Benign tumors of the iris

Up to 84% of iris tumors are benign, more than half of them (54-62%) are myogenic in nature.

[1], [2], [3], [4], [5]

Leiomyoma of the iris

Leiomyoma of the iris develops from the pupillary muscle elements, is characterized by extremely slow growth, it can be pigmentless and pigmentless. The variety of color of the tumor can be explained by the morphogenesis of the iris. The fact is that the pupillary muscles of the iris are formed from the outer layer of the pigment epithelium of the iridociliary primordium. In embryogenesis, iris sphincter cells produce melanin and myofibrils; in the postnatal period, the ability to produce melanin disappears, but the dilator retains it. This can explain the appearance of non-pigmented leiomyomas, developing from the sphincter, and pigmented leiomyomas, formed from the dilator elements. The tumor is diagnosed mainly in the third - fourth decades of life.

The non-pigmented iris leiomyoma grows locally in the form of a yellowish-pink translucent proinminous node. The tumor is localized along the edge of the pupil or, more rarely, in the basal zone (in the region of the ciliary crypts). The boundaries of the tumor are clear, the consistency is loose, gelatinous. On its surface, translucent outgrowths are visible, in the center of which there are vascular loops. Leiomyoma, located at the edge of the pupil, leads to a reversal of the pigment rim and a change in its shape. When the tumor is localized in the area of the ciliary crypts, one of the first symptoms is an increase in intraocular pressure, so such patients are often diagnosed with a unilateral primary glaucoma.

The pigment leiomyoma of the iris has a color from light to dark brown. The form of the tumor can be nodal, planar or mixed. It is more often localized in the ciliary belt of the iris. Characteristic changes in the shape of the pupil, its elongation due to the reversal of the pigment border, directed toward the tumor. The consistency of pigment leiomyoma is more dense than pigmentless, the surface is tuberous, the newly formed vessels are not visible. Germination of the tumor in the angle of the anterior chamber more than 1/3 of its circumference leads to the development of secondary intraocular hypertension. Symptoms of tumor progression are considered to be changes around the tumor: a smoothness of the iris relief and the appearance of a pigment spraying zone, pigmentary tracks directed to the sides of the tumor, a vascular corolla in the iris; the shape of the pupil also changes. Sprouting into the structures of the anterior chamber angle and the ciliary body, the tumor emerges into the posterior chamber, causing displacement and clouding of the lens. The diagnosis can be established on the basis of the results of biomicro-, gonio-, diaphanoscopy and iridoengiography. Surgical treatment: the tumor is removed along with the surrounding healthy tissues (blockexcision). When removing not more than 1/3 of the iris circumference, its integrity can be restored by superimposing micro-stems. As a result of restoration of the integrity of the iris as a diaphragm, the degree of severity and frequency of lens astigmatism are significantly reduced, and light aberrations decrease. The prognosis for life is favorable, for vision depends on the initial tumor size: the smaller the tumor, the greater the probability of maintaining normal vision.

Nevus Iris

The color of the iris and the pattern of crypts in each person are genetically programmed. Its coloration is practically non-uniform in all: on the surface of the iris, areas of hyperpigmentation in the form of small specks - "freckles" can be scattered. True nevi refers to melanocytic tumors, the derivatives of the neural crest. They are detected in both children and adults. Clinically, the nevus of the iris has the appearance of a more intensely pigmented portion of the iris. Its color varies from yellow to intense brown. The surface of the tumor is velvety, slightly uneven. Sometimes the nevus slightly protrudes above the surface of the iris. Its boundaries are clear, the iris pattern on the surface of the nevus is smoothed, in the central part, where the tumor is denser, the pattern is absent. The dimensions of the nevus range from a pigmentation area 2-3 mm in size to large foci occupying one quadrant of the iris surface and more. With progression, the tumor darkens and grows, sputtering of the previously not observed pigment and the corolla of dilated vessels around it, the boundaries of education become less distinct. Stationary nevi should be monitored. When the nevus progresses, its excision is shown. The prognosis for life and vision is good.