The left eye continued to do well, with a visual acuity of 20/20 and an intraocular pressure of less than 20 mmHg, until April 1996. At that time, the patient sought treatment for a 3-day history of eye pain; intraocular pressure was 32 mmHg OS. Slitlamp examination showed patchy pigmentation over the entire iris surface and within the bleb cavity (Figure 1B). High-frequency UBM of the bleb and adjacent structures was performed with an Ultrasound Biomicroscope Model 840 (Zeiss Humphrey Systems, Dublin, Calif). This instrument hasa frequency of 50 MHz and a lateral and axial resolution of 50 µm. The penetration depth is 5 mm. It scans at a rate of 8 Hz with a sampling resolution of 5 µm. Ultrasound biomicroscopy showed evidence of tumor proliferation within the sclerectomy and filtration bleb (Figure 2). The eye was enucleated. Results of a metastatic workup, including a chest radiograph, liver function tests, and a computed axial tomographic scan of the abdomen and pelvis, were normal. Seven years later, the patient was in good health and without evidence of metastatic disease.