Tumours of the eye
Tumours inside and on the surface of the eye can be benign or malignant, and can also be primary or secondary. Certain lesions in the eye such as naevi or moles are very common, and usually do not require treatment. Other lesions such as melanoma are rare, and require specialised treatment, such as surgery or radiotherapy.
Naevus and Melanoma
Naevus is a benign mole on the eye. Some occur on the surface of the eye, in the conjunctiva, and others are found inside the eye, in the iris, ciliary body or choroid. Inside the eye, an optometrist or ophthalmologist often finds these on examination. Most moles are monitored, though some may require treatment if they are causing vision problems. If moles show sign of change, either by growth or an increase in suspicious features then treatment might be necessary if they have changed into malignant melanoma. This is usually a diagnosis in adults. Many malignant melanomas inside the eye can be treated by radiotherapy. Radiotherapy can be delivered by plaque brachytherapy or proton beam radiation. Plaque radiotherapy is a localised form of radiotherapy, where a radioactive metal device (the ‘plaque’) the size of a 10 pence coin is sutured to the external surface of the eye for a certain number of days, under a general anaesthetic or occasionally under local anaesthetic with sedation. Proton beam radiotherapy requires markers to be surgically placed on the eye and then radiation is delivered to the eye separately. Larger melanomas require radical surgery, such as removal of the eye. In this procedure, the eye is removed, and an implant is inserted in the socket, with a painted artificial eye worn over this, giving a good cosmetic result.
Tumours on the surface of the eye usually require excision, which may be supplemented with freezing treatment (cryotherapy) to prevent recurrence. Further treatments such as chemotherapy drops may be required.
Vascular tumours of the eye
Haemangiomas and vasoproliferative tumours are benign vascular tumours. Most are asymptomatic. Some types of vascular tumour can be part of generalised disorders, such as von HippelLindau syndrome or Sturge Weber syndrome, but other haemangiomas are not part of a syndrome. Treatment is dependent on the type of lesion, its features such as disturbance of surrounding tissues and potential for causing problems with the sight or eye in the future. A range of treatments can be employed from laser, to photodynamic therapy to radiotherapy.
This is a childhood cancer of the primitive retina and is rare, occurring in approximately 1 in 18,000 live births. It presents with a white-eye pupil reflex or a squint, though there are many other more common causes of these clinical signs. Retinoblastoma can occur in one or both eyes depending on the timing of the genetic mutation that causes tumour formation. Treatment is complex, ranging from chemotherapy to localised treatments such as laser, cryotherapy, localised chemotherapy, radiation, or eye removal. Chemotherapy can also be given into the ophthalmic artery (intra-arterial chemotherapy) or under special conditions into the eye itself (intravitreal chemotherapy).
Other tumours of the eye are very rare. Examples include osteomas, which can cause visual problems. Lymphoma of the eye (primary intraocular or vitreoretinal lymphoma) can affect the vitreous and retina, and usually requires extensive treatment with input from an oncologist. Local treatments with intravitreal methotrexate injections are sometimes necessary to control ocular disease. Choroidal lymphomas may be primary and are often low grade, usually amenable to radiotherapy.
Cancers from other sites in the body can seed into the eye. In many cases the site of the primary cancer is already known, but in about one third, the first presentation of the cancer is in the eye. Extensive investigation is required when such a deposit is found. Treatment is directed towards the underlying cancer, as well as the eye, using radiotherapy and in some cases local treatments to the eye to preserve vision.
Conditions such as radiation retinopathy, diabetic retinopathy, retinal vein occlusionsand Coats’ disease are blood vessel abnormalities. A range of treatments is employed to control the visual effects of these, including laser and antiVEGF injections, usually given under local anesthetic. Age-related macular degeneration is of two forms: the dry form (which causes a slow decline in vision) and the wet form (which usually presents with a rapid decline in vision). The wet form is usually treated with antiVEGF injections. Other medical retina conditions may need only observation.