Adjunctive Treatment of
Ocular Surface Dysplasia
Intra-Epithelial Neoplasia – Mitomycin C
Mitomycin C is a chemotherapy agent that is used to treat other forms of internal cancer elsewhere in the body. In yourself, it is only being used on the surface of the eye either to try and prevent the high risk of recurrence following surgical excision of localised non-invasive dysplastic lesions or as the sole treatment of more extensive lesions. Mitomycin C is used in a drop form and kills the lesion by preventing division of the rapidly dividing tumour cells.
The usual treatment regimen is one drop four times per day for one week. This is then repeated two more times with a week off between each of the three courses. You will be reviewed at the end of every week of the three courses.
Side effects are common and include redness, watering and irritation of the eye during the week of treatment, but these usually settle rapidly once the drops are stopped at the end of the week. Allergy to Mitomycin C is also common (one third of patients), and the eye and eyelids may become very red, swollen and itchy. Please notify the rooms during the day if this should occur. Significant pain is unusual and should be reported immediately.
If you have a reaction to the Mitomycin C drops then other forms of chemotherapy drops may be substituted, for example 5FU or Interferon.
There have been no reported side effects in other parts of the body following treatment of Mitomycin C on the eye.
If the drops are taken correctly, then the risk of the lesion recurring is close to zero. You will need to be reviewed 3 months following completion of the Mitomycin C treatment and then six monthly for a few years to monitor for the very small risk of recurrence of this lesion.
Rarely, recurrence of this lesion can give rise to cancer on the surface of the eye. It is vital that follow-up appointments are made before leaving after each visit. If you cannot make an appointment or miss a scheduled appointment, then it is important that you ring the rooms to make a new appointment.
Invasive Neoplasia (Squamous Cell Carcinoma) – Beta Radiotherapy
Beta Radiotherapy acts by stopping multiplication of rapidly dividing cancer cells that may have been left behind following surgical excision of the lesion. Beta Radiotherapy is more penetrating than Mitomycin C and is able to destroy invasive cancer cells that cannot be reached by these chemotherapy drops alone. The aim of the treatment is to reduce the risk of the remaining lesion invading the eye or the tissues surrounding the eye, without significant damage to the eye itself.
Treatment involves application of radiotherapy by means of a flat plate held on the surface of the eye for up to one minute. It is performed after application of local anaesthetic drops and the whole process takes less than fifteen minutes. There is very little in the way of discomfort either during or after the treatment. The procedure is then repeated on consecutive days for a total of three or four days.
Long term side effects of the radiotherapy are rare and usually involve localised redness of the surface of the eye over the area that was treated. The radiotherapy penetrates very poorly into the eye so that the risk of cataract or damage to the retina or structures surrounding the eye is extremely small.
Unfortunately the radiotherapy cannot guarantee a complete cure of the cancer and you will need to be kept under observation indefinitely. You will need to be seen 3 months following completion of the radiotherapy, then six monthly for two years, then on a yearly basis, to monitor for the small risk of continued growth of this lesion.
The risk of this cancer spreading to other parts of the body is very small indeed, but it is vital that follow-up appointments are made before leaving after each visit. If you cannot make an appointment or miss a scheduled appointment, then it is important that you ring the rooms to make a new appointment.