Anterior Segment Dysgenesis Syndromes

Abstract

Anterior segment dysgenesis comprises a spectrum of disorders affecting the anterior chamber structures including the cornea, iris, and anterior chamber angle. Importantly, approximately 50 % of patients with anterior segment dysgenesis will develop glaucoma. Conditions with anterior segment dysgenesis include most notably, Axenfeld–Rieger spectrum and Peters anomaly. This chapter will focus on the findings and management of patients with Axenfeld–Rieger spectrum disorders. Classic findings include an anteriorly displaced Schwalbe’s line (posterior embryotoxon), iridocorneal adhesions, and pupillary ectopia and corectopia. However, some patients may present with findings of infantile glaucoma. The condition may or may not be associated with systemic findings. Axenfeld–Rieger spectrum disorders are usually inherited in an autosomal dominant manner with disease-causing mutations in PITX2, FOXC1, and very rarely mutations in PAX6. Significant phenotypic heterogeneity is present, and severity and findings may vary significantly among family members with the same mutation. Ophthalmologic management should include maintaining a clear visual axis, monitoring closely for amblyopia, and glaucoma. Patients with anterior segment dysgenesis should be evaluated by a geneticist for evaluation of possible systemic associated abnormalities and appropriate genetic counseling.