Iris Melanoma

Iris malignant melanoma is the most common primary neoplasm of the iris and can be most easily seen by the physician on clinical examination. It is usually a small, discrete lesion, although it may occasionally be diffuse and infiltrative; multiple; and result in heterochromia, glaucoma, chronic uveitis, or spontaneous hyphema. Many patients are often aware of a pigmented spot on the iris that has been present for many years and only recently has begun to grow. With a slit lamp, gonioscopy, and serial slit lamp photography, the ophthalmologist can document the size and growth of the tumor without biopsy. Fluorescein angiography may be helpful in demonstrating the vascularity of the lesion, but is not diagnostic. Ultrasonography is of little value in the evaluation of iris melanoma.

Iris melanoma is relatively benign with a 5-year survival rate of approximately 95%. This is related to the fact that iris melanomas are predominantly of the spindle A-cell type and are usually smaller in size than posterior melanoma because of earlier detection. Conservative management is generally advocated whenever possible, but surgical intervention may be justified with unequivocal tumor growth and with extensive melanomas at initial examination.

Standard treatment options:

1. No treatment with careful observation including serial photography (in asymptomatic patients with stable lesions).

2. With documented growth, excisional surgery:

3. Enucleation (in some patients with diffuse involvement of the iris, with involvement of more than one-half of the iris and anterior chamber angle and documented growth, with extensive iris involvement and intractable glaucoma, with large unresectable tumors and/or extraocular extension, and with tumors in eyes with no salvageable vision).