Persistent iris vessels in a case of aniridia

Congenital aniridia is caused by a mutation in the PAX6 gene [1] and is characterized by partial or complete absence of iris tissue. Apart from the hypoplasia of iris tissue, other ocular features such as foveal hypoplasia, nystagmus, aniridia-related keratopathy, Peters anomaly, Axenfeld-Rieger anomaly and glaucoma are seen in these eyes [1,2]. Cases have been reported with persistent pupillary membranes [3] and iris strands [4]. We report a case of a 27-year old female with aniridia where persistent iris vessels were noted. The vascular plexus was not visualized on slit lamp examination, however, when the patient was undergoing cataract surgery, the fragile capillaries were visualized under the operating microscope (Figure). There are few reports [3,5] of free-floating iris vessels visualized in the anterior chamber of patients with aniridia. Interestingly, similar to our case, Theobald et al [5] also noted the vascular plexus under the operating microscope. The persistent iris vessels were not visualized in the initial examination. It is important to be mindful of finding these persistent iris vessels in cases with aniridia as these capillaries are at risk of rupture and causing hyphema [5]. Although the pathophysiology remains unknown, it has been suggested that the presence of this arcade of blood vessels originating from the small iris remnants at the angle, points towards a neuroectodermal defect causing aniridia [3].