A case of metastatic iris tumor observed with anterior segment optical coherence tomography before and after radiation therapy

Background/Aim: Metastatic iris tumors are relatively rare entities that are often treated with radiation therapy; however, it remains difficult to evaluate the effectiveness of treatment. Anterior segment optical coherence tomography (AS-OCT) provides high-resolution crosssectional images with no dye injection, and may thus be useful for evaluating iris tumors. Herein, we report a case of metastatic iris tumor examined with AS-OCT before and after radiation therapy. Case Report: A 56-year-old Japanese woman complained of ocular hyperemia and pain in her right eye, and was referred to our hospital because of uveitis and an iris mass. One year before the initial visit, the patient was diagnosed with lung adenocarcinoma, and treated with chemotherapy. She also underwent radiation therapy 4 months ago due to multiple bone metastases. Slit-lamp microscopy revealed a 2×2 mm elevated lesion with partial depigmentation on the lower iris. AS-OCT examination revealed that the mass was located in the iris stroma with an irregular anterior surface. Based on fine needle aspiration cytology, she was diagnosed with metastatic iris tumor derived from lung adenocarcinoma, leading to local radiotherapy. Seven months later, AS-OCT showed shrinkage and atrophy of the iris tumor with peripheral anterior synechia formation. Conclusion: We report a case of cytology-proven metastatic iris tumor observed with AS-OCT before and after radiation therapy. This study highlights the potential usefulness of ASOCT for monitoring changes in tumor size and configuration following radiotherapy.