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Ophthalmology
Published in Stephan Strobel, Lewis Spitz, Stephen D. Marks, Great Ormond Street Handbook of Paediatrics, 2019
All children with sporadic aniridia should have repeated abdominal ultrasonographic and clinical examinations; molecular genetic evaluation reveals intragenuc mutation only. One protocol advised that the child be seen every 3 months until the age of 5 years, every 6 months until the age of 10, and once a year until the age of 16. If chromosomal deletion is found, 3-monthly scans should be performed and the child transferred to the care of a nephrologist. 50% of patients with aniridia may develop glaucoma and nearly all will develop a keratopathy in adulthood due to limbal stem cell deficiency.
Pediatrie genitourinary oncology
Published in J Kellogg Parsons, E James Wright, The Brady Urology Manual, 2019
Jennifer Miles-Thomas, Matthew E Nielsen, Caleb P Nelson
Sporadic aniridia: Incidence in general population: 1/50 000 birthsIncidence in Wilms’ tumor: 1/70 cases (1.1%)Patients with aniridia have a 33% risk of developing Wilms’ tumor.
Management of hyphema, repair of iridodialysis, and repair of corneoscleral lacerations
Published in A Peyman MD Gholam, A Meffert MD Stephen, D Conway MD FACS Mandi, Chiasson Trisha, Vitreoretinal Surgical Techniques, 2019
For patients with a complete iridodialysis (aniridia), options are limited. One option is a contact lens with an occluding outer annulus. Although currently not available in the USA, diaphragm intraocular lenses have been developed for the correction of aniridia, and these lenses have recently been placed in traumatic cases.12–;14 The lenses can be placed in the sulcus, in the capsular bag, or with transscleral fixation. The studies to date have short-term follow-up, but suggest that visual acuity and glare symptoms improve, and the lenses are well tolerated.
Ocular manifestations of systemic diseases in children
Published in Clinical and Experimental Optometry, 2023
Cheefoong Chong, Ann L Webber, Shuan Dai
Aniridia is a rare congenital ocular disorder, which affects not only the iris but the entire eye. The term aniridia suggests absence of iris, but in fact, the iris may be partially absent or hypoplastic. In children where the iris appears completely absent, the iris root is always present. Aniridia is often associated with PAX6 gene mutation and is inherited in an autosomal dominant fashion. This gene is a transcriptional regulator and is crucial for development of the eye. Adjacent to the PAX6 gene is the WT1 gene, which is a tumour suppressor gene. Mutations of the WT1 gene causes Wilms tumour/nephroblastoma. Due to the proximity of both genes, 25–33% of aniridic patients will develop nephroblastoma before 3 years of age.33 These children will often have other associated diseases including genitourinary anomalies and mental retardation.
Corneal transplantation in children - when and how?
Published in Expert Review of Ophthalmology, 2023
Abha Gour, Aastha Garg, Shailja Tibrewal, Julie Pegu, Sonal Gupta, Umang Mathur, Virender Sangwan
Mutations in the PAX6 gene [43] are responsible for the partial or complete absence of the iris tissue along with multiple associated comorbidities like aniridia-associated keratopathy (AAK), which involves central corneal opacity along with associated limbal stem cell deficiency [44]. Aniridia is also associated with cataracts, glaucoma, macular hypoplasia and amblyopia. Keratoplasty for congenital aniridia is rarely required as patients maintain stable vision in the early years; however, vision further deteriorates with progressive keratopathy. Full-thickness keratoplasty in isolation has a poor prognosis due to the associated limbal stem cell deficiency (LSCD) and vascularization; endothelial keratoplasty and keratoprosthesis for aniridia have also been reported [45,46].
Genetic causes of nystagmus, foveal hypoplasia and subnormal visual acuity- other than albinism
Published in Ophthalmic Genetics, 2021
Miriam Ehrenberg, Laura Bagdonite-Bejarano, Anne B. Fulton, Naama Orenstein, Claudia Yahalom
Defects in the PAX6 gene affect embryonal eye development and result in a range of clinical phenotypes, the most common being aniridia, a panocular disorder characterized by iris hypoplasia combined with foveal hypoplasia. Aniridia is associated with other, typically later-onset ocular abnormalities, including cataract, glaucoma, and keratopathy (16). Infrequently, deletions present both in the PAX6 and its neighbor gene WT1. The resultant phenotype, known as WAGR syndrome, is characterized by a life-threatening kidney tumor, in addition to the abovementioned ophthalmic findings. Hence, early identification of this gene mutation is important. Milder forms of PAX6- related eye disease have been described (17). These are noted by only mild anterior segment dysgenesis such as corectopia (accompanied by foveal hypoplasia and nystagmus), isolated transillumination defects or even by only isolated foveal hypoplasia and nystagmus (17,18). In our study, 33% of the individuals in the PAX6 group had corectopia as the sole anterior segment sign. The others had additional anterior segment dysgenesis such as cataract or iridolental strands. These helped lead to the suspicion of PAX6 as the causative gene. Though mild, the anterior segment changes prompted the treating clinicians to sequence the PAX6 genes before broadening the work-up with an ERG exam. This may explain the significantly lower proportion of patients in the PAX6- group that had undergone an ERG exam: 20% compared to 71% of those in both SLC38A8 and diverse gene mutation groups.