The Science behind the Tip
Congenital aniridia is a rare bilateral developmental disorder which is inherited in an autosomal dominant fashion in approximately two thirds of cases; the remainder occur sporadically. Glaucoma appears in late childhood or adolescence, when progressive changes occur in the drainage angle and occurs in 50-75% of affected individuals (1). The condition is often associated with other ocular defects (corneal disease, cataract formation and foveal hypoplasia) and some forms are linked to systemic disease (e.g. Wilms tumour) (2).
Medical therapy is inadequate in most cases and trabeculectomy does not lead to long-term control of the IOP because of bleb failure secondary to scarring and progressive changes in the angle. Tube-shunt surgery appears to offer good results one year after surgery (3,4). The long-term results of this surgery have not been reported.
Contributor: John F Salmon MD - Oxford
References
Grant WM, Walton DS. Progressive changes in the angle in congenital aniridia, with development of glaucoma. Am J Ophthalmol 1974; 78: 842-847.
Elsas FJ, Maumenee IH, Kenyon KR et al. Familial aniridia with preserved ocular function. Am J Ophthalmol 1977; 83: 718-724
Arroyave CP, Scott IU, Gedde SJ et al. Use of glaucoma drainage devices in the management of glaucoma associated with aniridia. Am J Ophthalmol 2003; 135: 155-159.
Almousa R, Lake DB. Intraocular pressure control with Ahmed glaucoma drainage device in patients with cicatricial ocular surface disease-associated or aniridia – related glaucoma. Int Ophthamol 2014; 34: 753-760.
Tip Reviewer: Roger Hitchings
Tip Editor: John Salmon