Amy, a 22-year-old student, saw her optician for a routine eye examination. He noted the presence of a small lesion on the inside of her left lower lid. Amy did not recall this from previous eye tests. She was fair skinned with multiple moles but no past or family history of skin cancer.
She was mildly myopic and also occasionally wore contact lenses. She had not experienced any discomfort, discharge or bleeding from the eye. Following her optician's recommendation, she decided to see her GP and the lesion was photographed and kept under regular review.
She was also advised to keep an eye on her other moles and report any changes to her doctor. Several months later the pigmented lesion appeared to increase in size and Amy consulted her GP again.
She was referred for an urgent opthalmological opinion, which concluded the lesion was benign naevus. However given the change it was excised as a day case procedure.
The procedure was uneventful and routine histology confirmed the benign nature of the lesion and Amy was reassured.
Ocular melanoma is a rare eye tumour in adults with around 500 new cases diagnosed every year. Uveal melanoma is the most common type and occurs around the choroid, ciliary body and iris. Another type known as conjunctival melanoma can also occur more rarely on the conjunctiva or eyelid.
Excessive exposure to sunlight is an important contributory factor, particularly in fair, blue-eyed individuals. The incidence is also slightly higher in men and peaks around 55 years of age.
A strong family history is a risk factor and there is an association with dysplastic naevus syndrome (>100 moles on the body). Tumours can also metastasise to the eye from other parts of the body.
Melanomas can be asymptomatic or present with change in eye colour, pain, red or bulging eyes or visual loss. When assessing eyes an 'ABCDE approach' to skin lesions should still be used. Any changes in size or pigmentation are significant pointers to whether it should be referred for excision and histological confirmation. Ophthalmoscopy, ultrasound, skin biopsy or CT/MRI scans can be used to reach a diagnosis.
Treatment is aimed at curing the cancer and preserving vision although the latter may not always be possible. Radiotherapy, thermotherapy or surgery can all be used as treatment options.
Local tumour control can be achieved in around 90 per cent of patients. However tumours are often not found early and metastases can be present in 40 per cent of patients at five years. Apart from metastases - most commonly to the liver, lungs or bone - other complications include visual loss or retinal detachment.
Treatment for large eye melanomas is more likely to lead to visual loss through enucleation (removal of the eyeball) than small ones.
In conclusion, ocular melanoma remains a rare but important cancer in patients. Patients will need regular follow up with X-rays or scans for many years even after successful treatment.
- Dr Aziz is a GP in Bristol