[Aniridia syndrome: clinical findings, problematic courses and suggestions for optimization of care ("aniridia guide")]

Abstract

Background: Congenital aniridia manifests in different forms: it can be transmitted in an autosomal dominant way, as sporadic aniridia and as part of several syndromes including WAGR (Wilms tumor, aniridia, genitourinary abnormalities and intellectual disability) and WAGRO syndromes (WAGR and obesity). Furthermore, recent research shows that aniridia associated with alterations in the PAX6 gene often shows further systemic implications (e.g. endocrine, metabolic and neurological pathologies). Therefore, PAX6-related aniridia is more and more considered to be and described as aniridia syndrome or PAX6 syndrome.

Purpose: We present a group of 130 patients with congenital aniridia to enhance awareness of the complexity of the disease. Different to other congenital visual impairments aniridia is characterized by many ocular complications arising during the lifetime which may lead to total blindness (e.g. cataract, aniridic keratopathy and secondary glaucoma). Furthermore, there is a specific surgical risk entity: aniridia fibrosis syndrome and anterior segment fibrosis syndrome (ASFS) which lead to a non-infectious fibrous scarring and membrane formation of the anterior segment, often followed by hypotonia and phthisis. Aniridic glaucoma presents yet another severe complication which is often diagnosed late due to diagnostic problems and which may lead to irreversible optic nerve damage.

Discussion: The following approaches might help to improve the lifelong care of aniridia patients and might benefit the aim to lessen the impact of complications in aniridia: topical prophylaxis of aniridic corneal epitheliopathy from a very early age, regular measurement of intraocular pressure starting in young children, annual visual evoked potential (VEP) measurements and routine visual field testing as soon as possible, comprehensive optimization of surgical care independent of department location (only the very best surgeons within their subspecialty should treat the different complications) while one experienced pediatric and low vision ophthalmologist should follow the patient continuously ("aniridia guide" for the patient), thus monitoring the disease and stages of complications and advising the patient where to go for surgical treatment. This low vision ophthalmologist continuously follows the patient's course including adaptation of low vision aids according to the course of the disease, helping the patient concerning integration at school and at the place of work and advising about social and legal compensation possibilities. In addition, the guiding ophthalmologist should inform patients with aniridia about possible systemic manifestations of PAX6 syndrome concerning metabolic and neurological implications and should initiate appropriate investigations when applicable.