The most common eye conserving way of treating posterior uveal melanoma is by radiotherapy. This is usually delivered by means of episcleral radioactive plaques. Cobalt-60, ruthenium-106, and iodine-125 are the radioactive materials most commonly used. Other methods of radiotherapy of posterior uveal melanoma include teletherapy using charged particles of proton and helium ion beams; recently, stereotactic radiosurgery using the Leksell gamma knife has been described as being efficient. After radiotherapy, most uveal melanomas show significant reduction in size, although complete disapperance is not common. Histological evaluation of residual tumours have demonstrated that most of the tumours harbour viable melanoma cells, and some of these cells show proliferating activity using immunohistochemical markers.