Eye and Optic Nerve Tumours

This record will give you an overview of the tumours affecting the eye and the optic nerve. Follow the links, where given, to more detailed accounts of particular tumours. You may also find the following records relevant:

• Orbital Swellings (covering orbital tumours)
• Conjunctival Problems (covering conjunctival tumours)

Tumours in the eye principally occur in the middle layer (uveal tract: iris, ciliary body and choroid) and inner layer (retina and optic nerve) of the eye. The outer layer (cornea and sclera) is more prone to infections and degenerative disorders - to find out more about those, go to our record on Corneal Problems.

Melanomas¹

These arise in the pigmented uveal tract which is the middle layer of the eye sandwiched between the sclera on the outside and the retina on the inside. All suspected melanomas should be referred urgently to the eye clinic (the patient should be seen within 2 weeks).²

Iris melanoma

• Nature: This accounts for about 5% of uveal melanomas. It is three times commoner in blue/grey irides and extremely rare in black people. It is more commonly found in individuals with certain conditions e.g. dysplastic cutaneous naevi, familial melanoma and neurofibromatosis.¹ They are usually well differentiated and rarely metastasise (rate is about 5%).
• Presentation: Fifth to sixth decade: usually a nodule of ≥3mm in diameter (which may or may not be pigmented) which has a high surface vascularity. There may be pupil distortion ± an associated cataract. The patient may complain of visual decline (pupil distortion, cataract), pain (elevated intraocular pressure) or be asymptomatic.
• Management: Early on, the lesion may simply be observed as some may be apparently inactive. However this is life-long as further growth may prompt surgical treatment or radiotherapy. Diffusely growing tumours may require enucleation (removal of the eyeball).
• Prognosis: These are generally slow growing tumours with an excellent prognosis. However, there is a small group of aggressive variants which grow diffusely and are associated with a poorer prognosis.

Ciliary body melanoma

• Nature: 10% of uveal melanomas arise here.
• Presentation: These tend to develop in the sixth decade of life, usually causing visual symptoms (refractive errors due to the tumour pressing on the lens) but occasionally, this is an incidental finding. Depending on the size and location, there may be dilated episcleral vessels, anterior extension through the sclera, subluxation of the lens or cataract and if there is a posterior extension, retinal detachment.
• Management: Surgery, radiotherapy or enucleation depending on its nature.

Choroidal melanoma

You will find details about Choroidal Melanoma in the dedicated record.

Other iris tumours

Iris naevi

In contrast to melanomas, naevi tend to be flat or only very slightly raised, they are usually <3mm in diameter and are always pigmented. They can cause pupil distortion.

Cysts

Can arise on the iris. Primary ones are rare and the vast majority do not progress and are asymptomatic. Secondary cysts can form as a result of parasitic infection, tumours or long-term use of long-acting miotics.

Other tumours of the choroid

See dedicated record on Tumours of the Choroid for more detail on this topic.

See dedicated records on Retinoblastoma and Retinal Tumours for more detail on these topics.

Optic nerve glioma and optic nerve sheath meningioma

• Background: The principle tumours of the optic nerve include optic nerve glioma and optic nerve sheath meningioma. Gliomas tend to be a disease of early life with 90% presenting by the age of 20 (rarely, they can cause visual loss over several weeks in adults). Meningiomas occur later with a peak incidence between 30 and 60 years of age. 95% of these are unilateral and there is a 4:1 female preponderance.
• Presentation: Gradual, painless fogging or dimming of vision. Rarely, the tumour may bleed into itself causing sudden visual loss. Children may present with strabismus and optic nerve sheath meningiomas occasionally give rise to gaze evoked amaurosis. Examination may reveal poor visual acuity, loss of colour vision, visual field loss, optic disc swelling or optic atrophy. Rarely, if the tumour is large, there may be proptosis ± limitation of eye movements. Signs are usually unilateral unless there is chiasmal involvement.
• Management: Once the diagnosis is ascertained (glioma: CT or MRI; meningioma: STIR (Short TI Inversion Recovery) MRI) the treatment depends on the lesion:
  • Childhood gliomas are generally benign and only treated if there is hypothalamic involvement or progressive visual field loss. Surgical excision is reserved for extreme presentation (blind eye, severe proptosis).
  • Adult gliomas may be highly aggressive, there may be pain and there is a very high mortality rate despite treatment.
  • Meningiomas should be treated with radiotherapy or surgery, depending on individual circumstances.
• Prognosis:Childhood gliomas tend to be benign unlike the aggressive adult type. Life-long review is needed in all optic nerve tumours.

Optic nerve melanocytoma

• Background: This usually benign tumour is made up of melanocytes and melanin. It is static (or grows extremely slowly) and symptoms are due to local pressure effects rather than malignant infiltration.
• Presentation: If the tumour does grow, it may result in a relative afferent pupillary defect, accumulation of subretinal fluid or an enlarged blind spot. If the optic nerve is compressed, visual acuity may be reduced or lost altogether. Compressive vascular problems can also occur e.g. central retinal vein occlusion. If the pattern of growth is such that the artery is compressed, ischaemia and necrosis can ensue which may be accompanied by inflammation.
• Management: There is no treatment available for the tumour per se. As most do not grow, observation will do, the aim being to catch any growth early so that complications of growth (described above) can be managed promptly.
• Prognosis: Generally good as the vast majority of these tumours do not grow.

Other brain tumours can affect the vision due to optic pathway nerve fibre compression. You may wish to find out more about these by going to our records on:

• Meningiomas
• Pituitary tumours
• Craniopharyngiomas
• Space occupying lesions
• Brain tumours in adults
• Brain tumours in children

Background

Primary intraocular-central nervous system lymphoma is an uncommon (although its incidence is increasing),³ non-Hodgkin's lymphoma. It is a diffuse and highly malignant tumour arising within the brain, spinal cord, leptomeninges ± the eye. Risk factors include immunosuppression and Epstein-Barr virus infection.³

Presentation

• CNS features - four different pathological pictures are seen:
  • Solitary/multiple intracranial nodules
  • Diffuse meningeal/periventricular lesions
  • Localised intradural spinal masses
  • Intraocular involvement
• Ocular features - this usually presents with a uveitis-type picture and often precedes CNS involvement by several months or even years. In 80% of cases, both eyes are eventually affected. In addition to the inflammation of uveitis, large infiltrates can be seen underneath the retinal pigment epithelium (they look like a dim spot of light in the fog: hazy yellow patches under the retina that may form a ring - pathognomic).

Management

The vitreous needs to be biopsied (done in theatre) and complemented by a neurological evaluation and MRI. Treatment will be with radiotherapy to the eyes ± whole brain radiotherapy ± intravitreal methotrexate. This will be in addition to systemic treatment (aggressive therapy involving combined intrathecal and intravenous chemotherapy as well as radiotherapy).³

Prognosis

This is a highly malignant tumour with a poor prognosis: the 5-year survival rate is less than 33%.
See our record on Non-Hodgkin's Lymphoma for further details about this condition.