Bilateral sporadic aniridia: review of management

Congenital aniridia: clinical profile of children seen at the University College Hospital, Ibadan, South-West Nigeria

Purpose:

To describe the clinical features of patients younger than 16 years with aniridia presenting to the Paediatric Ophthalmology unit of the Eye Clinic, University College Hospital, Ibadan, Nigeria.

Methods:

The is a retrospective review of children with aniridia seen between May 2015 and April 2019 at the Paediatric Ophthalmology unit of the Eye Clinic, University College Hospital in Ibadan. Data on demographic characteristics, presenting complaints, ocular and systemic examination findings, and interventions were collected and descriptively summarised.

Results:

A total of 28 eyes of 14 patients were studied. The mean age was 6.37 ± 4.98 years. Seven (50%) patients were male. Aniridia was diagnosed in first-degree relatives of nine patients. The most common complaint at presentation was poor vision in 11 (78.6%) patients. Objective visual acuity assessment was obtained in 22 (78.6%) eyes. Presenting visual acuity was worse than 20/60 in all 22 eyes and worse than 20/400 in 8 (36.4%) eyes. Refraction was performed in 17 (60.7%) eyes and revealed a mean spherical equivalent of −3.93 ± 5.99 diopters. Twenty (71.4%) eyes had corneal opacities, and lenticular opacities were seen in 15 (62.5%) of 24 eyes. Mean intraocular pressure (IOP) at presentation was 21.62 ± 10.4 mmHg; 12 (41.4%) eyes had elevated IOP at presentation. Ten (35.7%) eyes had cataract surgery and six (21.4%) eyes had glaucoma surgery.

Conclusion:

Familial aniridia was common in this study, and most of the patients presented with moderate to severe visual impairment. The common ocular associations were refractive error, cataract, corneal opacity and glaucoma.

Two Paired Box 6 mutations identified in Chinese patients with classic congenital aniridia and cataract

Congenital aniridia is a rare genetic disorder characterized by a variable degree of hypoplasia or absence of iris. It is frequently associated with keratopathy, cataract, juvenile-onset glaucoma and foveal and optic nerve hypoplasia. Mutations in the Paired Box 6 (PAX6) gene on chromosome 11p13 have been demonstrated to cause aniridia. The aim of the present study was to investigate the genetic variations of PAX6 in two sporadic patients from southern China with classic congenital aniridia and cataract. Complete ophthalmic and physical examinations were performed, including best-corrected visual acuity, intraocular pressure, slit-lamp examination, fundus examination, optical coherence tomography, ultrasound biomicroscopy, and Pentacam scanning. Genomic DNA was extracted from leukocytes of peripheral blood collected from the two patients, their unaffected parents and 200 unrelated control subjects from the same population. Exons 4–13 of the PAX6 gene were amplified by polymerase chain reaction and sequenced directly. Patient 1 was affected with aniridia accompanied by congenital cataract and nystagmus. A novel heterozygous PAX6 frameshift mutation c.277delG (p.Glu93SerfsX31) in exon 6 was identified in this patient. Patient 2 was presented with aniridia, congenital cataract, lens subluxation and glaucoma. A recurrent nonsense mutation c.718C>T (p.Arg240X) in exon 9 was identified in this patient. The present results expand the mutation spectrum of PAX6 and will be valuable for genetic counseling in the affected families. Additionally, the identification of these mutations reiterates the importance of PAX6 in ocular development and sheds light on the pathogenesis of congenital aniridia.

Treatment of congenital aniridia associated with subluxated infantile cataract

A 5 year old boy was presented at Eye clinic University clinical center Tuzla with congenital aniridia in both eyes. Clinical examination revealed visual acuity of 0,08 without correction in right and 0.7 with -5.0 Dsph and -1.0 Dcyl Axx 109° in left eye. Opthalmologic examination showed bilateral aniridia associated with moderate cataract in the right and incipient cataract in the left eye. In the right eye, zonular weakness with incipient capsular displacement and esotropia of Δ6º, were noted. The patient underwent phacoemulsification, implantation of capsular tension ring and Artificial Iris implant in the capsular bag. Phacoemulsification went uneventful and early postoperative recovery was successful with no signs of aniridia-associated keratopathy development and normal values of intra ocular pressure. Patient was not motivated for operation of the left eye and it was corrected with soft contact lens. Six month after the operation visual acuity in the right eye improved to 0.9 with +1.25Dsph and maintained stable in left eye, with complete elimination of esotropia and signs of binocular vision restoration. Small incision cataract extraction with IOL and Artificial Iris implantation in one procedure can be used to correct congenital aniridia and cataract with significant visual function improvement.