Congenital aniridia: an epidemiological approach on 105 patients

PurposeAniridia is a rare ocular disorder affecting beside iris, cornea, angle structures, lens and fovea, and possibly associated with other anomalies. This study aims at understanding features of patients with congenital aniridia, identifying the characteristics phenotypes of the disease and its associated anomalies.MethodsPatients affected by congenital aniridia were prospectively included and clinically examined at two french pediatric reference centers, with local ethics committee approval. Following parameters were assessed: sex ratio, sporadic or familial history, associated eye anomalies (glaucoma, limbal deficiency, cataract).ResultsThe study included 105 patients of the 135 registered at Ophtara Rare Disease Center with CEMARA data basis. The median age at last examination were 10 years old (3 days; 75 years) with a 65% rate and a mild female predominance (sex ratio 0.65). All patients had bilateral aniridia, with a remaining iris insertion uni or bilateral in 32 patients (30.5%). Thirty patients had a familial form of aniridia (28.6%). Aniridia was isolated in 94 p. (89.5%), and associated with 7 WAGR syndromes, one WAGRO syndrome, one Gillespie syndrome. Cataract was described in 51 patients (49%) – bi (41%) or unilateral (8%) –, limbal deficiency in 59 p. (56.2%), and glaucoma in 45 p. (42.9%). A mutation of the PAX6 gene was registered in 23 p. (21.9%), with no obvious genotype‐phenotype correlation. In absence of iris insertion, the relative risk of glaucoma was assessed at 1.6 (IC 95% [1.03; 2.58]).ConclusionsThe aniridia phenotype characteristics varies widely. Risk factors for glaucoma/limbal insufficiency have to be better defined by further studies and a standardization of the flow charts clinical elements to collect should provide better insight in further congenital aniridia data collection.