Ocular Oncolog

Ocular Oncology

Ocular oncology

Ocular oncology is the management of tumours in and around the eye, including the eyelids, orbit and lacrimal glands. Ocular tumours can occur in adults and children, and may affect one or both eyes.

Choroidal melanoma, choroidal haemangioma, retinoblastoma, eyelid tumour, conjunctival tumour and lymphoma/leukaemia are some of the common ocular cancers seen by ophthalmologists.

Choroidal Melanoma

Choroidal melanoma is a tumour occurring inside the eye, and is the most common primary intraocular tumour in adults.

Choroidal melanoma is a malignant tumour that can metastasize and spread to other parts of the body (mostly the liver). Patients with this disease are often around the age of 60 years. They do not recognize its presence until the tumour grows to a size that cause decreased vision, visual field loss, floaters, or photopsia (a ball of light travelling across the visual field 2-3 times a day). Regular eye examination through a dilated pupil is the best way of detecting the tumour.

The management of choroidal melanoma is tailored to the individual patient, taking into account; the size, location and extent of the tumour; the vision of that eye; the state of the other eye; the general health and age of the patient; and the patient’s wishes and fears.

Small suspicious tumours are usually watched closely for signs of growth before any treatment is started. Medium-sized tumours may be treated with radiotherapy or by removal of the eye. Large tumours are usually treated by removal of the eye. Tests are done to detect spreading of the tumour to other parts of the body.

Patients with choroidal melanoma undergoing evaluation and treatment at the Pretoria Eye Institute have access to the most advanced diagnostic testing and treatment modalities in South Africa.

Choroidal Haemangioma

Choroidal haemangioma is a tumour consisting of blood vessels. It is not a cancer and never metastasizes. The visual function may be affected when the haemangioma is located in the area of the central vision of the eye.

Most haemangiomas can be safely monitored by your eye doctor without the need of further treatment. Photographs are used to monitor evidence of growth, leakage or the need of treatment. Laser photocoagulation and external beam radiation are treatment options to decrease the amount of fluid leakage.

Choroidal Metastasis

Cancers from other parts of the body can spread in and around the eye. Breast cancer in women and lung cancer in men are the most common primary tumours to spread to the eye. Others include prostate, kidneys, thyroid, gastrointestinal tract cancers, and blood cell tumours (leukaemia and lymphoma). A team approach is followed in treating these patients, including eye specialist, medical oncologist, and radiation oncologist.

Treatment options include chemotherapy, radiation therapy and more rarely enucleation.

Choroidal Nevus

A choroidal nevus is like a freckle on the skin, but it occurs inside the eye. A nevus can become a malignant tumour and should be monitored regularly. Four to six monthly examinations by an ophthalmologist is needed to check for pigment and size changes. No treatment needed unless there is evidence of change.

Conjunctival Tumors

The conjunctiva is the outer layer covering the surface of the eye and inside of the eyelids. Malignant cancers include squamous cell carcinoma, melanoma and lymphoma. Squamous cell carcinomas invade the area around the eye into the orbit and sinuses, but rarely metastasize. They can start as a freckle (nevus) or can arise form an area of pigmentation. Lymphoma in the eye can be evidence of systemic lymphoma.

Most small conjunctival tumours can be monitored by photographs. Evidence of growth will lead to a full or partial biopsy. Melanoma and squamous cell carcinoma should be surgically removed. Other forms of therapy includes, cryotherapy (Freezing therapy) and chemotherapy eye drops.

Eyelid Tumors

Malignant skin cancers, inflammation, or benign cysts can all be found on the eyelid. Basal cell carcinoma is the most common eyelid tumour. The others include squamous cell carcinomas and sebaceous gland carcinomas.

Basal cell carcinomas can mostly be removed surgically. Untreated it grows around the eye, into the orbit and sinuses. To determine whether a tumour is malignant or not a simple biopsy is done.

Treatment for malignant tumours is to remove it completely and plastic surgery techniques are used to repair the eyelid defect. It can be completely cured. Sometimes additional treatment may be necessary after the surgery like chemotherapy and radiation therapy.

Iris Tumours

Many iris tumours are only cysts or a nevus, but malignant melanoma can also occur in the iris. Most pigmented iris lesions do not increase in size. Photographs and high frequency ultrasound are used to monitor these lesions. Treatment is only recommended if there is documented growth. Surgical removal of the lesions is the treatment of choice. Radiation plaque therapy and enucleation may be needed for larger iris tumours.

Lymphoma / Leukeamia

The eye, eyelid tissues and the tear ducts can develop tumours of lymphatic origin. Most lymphomas are large cell non-Hodgkin’s lymphoma. The disease is confined to the central nervous system and the eye. Eye symptoms can appear two years before they are seen elsewhere in the body. The treatment consists of external beam radiation, chemotherapy, or both, to the central nervous system. Visual functioning can be affected by the disease as well as the treatment of lymphoma.

Orbital Tumors

The orbit is the bony structure around the eye. Inflammations and tumours of the orbit can occur behind the eye. These tumours can often push the eye forward (proptosis), causing a bulging of the eye, or even downwards (like a lacrimal tumour). Most common conditions causing proptosis are thyroid eye disease and lymphoma. Haemangioma, lacrimal gland tumours and tumours from the sinuses are other causes or orbital tumours. The diagnosis is made by doing special tests which includes; CT-scan, MRI-scan and Ultrasounds, followed by a biopsy of the tumour.

If complete removal is impossible or possesses a threat to nearby structures, a piece of tumour (biopsy) is taken and sent away for histological evaluation. External beam radiation can be used as adjunct to surgical removal or debulking. Extremely large tumours may require removal of the eye and the orbital contents.

Orbital lymphomas are biopsied and treated with radiation therapy or chemotherapy if other parts of the body are involved. All patients undergo proper systemic work-up and management by an oncologist.

Retinoblastoma

Retinoblastoma is the most common primary intraocular (inside the eye) malignancy in children. It presents in the first two years of life with a white pupil, squinting eyes, glaucoma or a red eye. These patients are evaluated using ultrasound, CT-scan and MRI-scans. A systemic and genetic work-up is done with an oncologist.

Treatment of small tumours consists of laser photocoagulation, cryotherapy (Freezing therapy) and chemotherapy. Medium sized tumours can be treated using brachytherapy (radiation), and primary chemotherapy. In the treatment of large tumours chemotherapy is used to shrink the tumour, facilitating local treatment options and avoiding enucleation and external beam radiation. Enucleation (removal of the eye) is indicated if there is optic nerve involvement, or extensive haemorrhage in the eye or the tumour is too large and does not respond to chemotherapy shrinking. This is only done as a life saving measure.

How is eye cancer diagnosed?

By performing a complete dilated eye examination an ophthalmologist can determine if you have an eye cancer. The examination may include a medical history, dilated eye exam, doing an ultrasound, and obtaining photographs. Your ophthalmologist may be able to recognize an eye cancer by its appearance. Biopsy is rarely needed with eye cancers, because opening the eye may risk spreading of tumour cells.

Ultrasound

Sound waves are directed towards the tumour by a small probe placed on the eye. Reflection patterns can confirm the presence of a tumour in the eye. Ultrasound can determine if there is spread of tumour outside the eye, and help determine the thickness of the tumour. Pictures are printed for your ophthalmologist to review.

Photography

Ophthalmologists mainly use two types of photos to assist in diagnosis: fluorescein angiography and fundus photography. Fluorescein angiography uses a dye that is injected into the vein of the arm. Photographs are taken to view the circulation of the retina and the layers beneath the retina. The Fluorescein highlights any abnormality. In fundus photography photos are taken of the retina, macula, fovea, optic disc and retinal vessels.

Additional Evaluations

Depending on what your doctor sees in the eye, he will request special examinations, like CT-scans and MRI-scans. CT-scans are series of X-ray images that provide a clear picture of the eyes, orbit, brain and sinuses. It is a non-invasive quick examination.

MRI-scans use magnetic fields and a computer to create pictures of the inside of the body. Because MRI-scans can “see” through bone it provides clearer pictures of tumours.

What are the latest treatment options?

Your ophthalmologist will recommend treatment tailored for your specific needs. This will be based on your medical history and the findings of the eye examination. Not all eye cancers are treated immediately. When the tumour is small, your doctor may recommend monitoring the growth closely. Treatment will be started if there is any concern. Treatment is usually recommended if there is evidence of growth or if there is a possibility of spreading to other parts of the body.

Chemotherapy

Chemotherapy is the most common type of treatment for cancers in general. It is the treatment of cancer by means of drugs that has a specific toxic effect on cancer cells, and selectively destroys these cancer cells. Many drugs are available and each drug has potential side effects. Although rarely used in eyes, it is sometimes recommended for choroidal metastasis, conjunctival tumours, lymphoma and retinoblastoma.

Cryotherapy

It is the use of very low temperature to treat diseases and tumours. Cryotherapy may be recommended for conjunctival or eyelid tumours. Its goal is to freeze the malignant tumours to stimulate inflammation and scaring.

External Beam Radiation

High energy radiation from X-rays is used to destroy cancer cells and shrink tumours. It is administered by placing a radiation plaque over the tumour (internal radiation or brachytherapy). The external beam radiation may be recommended for choroidal metastasis, choroidal haemangioma, lymphomas, eyelid tumours and orbital tumours.

Radiation Plaque Therapy (Brachytharapy)

It is the most commonly used eye sparing treatment for choroidal melanomas. A radio-active plaque is a small disc shaped device that contains a radio-active source. The plaques are custom made to the size of the tumour. The radio-active plaque is surgically placed over the tumour and the procedure lasts about an hour. Most patients have no problems with the plaque placement surgery. The effects of radiation on the tumour are only seen after three months. Eventually the tumour shrinks, and even though the tumour does not completely disappear, the tumour is considered inactive. Regular monitoring is still needed.

Enucleation

Enucleation is the surgical removal of the eye, leaving the eye muscles, eyelids, lashes, brow and skin. Enucleation is only recommended when there is no other way to remove the cancer completely from the eye. This means that the eye will be permanently blind because an eye cannot be transplanted. When the eye is removed, an implant is placed into the orbit. The muscles are sutured to the implant to allow some movement of the prosthesis. After a healing period a temporary prosthesis is fitted. It is a plastic shell painted to match the other eye, and inserted under the eyelid like a big contact lens. Most patients are very happy with the final prosthetic fitting, and say people cannot tell they have only one eye.