Eye cancer, also known as ophthalmic oncology, is a general term used to describe the various types of tumours related to the eye. They may be found within the eyeball, on its surface or surrounding area around the eye (orbit).
When the healthy cells in or around the eye start to grow uncontrollably, they form a mass which is a tumour that can be benign or cancerous. Eye tumours can be generally categorised into two main categories – ocular adnexal tumours and intraocular tumours.
These are tumours and tumour-like conditions that arise from the eyelids and adjacent regions - tear ducts and eye sockets. Some examples include:
- Eyelid tumours
- Orbital tumours
- Lacrimal drainage system tumours
- Ocular surface tumours
Eyelid Tumours
Eyelid lumps are common and mostly benign, although if neglected, can grow and lead to conditions threatening vision and occasionally life itself. The lumps may be pigmented or non-pigmented.
Benign Eyelid Tumours
Most long-standing stable eyelid lumps are benign and can be observed. However, removal may be considered if they are growing, causing symptoms or suspicious for cancer. If the lumps are small and localised, the procedure can be performed in the clinic for most patients. Some common benign growths include:
- Naevi (commonly known as moles): These may be flat or elevated and vary in colour from normal skin color to dark brown. They may enlarge during puberty and from aging, change in colour with sun exposure but rarely turn malignant.
- Papillomas: Arise from the cells in the superficial layers of the skin, either on their own spontaneously or may be related to the human papillomavirus. They vary in appearance but usually protrude from the skin with little extensions from its surface.
- Pyogenic granulomas: These lumps consist of growing blood vessels and are usually red and fleshy. These can arise after a trauma or an inflammation from a previous eyelid lump such as chalazion, hence resulting in intermittent bleeding.
Malignant Eyelid Tumours
In certain situations, eyelid lumps may be cancerous. This occurs more commonly in people who are older, in less pigmented races (e.g. Caucasians) and those with a history of chronic sun exposure. Some examples include:
- Basal cell carcinoma (BCC): This is the most common malignant eyelid tumour commonly found on the lower eyelid, often varying in appearance and colour. BCC usually starts as a round firm growth with a crater in the middle and rolled up edges on the outside progressively involving adjacent structures.
Basal cell carcinoma - before (left) and after (right) surgical management.
- Squamous cell carcinoma (SCC): Can present as a lump or as a flat scaly plaque with thickened skin over the affected region.
- Sebaceous gland carcinoma (SGC): Asians in particular are more prone to SGC, which is a more serious type of cancer arising from the oil secreting from the Meibomian glands or other glands. This is often misdiagnosed in the early stages where treatment can be therapeutic. In late stages, it may spread to other parts of the face and neck, and not infrequently, elsewhere in the body threatening life.
- Melanoma: These are usually dark-coloured lesions arising from the eyelids, facial skin or conjunctival surface. They may arise from pre-existing pigmented lesions with irregular margins and variable pigmentations. These can increase in size over a short time and spread rapidly regionally or elsewhere in the body.
Orbital Tumours
Benign tumours can form in the orbit (eye socket), arising from the nerves, blood vessels or even the optic nerve. Orbital tumours can affect both adults and children.
Benign Orbital Tumours
The types of benign tumours vary with age group. Common orbital tumours in adults include solitary encapsulated venous malformation (Cavernous haemangioma), Schwannoma, solitary fibrous tumours (SFT) and others. Depending on whether the tumours are vision-threatening, causing discomfort or disfiguring, they may be either observed or require complete removal through an orbitotomy.
Tumours and tumour-like conditions seen in children include dermoid cysts, capillary haemangioma, vascular malformations and rhabdomyosarcoma.
- Dermoid cysts: These are benign growths seen in infancy that are firm and smooth. They continue to grow in size and are typically located at the upper and outer corner. If large or located deep within the orbit, they cause protrusion of the eye, blurred vision and double vision. They are easily managed in early stages with complete removal without recurrence.
- Vascular lesions: may either be tumours (haemangioma) or abnormal vessels (malformations). They usually increase in size and cause bulging eyes, droopy eyelids, abnormal head posture. It may worsen with physical activities or sometimes enlarge, threatening vision. Treatment options include observation, oral medications, injections (steroids, sclerosants, etc) or surgical removal.
Venolymphatic malformation in left orbit - before (left) and after (right) sclerotherapy.
Infantile haemangioma - before (left) and after (right) treatment.
Malignant Orbital Tumours
Cancerous growths in the orbit do occur, mostly in individuals of older age. Growths in the orbit may be also arise from spread (metastasis) of the primary cancer cells in people with a known history of cancers such as breast, prostate, lung cancer and others.
Malignant orbital tumours may either arise from within (common being lymphoma, or less common lacrimal gland tumours), from overlying tissues (conjunctiva and eyelids), and from the nasal cavity and sinuses. They increase in size over time and cause different symptoms depending on the area they affect. They can cause pain, blurred vision, double vision or change in position of the eyeball.
Lacrimal Drainage System Tumours
Tumours of the tear drainage (tear ducts) system are rare, and delayed diagnosis is not uncommon. Tumours of the nasal cavity or the overlying skin can also involve the tear drainage system, where they present as a painless mass located between the eye and nose. Some patients may have blood in their tears without any preceding trauma. In such cases, examination of the lacrimal system and the nasal cavity is necessary. If cancer is confirmed, a wide excision of the tumour with reconstruction is advisable. Chemotherapy and radiotherapy may also be necessary.
These are tumours and tumour-like conditions that arise from the
eyeball and can affect the eye itself. Some examples include:
- Retinoblastoma (primarily seen in children)
- Choroidal melanoma (primarily seen in adults)
- Choroidal metastasis
- Intraocular lymphoma
Retinoblastoma
This is the most common eye cancer children worldwide, affecting 1 in every 12,000 to 15,000 children. It is typically seen around 1-2 years of age. It may present as an abnormal light reflex, a squint (crossed eye) or in late stages as a painful red eye or even bulging eye. If left untreated, most children experience the spread of cancer outside the eye into the eye socket, the brain or to other parts of the body resulting in death. Thus, it not just sight-threatening but life-threatening as well.
Treatment of retinoblastoma has moved away from globe removal to globe preservation. Recent advances in the management of retinoblastoma even for moderately advanced tumours include globe-preserving procedures such as intraarterial chemotherapy (IAC) with chances of complete cure without the removal of the eye ball.
Retinoblastoma – before (left) and after (right) intraarterial chemotherapy with laser treatment.
Advanced retinoblastoma - before (left) and after (right) enucleation with customised prosthesis fitting.
Choroidal Melanoma
Choroidal melanoma is one of the most common solid eye tumours that arise primarily within the eye. These tumours arise in the choroid, which is a blood vessel layer in the eye that lies under the retina.
A melanoma may appear as a dark brown or yellow growth under the retina and is visible to your eye doctor using various instruments. The size of the tumour can be classified according to its thickness; they can be small (0-3mm), medium (3-8mm) and large (>8mm).
This tumour usually occurs in one eye only, and may cause an affected person to have blurring of vision in the affected eye. However, if left untreated, this tumour may spread to different parts of the body that can include the liver, lungs and bones.
Choroidal melanoma
There are 2 basic cell types in melanoma; these are the spindle cell and epithelioid cell types. Sometimes, there may be a combination of the two cell types in a tumour. Patients who have an epithelioid cell type have a higher risk of spread of the tumour and the prognosis may not be as good as compared to patients who have a spindle cell type.
The treatments for choroidal melanoma can include plaque brachytherapy, laser therapy, cryotherapy (freezing therapy), enucleation (removal of the eye).
Choroidal Metastasis
The choroid is the most common site of tumour spread into the eye, in patients who have cancer. These tumours usually appear as a yellow-coloured mass under the retina. Sometimes there may be associated retinal detachment, or fluid collection, around the tumour. There may be a single tumour, or multiple tumours within the eye. Diagnosis is made with a combination of ultrasound, clinical examination and associated tests including studying the blood vessels in and around the tumour (angiography).
Most tumours can be treated with systemic chemotherapy and/or hormonal therapy, radiotherapy. Sometimes local treatment such as laser and cryotherapy treatments can be used.
Choroidal metastasis from breast cancer.
Intraocular Lymphoma
Intraocular lymphoma is a tumour of immature white blood cells, which grows in an uncontrolled fashion. The most common type of lymphoma in the eye is known as vitreoretinal lymphoma. There are 2 types of lymphomas; B-cell and T-cell lymphomas. The diffuse large B-cell subtype is the most common type of lymphoma.
Lymphomas within the eye can be difficult to diagnose, and the ophthalmologist may see white blood cells within the eye, either floating or deposited in various layers in the eye. It can behave like an inflammatory condition in the eye. If the anterior chamber (front compartment of the eye), it can sometimes be seen as floating cells. They may collect behind the retina and appear as small faint yellow patches, sometimes with some brown pigmentation within or around the patches, known as the leopard-skin appearance.
Intraocular lymphoma
Ocular Surface Tumours
Ocular surface squamous neoplasia (OSSN) encompasses a wide spectrum of conjunctival as well as corneal lesions ranging from epithelial dysplasia to invasive squamous cell carcinoma. A wide range of tumours can manifest as epithelial, stromal, caruncular and even a secondary metastatic growth. Although OSSN typically is a localized and slow growing tumour, it can invade the globe and even the eye socket on rare occasions. Most commonly these lesions originate near limbal region of the eye and often localized in the inter-palpebral region, the area most exposed to sun. OSSN could be both non-pigmented as well as pigmented. Medical and surgical treatment, occasionally with brachytherapy may be considered for the treatment of OSSN. Surgical excision has the advantage of serving as both diagnostic and therapeutic role, providing both of accurate histological diagnosis and rapid tumour resolution. Adjuvant therapy in the form of topical chemotherapy reduces the risk of future recurrences.
Ocular surface squamous neoplasia – before (left) and after (right) treatment.
- Person of older age
- Patient with history of cancers
- Certain inherited conditions
- Frequent sun exposure (UV radiation)
- Lighter skin color/ Person of less pigmented race
*People who think they may be at risk should discuss this with their doctor.
The signs of eye cancer can differ depending on the type and site of tumour. Below are some of the common signs and symptoms in eye cancer patients.
Physical changes
- Protrusion of the eye, bulging eyes
- Droopy eyelids
- Abnormal head posture
- Misalignment of the eyes (squint)
Changes in vision
- Blurred vision
- Double vision
- Pain in eye
- Abnormal red reflex (leukocoria)
*A doctor should be consulted should the above symptoms be observed.
In general, most cancers cannot be prevented. Maintaining good health, a healthy diet without undue exposure to alcohol, smoking, sun, etc are generally beneficial. Some retinoblastomas as heritable and may run in families. Such at risk families and their children may undergo genetic testing and be regularly screened with dilated fundus examination from infancy and thus increase the chances of being treated early. Adult choroidal melanomas may arise from pigmented lesions in the eye and thus should also be screened, regularly monitored and treatment instituted early.
Most eye cancers are diagnosed based on the history, clinical presentation and suspicion based on its features. If you are showing possible symptoms or signs of eye tumours, the doctor will need to run some tests in order for a diagnosis to be made. Such tests may include:
- Physical examination: Our ophthalmologists will carry out an examination of your eyes and its surrounding structures, including use of dilating eye drops to increase the size of the pupils in order to thoroughly examine the optic nerve and retina.
- Imaging tests: CT or MRI scans, and ultrasounds may be used to identify the location and size of tumours. In some cases, angiography may be required such as for cases of Choroidal metastasis.
- Incision or excision biopsy: When a tumour is suspected to be cancerous and easily accessible such as the eyelids or eye surface, partial (incisional biopsy) or complete removal (excisional biopsy) may be advised. The tissue is examined by an experienced pathologist under the microscope to confirm whether it is benign or cancerous and confirm complete removal. Surgically inaccessible lesions eg. in the eye, may be managed with chemoreduction, lasers, freezing treatment or other forms of treatment.
There are several treatment options available, depending on the location, type and stage of the cancer. Below are some of the available treatments offered.
Laser photocoagulation
Retinal photocoagulation involves application of high intensity light (LASER) to a tumour to create precise burns to destroy tumour tissue. It is delivered to the patient's retina via a slit lamp, which is a common used examination tool that is used to examine almost all patients who come in to the eye clinic. The laser energy is absorbed into the tumour tissue and the heat produced causes a precise burn to the desired area.
Slit lamp delivered laser photocoagulation
Laser transpupillary thermotherapy
Transpupillary thermotherapy (TTT) is a type of Laser delivery, that causes gradual and prolonged increase in heat production within a tumour, thus destroying tumour tissue. The advantage of this over standard laser photocoagulation is that treatments can be performed more deeply into the tumour.
Photodynamic therapy (PDT)
Photodynamic therapy is a light-based treatment that works alongside a photo-sensitive medicine. With precise calculation, a photosensitive medicine is injected into the patient's bloodstream and collects within the cancer cells. The medicine is activated using light from a laser, specifically in the area chosen by the treating ophthalmologist. The treatment can damage tumour cells directly and also by disrupting the blood supply of the tumour in the affected area, while sparing areas of healthy tissue not within the treatment area. This can help to shrink or destroy the tumour. PDT can sometimes be combined with other forms of treatment.
Chemotherapy
Chemotherapy, better termed as chemoreduction, is generally used to reduce the size of intraocular tumours such as retinoblastoma or extraocular tumours such as malignant eyelid and orbital carcinomas, before other forms of intervention. In the case of retinoblastoma, after chemoreduction, laser or cryotherapy is often performed. In case of orbital and eyelid tumours, surgical excision with reconstruction is performed. Apart from chemotherapy, immunotherapy and targeted therapy may also be employed based on the tumour type, extent and characteristics.
Radiation therapy (EBRT, Plaque brachytherapy)
Radiation therapy or radiotherapy is a treatment that uses beams of intense energy to kill and destroy tumour cells. There are 2 major types – external beam radiotherapy, which uses a machine outside the body to delivery energy to the tumour, and plaque brachytherapy, in which radioactive seeds are placed in close proximity to the tumour (around the eye) to delivery precise energy to the tumour.
Radiotherapy works by using high intensity energy to destroy the genetic material inside a tumour cell, which causes it to die. The goal of radiation therapy is to destroy as much of the tumour cells as possible, while trying to preserve as much normal tissue as possible.
Ophthalmic Brachytherapy
The service maintains close partnership with several other subspecialties which ensures a comprehensive range of services to treat patients using unique multidisciplinary and multimodality approaches. These include paediatrics & adult oncology, radiation oncology, neuro-interventional radiology, rhinology, facial plastic surgery, MOH's micrographic surgery, ophthalmic pathology and the ocular prosthetic teams.
Click here to find out more about our Ophthalmic Oncology Services.