Aniridia
What Is Aniridia?
Aniridia is most often a genetic eye condition (either inherited or a result of a random mutation) but can be caused from an injury. It is characterized by an underdeveloped or essentially absent iris, the pigmented muscle which regulates the amount of light entering the eye through the pupil. Aniridia generally presents in both eyes.
Individuals with aniridia are likely to have one or more of the following accompanying eye issues: nystagmus (involuntary and repetitive darting of eyes), amblyopia (“lazy eye”), glaucoma, cornea scarring or other cornea issues, optic nerve hypoplasia, fovea hypoplasia, or cataracts.
While some are diagnosed with only aniridia or with aniridia and accompanying eye issues, some are diagnosed with aniridia as one component of a syndrome (set of medical issues). To learn more, read Aniridia Foundation Internationalâs description of syndromes associated with aniridia (including aniridia syndrome).
How Is Aniridia Diagnosed?
The earliest signs of aniridia are an incomplete or seemingly absent iris, light sensitivity, and nystagmusâall most often recognized in infancy. An ophthalmologist will perform a full eye exam to diagnose aniridia and any accompanying eye issues. Routine eye examinations will be required as will additional medical testing (some also performed routinely).
Genetic testing is also available to identify the type of aniridia, which helps provide information about accompanying medical conditions.
Are There Treatments for Aniridia?
There is currently no treatment for undeveloped or essentially absent irises, though there are treatments for some accompanied eye conditions.
How Would You Describe the Eyesight of One with Aniridia and How Will My Child Function with It?
Discussed below are the functional implications of aniridia; remember, however, that aniridia seldom occurs in isolation. Review the following information in addition to the functional implications of each visual condition present in your child.
With undeveloped or “nonexistent” irises, the amount of light permitted into the eye is poorly controlled or unrestrained. In effect, there will be tremendous discomfort as well as limited vision in bright light and glare.
Tinted sunglasses (often red or blue) and use of a brimmed hat will provide relief to the eyes while outdoors; individuals with aniridia may also wear slightly tinted eyeglasses to improve vision indoors. Additionally, use of non-glare surfaces (such as a chalkboard instead of a whiteboard and matte wall paint) and use of thick curtains will aid in using vision indoors.
Your child should make the most of evening outdoor exploration, play, and social activities.
Furthermore, the child will need an orientation and mobility specialist to provide instruction on using a cane (to refrain from bumping into obstacles) and using public transportation while outdoors in the daytime.
Clarity of vision varies greatly in individuals with aniridia; some are considered to have “low vision,” while others are considered legally blind (having minimal useful vision). With diminished sharp/detailed vision, it will be difficult to recognize faces and facial expressions, access information from a classroom board or wall, view a speaker or performance, read print, and perform visual tasks of fine detail such as threading a needle. In order to best use remaining vision, your family can be taught to increase the contrast of the environment. Your child may be taught to increase the contrast of print by using a CCTV or screen-magnification software, increase print size by using a hand-held magnifier and distance-vision optical device such as a handheld telescope (called a “monocular”). Furthermore, your child should sit in a preferred seat of a room for optimal viewing, generally nearer to the speaker or chalkboard.
Your childâs teacher of students with visual impairments should perform a functional vision assessment to determine how your child uses his or her vision in everyday life and a learning media assessment to determine which senses your child primarily uses to get information from the environment. These assessments, along with an orientation and mobility assessment conducted by a mobility specialist, will give the team information needed to make specific recommendations for your child to best access learning material and his or her environment.