Timothy W. Olsen, M.D., an ophthalmologist and vitreoretinal surgeon at Mayo Clinic in Rochester, Minnesota, demarcates a large choroidal melanoma using ceramic fiducial marker. This patient will follow up in two days with Gamma Knife radiation and stereotaxic surgery to kill the tumor. Hi, my name is Tim Olson. I'm a vitro retinal surgeon at the mayo clinic in Rochester. And today we have a challenging case. This is a young person, a 24 year old who's been diagnosed with a large Kuroyedov melanoma. Our goals for today are to demarcate this tumor. We use ceramic fiduciary markers to demarcate the tumor on the external wall of the eye. We also want to biopsy the tumor to see what the pathology is and what the genetic risk factors are. So we'll do an external transcultural biopsy. The muscle you see here is the lateral rectus muscle of the left eye and the is located as a mound in the center. The area with the sentinel vessel. Right here is the area where the is involved. So at first we'll just trans illuminate and see how much we need to open. So what we're doing is just decisional opening of the contract for 360°, opening Tainan's capsule around each of the four rectus muscles so that we can get a suture around rectus muscles. We're coming perpendicular with the loaded and bring it up. And she really did it with the heel of the hook. So we've got the lateral rectus. And in theory rectus secured this dark shadow is the edge of the tumor. So we're just gonna draw a line around that with a marking pen. Okay, so we have the lower border of the tumor marked at this point and we're gonna find the upper border. So what we'll do is we'll mark these and then under the microscope. We'll put the fiduciaries on there. Okay? So these are markers that we use for radio surgery. They our carbon fiduciary, they show up really well on M. R. I. Scan. So when they do the M. R. I. Scan tomorrow, they'll be able to nicely localize this. So this will define kind of the infra temporal corner of the tumor. Yeah. Now that you can see this is right at the border of the medial border of the superior rectus insertion. Okay, so what we're gonna do is make a little trap door here. So you want this about This flat at about 60-70% depth? Alright, so we'll make a small incision here through. We're in the tumor there. Okay? We have a specimen and we're just closing the flat door over the you say. So right now we've got three stitches in there, one in each Corner and one in the middle. Okay?