Presenter: Melanie Hingorani MA MBBS FRCOphth MD, Consultant ophthalmic surgeon and ANUK Medical Adviser
Aniridia is one of the Anterior Segment Developmental Abnormalities (ASDA). The classic feature is of a reduction in iris tissue, ranging from almost complete lack of iris to full iris within thinner and abnormal tissue structure. However the disorder affects the eye from front to back and a particular feature is a reduction in the definition and structure of the fovea (foveal hypoplasia), the central part of the retina which is responsible for providing central detailed vision. Many have significant visual impairment but milder cases in whom the fovea is normal may have good vision. There are a number of progressive or later onset features of the condition which can cause further visual deterioration or complications, which are cataract (cloudy lens), glaucoma (raised eye pressure damaging to the optic nerve) and keratopathy or corneal disease (scarring and new blood vessels growing over and clouding the clear front “window” of the eye). Once the diagnosis of aniridia is made, patients are monitored throughout life to detect and treat these later problems.
Therapy can be divided into non-surgical and surgical types. A large part of therapy is supportive, involving providing the appropriate visual aids (glasses, contact lenses, low vision aids, tinted or
photochromic lenses for glare) and educational, work and social support. Patients may also require drops for glaucoma and to control corneal symptoms. Most patients do not need surgery, but
some may require operations for ptosis (droopy lids), squint (misaligned eyes), cataract, glaucoma, keratopathy and also complications of surgery such as the rare aniridic fibrosis syndrome or for retinal detachment. Very occasionally operations are undertaken to try and restore the pupil appearance or glare-reducing function of the missing iris. The reasons for requiring surgery and the details of the various surgical options are described in the talk along with complications which can occur and also the particular sorts of risks/complications of such procedures in those with aniridia.