Aniridia: causes, symptoms, diagnosis, treatment

Congenital aniridia is the absence of iris. With a thorough examination, sometimes find small fragments of the root, iris. This pathology can be combined with other malformations - microphthalmia, subluxation of the lens, nystagmus. Congenital aniridia is accompanied by amblyopia, hypermetropia, and sometimes secondary glaucoma. Aniridia can also be acquired: as a result of a strong blow, the iris can completely come off at the root.

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Heredity

1. Autosomal dominant. The most common form of inheritance. The disease is two-sided and has various expressiveness.
2. Autosomal recessive. It occurs less frequently; enters the symptom complex of Gillespie syndrome (Gillespie).
3. Sporadic origin occurs in approximately one-third of all cases of aniridia. In some situations, a deletion of 13p is found. Aniridia can accompany Wilms' tumors, combine with mental retardation, the pathology of the genitourinary system and malformations. Patients with this form of aniridia undergo a thorough study of the karyotype or fluorescein in situ hybridization. Genetic research at the molecular level is shown to reveal the light degrees of deletion. In all cases of sporadic occurrence of aniridia, palpation of the abdominal cavity and ultrasound examination are performed every three months during the first five years of life to exclude the Wilms tumor. There are isolated reports of the family development of this tumor.

How does aniridia manifest?

Aniridia is always accompanied by a decrease in visual acuity. Patients are forced to screen the eye from excess stream of light for centuries.

Full aniridia

• The remains of the root of the iris are determined.
• Concomitant anterior polar cataract.
• Peripheral vascularized corneal dystrophy.
• Dislocation of the lens.
• Glaucoma.
• Hypoplasia of the macular area.
• Nystagmus.
• Hypoplasia of the optic nerve.
• Visual acuity fluctuates in the range of 6 / 36-3 / 60 (0.05-0.16).

Partial aniridia

Partial absence of the iris. Symptoms are the same as with full aniridia, but expressed in a lighter form. Manifestations can be hardly distinguishable, for example mild hypoplasia of the iris stroma.

Aniridia in combination with other pathology

• Gillespie syndrome, aniridia in combination with cerebellar ataxia and mental retardation.
• Aniridia in the absence of a patella.
• Other combinations.

Treatment of aniridia

In recent years, this defect has been successfully eliminated with the help of an artificial iris made of a colored hydrogel, in the center of which there is a hole 3 mm in diameter, imitating the pupil. With a one-sided aniridia, the color of the artificial iris is selected according to the color of the healthy eye.

The introduction of a prosthesis of the iris is a heavy cavity operation. To lash the prosthesis a transscleral surgical approach is necessary in diametrically located limb areas. If aniridia is combined with cataract, then it is removed and a prosthesis is substituted, which simultaneously replaces the iris and the lens.

Tactics of reference

• Refraction: often expressed ametropia.
• Appointment of spectacled and, in some cases, contact correction.
• Use of devices for visually impaired patients.
• Organization of the education system.
• The detection of glaucoma in the early stages of its development.
• Young children may need to undergo anesthesia.
• Most forms of cataract associated with aniridia do not have much functional significance, but over time, visual
  acuity may decrease due to the progression of cataracts or the development of amblyopia.