Aniridia

 Aniridia

  • A developmental abnormality of the anterior uvea that involves multiple congenital ocular anomalies i.e. cornea, anterior chamber angle, lens, retina and optic nerve.

Clinical features:

  • Symptoms: markedly decreased visual acuity, photophobia, dry eye symptoms associated with severe ocular surface disease (eg, pain, discomfort, etc)
  • Signs:
    • Total absence of the iris is rare
    • Careful gonioscopic examination usually reveals bilateral rudimentary or hypoplastic iris tissue hidden by the limbal sclera
    • Both open- and closed-angle types of glaucoma can develop: the open-angle variant arises from a dysfunctional or absent aqueous drainage system while the closed-angle form develops secondary to blockage from the hypoplastic stump of peripheral iris tissue
    • Characteristic corneal findings include a superficial grayish haze or opacification with a circumferential corneal epithelial pannus that advances centrally
    • Other related ocular findings include: ptosis secondary to photophobia, lens subluxation, microphakia, cataract, strabismus, nystagmus, amblyopia, optic nerve atrophy or hypoplasia, and foveal hypoplasia
  • Approximately two thirds are familial in origin (autosomal dominant or recessive) and one third are sporadic
  • Recognition of aniridia at an early age is important due to the visual development significance as well as its high association with other ocular and systemic findings

Management:

  • Initial medical therapy to control intraocular pressure can be quite difficult since a significant number of patients develop refractory glaucoma
  • Glaucoma surgical procedures are frequently necessary in patients who develop refractory glaucoma
  • Treatment of photophobia and nystagmus
  • Cataract surgery should be approached with caution because of accompanying zonular dehiscence and/or lens subluxation
  • Progressive pannus involving the entire cornea may necessitate penetrating keratoplasty
  • Genetic counseling