Intractable secondary glaucoma is seen in –

Iris melanomas may be of two types :- Circumscribed/ Nodular: - It is the most common type which presents as a pigmented spot on the iris. Glaucoma is less common and usually treatable. Diffuse iris melanoma: - Present as a unilateral dark iris (hyperchromic hetrochromia). The tumor has diffusely infiltration pattern of growth and invades the intertrabecular spaces, and plugs the drainage mechanism. This results in intractable secondary glaucoma.