Aniridia in the Newborn Treatment & Management

Updated: Apr 06, 2017
  • Author: Sophie Bakri, MD; Chief Editor: Donny W Suh, MD, FAAP  more...
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Treatment

Medical Care

Medical management of glaucoma associated with aniridia

Medical therapy of the glaucoma is the initial treatment of choice. It initially may be efficacious in reducing intraocular pressure, but most patients with aniridia who have glaucoma eventually require surgical therapy.

Miotics often are tried first; they improve aqueous outflow by contracting the ciliary muscle. However, the induced myopia may not be well tolerated by young patients. Adrenergic agonists, beta-blockers, and carbonic anhydrase inhibitors also may be tried, but they often are ineffective long term as the patient becomes refractory to them. Whenever a new medication is to be instituted, a trial should be performed, adding and removing only one medication at a time.

Optical correction

Patients with aniridia may be emmetropic, myopic, or hyperopic. Spectacle or contact lens correction of significant refractive errors should begin in the newborn. In cases of lens subluxation, the refractive error should be corrected through the aphakic portion of the pupil.

To lessen photophobia, patients may be fitted with tinted or iris contact lenses or with tinted spectacle lenses at any age.

Treatment of amblyopia and strabismus

In cases of strabismus, patching of the favored eye is indicated to treat amblyopia. Cycloplegic refraction should be performed, and appropriate correction should be given. Strabismus surgery may be indicated at an early age to enhance binocularity.

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Surgical Care

No convincing opinion exists as to which surgical procedure is the treatment of choice for aniridic glaucoma; none has been considered reliable and predictable in efficacy. Surgical procedures for the treatment of aniridic glaucoma include the following:

Goniotomy

Although goniotomy has been suggested early in the management of aniridic glaucoma, reported series have shown disappointing results. The procedure is hazardous in these eyes, since the Barkan goniotomy knife is passed over the vulnerable lens and zonules in the anterior chamber. However, results of prophylactic goniotomy have been encouraging.

Two separate surgeries on each eye may be performed to strip the tissue extending over the trabecular meshwork, working on 180° of the angle each time. The benefit of this prophylactic procedure is not yet proven, and it should be delayed until after the first year of life. Because of the shallow anterior chamber angle, patients with aniridia should have gonioscopy performed yearly. If the iris processes are becoming more prominent, strong consideration should be given to performing a prophylactic goniotomy.

Trabeculotomy

This procedure is considered safer than goniotomy, since it relies on the posterior approach (ab externo), which avoids the lens and zonules. However, it is not without risk and has been associated with the need for repeat surgery.

Trabeculectomy

Most surgeons opt for trabeculectomy after a few attempts at goniotomy or trabeculotomy. However, the risk of vitreous loss is increased in aniridia, and cataract formation or progression may occur with inadvertent damage to the lens during surgery. Nelson et al reported that 5 of 14 patients needed reoperation or had failure with trabeculectomy [3] ; others have reported initial success rates from 0-9%.

Setons

The success rate of the Molteno implant has been reported as 83% of 6 eyes. This device cannot be recommended as the initial operation of choice because of the higher risk of complications.

Cyclophotocoagulation and cyclocryotherapy

Both these modalities are designed to destroy part of the ciliary body. Cyclophotocoagulation is performed with the yttrium-aluminum-garnet (YAG) laser. Both methods must be split into multiple treatment sessions to avoid complications, such as uveitis, phthisis bulbi, uveal effusion, vitreous hemorrhage, and prolonged hypotony. Cryotherapy may accelerate peripheral corneal opacification or cataract progression. Therefore, these procedures must be approached with extreme caution, and they have been associated with hypotony and vitreous hemorrhage.

Cataract extraction

When the cataract is dense, removal may result in some improvement in visual acuity. Lensectomy performed with an aspiration-cutting instrument has been recommended. Capsule-supported intraocular lenses are not appropriate for patients with ectopia lentis.

Penetrating keratoplasty

This may be indicated for corneas that have opacified from pannus. However, the prognosis is guarded because of rejection and underlying amblyopia or other structural defects.

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Consultations

Genetic counseling

All patients with aniridia should be referred for genetic counseling. A full family history should be sought, with specific attention to ocular abnormalities, low vision, genitourinary abnormalities, Wilms tumor, and mental retardation.

A full physical examination should be performed concentrating on the genitourinary system. Imaging of the abdomen and brain, preferably MRI, is indicated.

Chromosome analysis of the patient and family members and genetic analysis of the PAX6 gene should be performed.

Parents and close relatives should have a careful ocular examination performed.

Fluorescein angiography of the iris and fundus may reveal subtle abnormalities not found clinically, for example, abnormalities of the iris collarette and foveal avascular zone.

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