Aniridia

Definition

In Aniridia, the iris is either underdeveloped or absent.  The iris is the colored part of the eye so when it is absent the pupil  appears to be very large.  However, the abnormal pupil is not the reason for the most significant reduction in vision.  Instead, the underdeveloped optic nerve or macula, at times associated with cataract and glaucoma, are the causes of visual loss.

Aniridia is present at birth and usually affects both eyes. Aniridia is usually considered a genetic condition. However, about a third of the time, there is no family history of the condition (Aniridia Foundation International). Therapy is less directed towards the iris or papillary anomaly but instead towards the associated conditions, optic nerve hypoplasia, cataract, glaucoma, and macular hypoplasia.

 

Functional Characteristics

Individuals with Aniridia may struggle with photophobia (sensitivity to light) that can be helped with tinted lenses or sunglasses. Other characteristics include decreased visual acuity and nystagmus (involuntary eye movements). Vision can vary depending on lighting conditions and focusing difficulties. Providing controlled environments and adaptations, where possible, can he helpful in maximizing vision.

 

Examples include:

  • Adaptive lighting to reduce glare (controlled dim lighting, avoid looking into light source)
  • Magnification or enlargement
  • Occasional breaks to prevent visual fatigue
  • Sunglasses
  • Services of a Teacher of the Visually Impaired for adaptations and evaluation of vision related technology that can enhance learning.

 

Associated Conditions

Providing controlled environments and adaptations, where possible, can be helpful in maximizing vision.

All cases of Aniridia should be evaluated for WAGR Syndrome; otherwise known as 11p Deletion Syndrome (Int’l WAGR Syndrome Assoc.)

 

WAGR Syndrome is rare and stands for:

  • (W)ilms Tumor-malignant kidney tumor that usually appears before age six
  • (A)niridia
  • (G)enital/Urinary abnormalities
  • (R)etardation

Glaucoma is a secondary condition to Aniridia. The intraocular pressure from glaucoma can cause pain and cornea cloudiness as well as lead to visual field loss. Other conditions that are rare are sometimes present with a diagnosis of aniridia include cataracts, lens opacities, optic nerve hypoplasia and macular hypoplasia.

 

Resources

 

Aniridia Foundation Int’l Information, 

Conferences, Support, Research

Free Membership & Newsletter

http://www.aniridia.net
E-mail: info@aniridia.net

 

Aniridia Network Int’l Online discussion group for families/individuals  & Annual Meetings

http://www.aniridia.org.uk/
E-mail  hannah@aniridia.org

 

Family Connect

A website for parents of children with visual impairments developed by American Foundation for the Blind and National Association of Parents of Children with Visual Impairments

www.familyconnect.org

 

International WAGR Syndrome Association

http://www.wagr.org

 

Delta Gamma Center for Children with Visual Impairments    

1750 S. Big Bend Blvd.

Richmond Heights, MO  63117

(314)776-1300

www.dgckids.org

 

Acknowledgments

Delta Gamma Center for Children with Visual Impairments acknowledges the following sources of information for this summary:

Aniridia Foundation International. Aniridia Information. Retrieved November 24, 2010, from http://www.aniridia.net/infomenu.html

Eye Conditions & Syndromes & Other Conditions. Project VIISA; SKI-HI Institute

International WAGR Syndrome Association. Retrieved March 8, 2011, from http://www.wagr.org

Professional Edit, Steven D. Goodrich, M.D. Pediatric Ophthalmologist

 

 


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