Glaucoma After Iodine-125 Brachytherapy for Uveal Melanoma: Incidence and Risk Factors.

Abstract

To report the incidence and identify risk factors for secondary open-angle glaucoma and neovascular glaucoma after iodine-125 brachytherapy for uveal melanoma in a tertiary ocular oncology and glaucoma practice. Eyes of patients who had been diagnosed and treated with iodine-12 brachytherapy for uveal melanoma over a 10-year period were included for review. Secondary open-angle glaucoma was defined as meeting the following criteria: at least 3 measurements of intraocular pressure (IOP) ≥21 mm Hg after the removal of the iodine-125 plaque and an open angle on gonioscopy. Neovascular glaucoma was defined as meeting the following criteria: at least 3 measurements of IOP ≥21 mm Hg and neovascularization of the iris or anterior chamber angle. Cumulative incidence was calculated and survival analysis was used to analyze risk factors for both secondary open-angle glaucoma and neovascular glaucoma. A total of 374 eyes in patients diagnosed with uveal melanoma and treated with Iodine-125 brachytherapy were included in the study. Thirty-one eyes (8.6%) were diagnosed with secondary open-angle glaucoma and 25 eyes (6.7%) were diagnosed with neovascular glaucoma. Multivariate analysis identified the following risk factors for secondary open-angle glaucoma: older age, greater tumor size, iris location of uveal melanoma, higher baseline IOP, ciliary body involvement, and eyes having undergone combined brachytherapy with vitrectomy and silicone oil placement for radiation attenuation. The risk factors for neovascular glaucoma were as follows: greater tumor size, greater number of pack-years smoking history, pseudophakia, and higher grade of radiation retinopathy severity by fluorescein angiogram. We have identified additional risk factors for the development of both secondary open-angle glaucoma and neovascular glaucoma in patients with uveal melanoma who have undergone iodine-125 brachytherapy for local tumor control. The risk of secondary glaucoma is substantial. Close ophthalmic monitoring of patients is necessary for detection and timely treatment of glaucoma to maximize visual outcome.