Patients who have had corneal endothelial transplantation have many tests done at each review to monitor recovery and changes in their condition. But what are the specific tests that are done? And what is the purpose of each test? I guess this is a question that every patient has had. The main tests for post-operative review after endothelial transplantation are IOP measurement, anterior segment photography, anterior segment OCT and corneal confocal. The names of these tests do not seem to be unfamiliar, but what they do is probably not very clear to many people. Intraocular pressure is, as the name implies, the pressure inside the eye, which must be kept within a constant range, not high and not low. It is like a balloon, which is supported by gas, and pressure is applied to the walls of the ball, so that the balloon can bulge. If there is less gas, the ball will deflate; if there is too much gas, there is a possibility of bursting at any time. The most important test for patients with corneal endothelial transplantation is IOP measurement. Because some patients have combined glaucoma before surgery, although the glaucoma was controlled before surgery, the glaucoma still exists after surgery, which may lead to fluctuations in IOP; even if some patients originally did not have glaucoma, but used hormones for a long time after surgery, some patients who are particularly sensitive to hormones may also have fluctuations in IOP. If the IOP is high for a long time, not only is there damage to the optic nerve, but also to the endothelial cells of the cornea, which may cause a decrease in the number of endothelial cells. Therefore, monitoring can detect elevated IOP in time and controlling it as soon as possible can avoid irreparable damage. Anterior segment photography is actually a composite of a slit lamp and a camera that is commonly used in outpatient clinics to reflect the results of the slit lamp examination on a photograph. This exam looks at the thickness of the cornea, the state of the cells, and the location of the lesion, and serves as a record of the condition. For example, if a change in the state of the cornea is detected at three months after surgery, it can be compared with the examination at the first month to know if the change is new or old. If the lesion is new, early intervention is required; if the lesion is old, it can be left alone for the time being. OCT is called Optical Coherence Tomography, which is like a CT scan, and is able to see the shape and changes of the internal structures of the eye. For corneal endothelial graft, it can visualize how the corneal graft fits into the stroma, whether there are gaps, the thickness of the graft, etc.