Secondary open-angle glaucoma as an initial presentation of diffuse iris melanoma

We present a case of unilateral, secondary open-angle glaucoma due to an underlying diffuse iris melanoma. The patient was referred by his ophthalmologist with uncontrolled, elevated intraocular pressure in the left eye. He had been treated for asymmetric open-angle glaucoma for over a year prior to referral. Slit-lamp examination and gonioscopy showed prominent asymmetric hyperpigmentation of the left iris, with a nodular pigmented mass in the inferior angle. A biopsy of the lesion showed features consistent with a pigmented iris melanoma. A full systemic work-up was performed, which ruled out any secondary lesions. The patient opted for enucleation over proton beam therapy for treatment. This case highlights the importance of considering secondary glaucoma in patients with unilateral or highly asymmetric glaucoma, and gonioscopy plays an important role in the clinical assessment. Secondary glaucoma due to intraocular melanoma is a rare entity, but has important implications for affected patients.