tearing
How is the staging of eye tumors done?
The clinical stage is determined from the results of eye exams, radiological tests (ultrasound, CT, and MRI scan) as well as pathological tests after a biopsy. The doctor may also suggest a PET Scan, to look for secondary tumors, or for primary cancer in case suspecting metastatic cancer. Doctors usually follow standardized international staging systems like the American Joint Committee on Cancer (AJCC) TNM system and the system used by the Collaborative Ocular Melanoma Study (COMS) group, to plan treatment, provide the patients with prognosis and collaborate with colleagues in various other disciplines like oncology, radiation medicine and oncosurgery for patient care.
What is the treatment for eye tumors?
The three basic modalities of treatment of eye cancers include surgery, radiotherapy, and chemotherapy. The procedure is decided by a multidisciplinary team and customized to the needs of the individual patient. It depends on several factors. These include:
- The type of eye cancer, it’s grade, which determines how aggressive it is, and its malignant potential
- The rate of tumor growth, and its size and stage at presentation, the extent of spread locally and at distant sites
- The site of the tumor, whether it is on the eyelid, conjunctiva or within the eye or spread more extensively
- General health and coexisting diseases in the patient, age at presentation and patient choice
The ophthalmologists taking care of these eye cancers work on the following fundamental principles:
- Saving the life of the patient is paramount
- Saving the sight, as much as possible, is the most important
- Preserving the functional and structural integrity of the eye
- Preserving the cosmetic appearance of the eyeball and surrounding areas
Based on this, the various options your eye surgeon can choose from, are listed below.
- Laser therapy: It directs a laser beam to destroy the tumor cells locally.
- Plaque therapy or brachytherapy: In which a plate impregnated with the therapeutic agent is used to direct the treatment to the specific location alone, minimizing damage to surrounding tissue.
- Radiotherapy: Delivers radiation that destroys the tumor cells, without affecting the surrounding delicate tissues, and several modern radiation treatments, such as proton therapy, are proven to have a better track record in accuracy in dose delivery, minimizing collateral damage to the surrounding areas.
- Limited resection: That is, removal of the area of the eye that is affected by cancer. For example, iridectomy, choroidectomy, eyelid resection, etc.
- Enucleation: Consists of removal of the eyeball, in which the eyelids and eye muscles are not removed. Later, the eye surgeon can fit a prosthesis, an artificial eye for better cosmetic results.
- Evisceration: Consists of partial removal of the eye contents, leaving the sclera or the white part of the eye behind. Both enucleation and evisceration require a prosthetic eye, which can only be a cosmetic eye, with no vision.
- Exenteration: Is an extensive surgery, which involves removal of the eye, all orbital contents, and A specially designed prosthesis can later be fitted to preserve the appearance of the face.
- Chemotherapy: Involves the use of special drugs which may be administered orally or by injection to fight the cancer cells.