This is where radiation with charged particles called protons are targeted at the tumour from outside the eye. This treatment is used if the tumour is too large or located too far back in the eye for plaque radiotherapy to work. As this treatment is highly specialised, the Douglas Cyclotron Unit, Clatterbridge, Liverpool is the only centre in the United Kingdom where the treatment is given. If proton beam radiotherapy is the best option for you, we will organise transport to Clatterbridge and accommodation for you in near the Hospital (please see the team photo of the Clatterbridge team and the hospital above). This involves two separate visits to the Clatterbridge. At the first visit a treatment mask is made and fitted- this helps the team target the radiotherapy at the correct part of the eye. At the second visit, one to two weeks later, the treatment is given. You will likely travel down Sunday evening and return Friday later that week. Final measurements are made on the Monday and then the radiation is given over the remaining four days during (Tuesday to Friday). Each treatment session takes around 20 minutes and is pain free. Before going down to Liverpool, however, we have to perform a small operation on the affected eye in Gartnavel General Hosptial, Glasgow. This is where we stitch tantalum markers (small metal discs smaller than a paper clip- please see photo above) to the sclera (white part of the eye) next to the tumour. We usually do this under General Anaesthetic. This helps the team target the radiation treatment more effectively when you go down to Clatterbridge. Proton beam radiotherapy takes a little longer to work than plaque radiotherapy. We usually wait six months to see if the tumour starts to decrease in size. Although effective at treating tumours, the radiation can also damage normal parts of the eye and tissues around the eye when given. This may cause loss of eyelashes, loss of pigmentation of the eyelids, and inflammation of the conjunctiva causing a watery eye. Sometimes small blood vessels can grow at the back of the eye and into the drainage angle at the front of the eye. This can cause the pressure to build up in the eye and cause glaucoma. If we are unable to control the pressure and the eye becomes very uncomfortable, unfortunately we may have to consider removing the eye.