Eye Cancer: Comprehensive Cancer Information

Eye Cancer: A Comprehensive Guide

General Information

More than two dozen types of cancer can develop in the various structures in and around the eye. These include subtypes of melanoma, lymphoma, sarcoma, and carcinoma.

Structures of the Eye

The eye and its surrounding area are composed of several key structures where cancer may develop:

Eyeball

Internal structures like the uvea, retina, and vitreous.

Uvea

The middle layer of the eyeball, comprising:

  • Iris: The coloured part of the eye.
  • Choroid: A thin layer providing the eye with essential nutrients.
  • Ciliary body: Contains muscles for focusing and cells that form aqueous humour (the clear liquid at the front of the eye).

Vitreous

The gel-like fluid that fills the main part of the eyeball.

Retina

The light-sensitive cell layer at the back of the eye, connected to the brain by the optic nerve.

Orbit

The bony space around and behind the eye, containing important nerves (including the optic nerve), the lacrimal gland, and eye-moving muscles.

Lacrimal gland

Located in the upper outer quadrant of the orbit, this gland produces tears.

Eyelid

Tumours can affect the skin or the inner layer (tarsus and conjunctiva).

Conjunctiva

The surface covering of the eye that also covers the inside of the eyelid.

Lacrimal sac/duct

The structure responsible for draining tears, located near the nose in the inner lower quadrant of the orbit.

Types of Eye Cancer

Eye cancers are categorised by their primary location:

Cancers Inside the Eyeball

  • Uveal melanoma (Choroidal melanoma): The most common primary intraocular eye cancer in adults, originating in the uvea (iris, ciliary body, and choroid).
  • Retinoblastoma: The most common malignant tumour that starts in the eye among children, typically occurring before age five.
  • Metastatic intraocular tumours: Cancers (most commonly breast, lung, and gastrointestinal cancers) that spread from other parts of the body to the eyeball.

Note: Non-cancerous growths like Circumscribed choroidal hemangioma and Retinal hemangioblastoma may also occur in the eye structures.

Cancers of the Eyelid

  • Basal cell carcinoma: Accounts for over 90% of eyelid cancers and is usually not aggressive.
  • Squamous cell carcinoma: A less common but more aggressive form of skin cancer on the eyelid.
  • Cutaneous melanoma: A potentially life-threatening form of skin cancer affecting the eyelid skin or conjunctiva.
  • Sebaceous carcinoma (Meibomian gland carcinoma): A rare type that affects the oil-producing glands of the eyelids and can be mistaken for non-cancerous conditions like a sty.
  • Merkel cell carcinoma: A rare but fast-growing, aggressive cancer.
  • Metastatic eyelid tumours: Cancers that have spread to the eyelid.

Cancers of the Conjunctiva

  • Squamous cell carcinoma: The most common type of conjunctival eye cancer, affecting the cornea area or inner eyelid layer.
  • Conjunctival Melanoma: Can occur on the surface of the eyeball or the inside of the eyelid.
  • Metastatic conjunctival tumours: Cancers that have spread to the conjunctiva.

Cancers of the Orbit, Lacrimal Gland, and Lacrimal Drainage System

  • Orbital sarcoma: Sarcomas arising from muscle or fatty tissue, with rhabdomyosarcoma being the most common type in children.
  • Adenoid cystic carcinoma: A rare, potentially life-threatening cancer of the lacrimal gland.
  • Squamous cell carcinoma (Lacrimal sac/duct): The main cancer type in the lacrimal sac and nasolacrimal duct.
  • Transitional cell carcinoma: A cancer of the lacrimal sac.

Note: Non-cancerous tumours like Orbital and optic nerve meningiomas and Pleomorphic adenoma (of the lacrimal gland) also occur.

Lymphomas of the Eye

Cancer of the white blood cells that can affect the vitreous, choroid, conjunctiva, or adnexa (surrounding structures). Types include Diffuse large B-cell lymphoma and indolent lymphomas like Marginal zone lymphoma and Follicular lymphoma.

Risk Factors

Factors that may increase the risk of developing eye cancer include:

  • Having light skin and/or blue eyes.
  • Exposure to the sun or tanning salons, which may increase the risk of carcinomas or melanomas on the eyelid.
  • Nevus of Ota: A large birthmark associated with a high number of melanocytes.
  • Exposure to certain viruses such as Human Papilloma Virus (HPV), which may increase the risk of squamous cell carcinoma of the conjunctiva.
  • Atypical mole and melanoma syndrome (AMS): Characterised by a large number of atypical moles.
  • Certain genetic conditions, including Von Hippel Lindau disease and mutations to the RB1 and BAP-1 genes.

Symptoms

In the early stages, eye cancer often has no symptoms. When signs do appear, they can vary and may include:

Vision Changes

Loss of vision, blurry or double vision, flashing lights, or floaters (objects in the field of vision).

Physical Changes

  • Leukocoria (a white reflection in the pupil).
  • A pigmented (dark) area on the conjunctiva.
  • A growing dark spot on the iris.
  • A change in the pupil's shape or size.
  • A change in the eyeball's position or movement, or a bulging eye.

Eyelid Changes

  • A small, firm, raised lump with a central lesion on the eyelid.
  • Ulceration of the eyelid.
  • Loss of eyelashes.
  • A brown or pigmented lesion on the eyelid.
  • A sty that does not heal with medical treatment.

Other

Orbital or ocular pain, excessive or bloody tears.

Important: These symptoms may signal other health problems and should always be discussed with a doctor.

Diagnosis

Patients with suspected eye cancer should consult an ophthalmologist (a medical doctor specialising in the eye) who has specific training in diagnosing eye cancers. Diagnosis involves several tests and exams:

Eye Exams

A dilated retinal exam and ultrasound imaging for tumours of the eyeball, and a careful inspection of the outside of the eye and eye movements for orbital, eyelid, and conjunctival tumours.

Imaging Exams

Used to identify the location, size, and shape of the suspected tissue. These include:

  • CT or CAT (computed axial tomography) scans.
  • PET (positron emission tomography) scans.
  • MRI (magnetic resonance imaging) scans.
  • Optical coherence tomography (OCT).
  • Ultrasound (sonogram).

Biopsy

The removal of a small tissue sample for microscopic examination. Biopsies are used in limited circumstances to diagnose eye cancer and may require local or general anaesthesia depending on the tumour's location.

Molecular and Genetic Testing

Used to look for specific mutations in tumour cells to assess the risk of metastasis or to plan treatment. Genetic testing can also determine if the patient has an inherited form of eye cancer.

Blood Tests

Performed to monitor the body's response to ongoing treatment.

Treatment

The treatment of ocular cancers is highly specialised. At SSCHRC, care is personalised to include the most advanced therapies while minimising the impact on the body. Our primary goals are successful treatment, preserving the eye and vision whenever possible, and restoring the patient's appearance after treatment.

Treatment options are determined based on several factors, including: the type of cancer, its location and size, whether it has spread (metastasised), and the patient's age and overall health.

One or more of the following therapies may be recommended:

Surgery

  • Eye-preserving surgery: Used in select cases to remove cancer while aiming to preserve the function and aesthetic appearance of the eye.
  • Iridectomy: Surgical removal of the iris (the coloured part of the eye).
  • Enucleation: Removal of the entire eyeball, typically for advanced uveal melanoma.
  • Orbital exenteration: A rare surgery involving the removal of the eye, eyelids, and surrounding tissues, reserved for very advanced disease.
  • Eye reconstructive surgery: Following enucleation or exenteration, a specialised team fits the patient with a custom-made prosthetic eye.

Radiation Therapy

Uses focused beams of energy to kill cancer cells, precisely targeting the tumour to minimise damage to healthy tissue. Types offered include:

  • Intensity Modulated Radiation Therapy (IMRT)
  • Volumetric Modulated Arc Therapy
  • Brachytherapy
  • Stereotactic Radiosurgery (SRS)

Chemotherapy

Drugs used to kill cancer cells or control their growth. It can be delivered in several ways:

  • Intravenous: Injected into a blood vessel for systemic distribution.
  • Intra-arterial: Delivered directly to the eye via a catheter from the groin, avoiding systemic exposure (a preferred technique for retinoblastoma).
  • Intravitreal: Injected directly into the eye.
  • Periocular: Placed around the eye.

Topical chemotherapy in the form of eye drops is also used for some cancers (e.g., sebaceous carcinoma, conjunctival squamous cell carcinoma).

Targeted Therapy

Drugs designed to interfere with the specific molecules that cancer cells need to survive, multiply, and spread. This is used for eye cancer that has spread to other parts of the body.

Immunotherapy

Therapy to improve the immune system's ability to fight cancer, also used for eye cancer that has spread. Types include:

  • Immune Checkpoint Inhibitors
  • Monoclonal Antibodies

Laser Therapy

Uses an intense, focused beam of light to destroy cancer tissue, sometimes used for uveal melanoma and metastatic tumours inside the eyeball.

Cryoablation (Cryotherapy or Cryosurgery)

Uses extreme cold (freezing) to destroy cancerous tissue. It is sometimes performed as an outpatient procedure.

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