DESCRIPTION: Rare, congenital absence or partial absence of the iris; genetically caused by an autosomal dominant or recessive hereditary pattern. Often, the iris is vestigal (little more than a margin is present) and the eye appears to have no color (only a larger than normal pupil). Other deformities of the anterior chamber are also often present (e.g., cataract), and glaucoma frequently develops before adolescence. There is usually decreased acuity (circa 20/200), photophobia, possible nystagmus, cataracts, displaced lens, and underdeveloped retina; visual fields are usually normal, unless glaucoma develops.
TREATMENT: Pinhole contact lenses; tinted lenses and/or sunglasses; corrections for refractive errors; optical aids; lower illumination levels to control glare. If glaucoma develops (and regular monitoring for this is essential), medical and/or surgical treatment (i.e., goniotomy or trabeculotomy) may help, but long-term prognosis is poor.
IMPLICATIONS: Control glare through lenses or illumination level. Magnification may be helpful.
Genetic counseling is indicated.