Iris Melanoma Management with Iodine-125 Plaque Radiotherapy in 144 Patients: Impact of Melanoma-Related Glaucoma on Outcomes

PurposeTo evaluate the outcomes of iris melanoma managed with plaque radiotherapy on the basis of the initial presence or absence of glaucoma.DesignRetrospective, comparative case series.ParticipantsA total of 144 patients.InterventionCustom-designed iodine-125 plaque radiotherapy delivering planned 8000 cGy to melanoma apex using transcorneal application.Main Outcome MeasuresTumor control and treatment-related complications.ResultsOf 144 patients with iris melanoma, glaucoma was present at the initial visit in 58 (40%). Causes of elevated intraocular pressure included angle infiltration by melanoma in 50 patients (86%), angle neovascularization in 4 patients (7%), and hyphema in 4 patients (7%). At presentation, the eyes displaying iris melanoma with glaucoma (vs. without glaucoma) were statistically more likely to display angle tumor (66% vs. 43%), with minimal thickness (1.9 vs. 2.9 mm), and melanoma seeding in iris stroma (7 vs. 3 clock hours) and angle (5 vs. 2 clock hours). Plaque radiotherapy was performed in all cases. Kaplan–Meier estimates at 7 years post-treatment revealed no statistical differences in outcomes of local recurrence (14% vs. 15%), enucleation (14% vs. 11%), or metastasis (2% vs. 0%) comparing eyes with and without glaucoma. Of the entire group, multivariate analysis for factors predictive of recurrence included partial (vs. complete) anterior segment irradiation and postradiotherapy glaucoma. Factors related to enucleation included diabetes mellitus, poor initial visual acuity, higher radiation dose to tumor apex, and tumor recurrence. There were no factors predictive of metastasis.ConclusionsIodine-125 plaque radiotherapy provides adequate tumor control for iris melanoma with a low metastatic potential of 1% at 7 years. Iris melanoma with secondary glaucoma showed a statistically significant greater likelihood of flat tumor with iris and angle seeding and no difference in outcomes compared with eyes without glaucoma.Financial Disclosure(s)The author(s) have no proprietary or commercial interest in any materials discussed in this article.