RESUMO
INTRODUCTION: Ring melanoma is a rare form of uveal melanoma characterized by the circumferential involvement of the ciliary body. Unilateral chronic and refractory glaucoma is a classic circumstance of diagnosis. OBSERVATION: We report a case of ring melanoma revealed by acute intraocular hypertonia secondary to spontaneous hyphema. Iris and iridocorneal angle were diffusely invaded by the tumor. The fundus was masked but B-scan ultrasonography revealed a voluminous ciliochoroidal tumor. The patient had been enucleated. Pathological examination confirmed the diagnosis of ring melanoma. The tumor involved angle structures. The patient died 1 year later because of metastasis. DISCUSSION: Acute or chronic ocular hypertonia is a classic but rare circumstance of uveal melanoma diagnosis. Many mechanisms exist: neovascular glaucoma, secondary angle closure, involvement of angle structures, and trabecular obstruction by tumor cells or pigment. Acute intraocular hypertonia secondary to hyphema is more exceptional. Our observation highlights that apart from the classic situation of acute angle closure glaucoma, intraocular hypertonia requires meticulous fundus examination, if necessary using B-scan ultrasonography.