Ophthalmological Manifestations of Axenfeld-Rieger Syndrome: Current Perspectives

Abstract

Axenfeld-Rieger syndrome (ARS) is a rare congenital disease that is primarily characterized by ocular anterior segment anomalies but is also associated with craniofacial, dental, cardiac, and neurologic abnormalities. Over half of cases are linked with autosomal dominant mutations in either FOXC1 or PITX2, which reflects the molecular role of these genes in regulating neural crest cell contributions to the eye, face, and heart. Within the eye, ARS is classically defined as the combination of posterior embryotoxon with iris bridging strands (Axenfeld anomaly) and iris hypoplasia causing corectopia and pseudopolycoria (Rieger anomaly). Glaucoma due to iridogoniodysgenesis is the main source of morbidity and is typically diagnosed during infancy or childhood in over half of affected individuals. Angle bypass surgery, such as glaucoma drainage devices and trabeculectomies, is often needed to obtain intraocular pressure control. A multi-disciplinary approach including glaucoma specialists and pediatric ophthalmologists produces optimal outcomes as vision is dependent on many factors including glaucoma, refractive error, amblyopia and strabismus. Further, since ophthalmologists often make the diagnosis, it is important to refer patients with ARS to other specialists including dentistry, cardiology, and neurology.

Keywords: Axenfeld anomaly; Axenfeld-Rieger syndrome; Rieger anomaly; glaucoma; iris hypoplasia; posterior embryotoxon.

Figure 1

Anterior segment findings in ARS. Six eyes of patients with ARS display characteristic anterior segment findings including pseudopolycoria (A), corectopia (B–D), and posterior embryotoxon with varying degrees of iris bridging strands (arrowheads, B–E). Iris hypoplasia can appear as loss of pigment (A), gray-brown appearance (C and D), and featureless with loss of crypts, furrows, and rings (F). Glaucoma affects over 50% of individuals with ARS and elevated IOP in infants and young children can cause Haab's striae (arrows, C and F). Glaucoma drainage devices (stars, A and D) have been implanted in two of the eyes.

Figure 2

Posterior segment findings in ARS. Two eyes of patients with ARS show optic nerve dysplasia with significant peripapillary chorioretinal atrophy (A) and foveal hypoplasia (B).