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