There are many different benign and malignant tumours that can affect the cornea, conjunctiva and eyelids.
Some of these are obvious as discrete abnormal growths on the surface of the eye but some are only detectable with careful examination. They may cause irritation, redness or disturbance of vision in any combination.
The most common of the ocular surface tumours is Ocular Surface Squamous Neoplasia (OSSN), this also has been known by many other names such as conjunctival intra-epithelial neoplasia, epithelial dysplasia or Bowen’s disease).
OSSN is initially a precancerous lesion within the conjunctival, limbal or corneal epithelium but can become invasive squamous cell carcinoma if not treated. It can be a localised tumour on the surface of the eye or very diffuse and hard to distinguish from other causes of conjunctivitis. It can sometimes affect vision without being very obvious otherwise.
Treatment for OSSN starts with clinical diagnosis then confirmation with either impression cytology or a biopsy.
Smaller and more discrete lesions can be removed surgically with an excision biopsy (removing the whole lesion) combined with adjunctive treatments such as intra-operative application of mitomycin C or cryotherapy to help prevent recurrence.
More extensive lesions are not amenable to surgical excisions it would cause irreparable damage to the surface of the eye. These are treated with topical chemotherapy in the form of interferon or mitomycin C eyedrops or retinoic acid ointment. These medications are not available at any pharmacy and need to be specially made up by a compounding pharmacy. The treatment may need to be continued for 6-12 months in some cases. Long term follow-up is always required as there may be recurrence many years later.
Conjunctival naevi are variably pigmented patches on the surface of the eye that may become more obvious during teenage years. Most of the time the diagnosis of these is clinical but sometimes a biopsy is required.
Primary acquired conjunctival melanosis (PAM) is a pigmented lesion that may be multifocal or affect both eyes that develops later in life and can sometimes change into conjunctival melanoma. These lesions may need to be biopsied and treatment with topical chemotherapy or cryotherapy may be used if there is concern about progression. Smaller affected areas can be removed surgically.
Conjunctival melanoma is rare but has the same concerns as melanoma elsewhere in the body. Treatment is aimed at diagnosis and local control of the lesion with excision and topical chemotherapy and cryotherapy where appropriate as well as assessment for metastatic spread.