Phenotype-Genotype Correlation in Aniridia

This study will examine specific gene changes in patients with aniridia, a disease in which the iris (colored part of the eye) is absent or partially absent, and will correlate the changes with clinical manifestations of the disease. In aniridia, the eye often appears to have no color, but only a larger than normal pupil. Patients may have impaired vision and cataracts, glaucoma, nystagmus (rapid, involuntary eye movements), photophobia (light sensitivity), displaced lens, underdeveloped retina, and thickened cornea. This study will focus particularly on corneal changes.

Patients 4 years old and older with aniridia may be eligible for this study. Candidates are screened with a family history and complete eye examination, including the following:

• Visual acuity testing using a vision chart.
• Eye pressure measurement.
• Fundus photography to examine the back of the eye: The pupils are dilated and special photographs of the inside of the eye are taken to evaluate the retina and measure changes that may occur over time. The camera flashes a bright light into the eye for each picture.
• Slit lamp examination: Evaluation of the front part of the eye with a special microscope called a slit lamp biomicroscope.
• Corneal thickness measurement.

Participants have blood drawn for genetic testing related to aniridia. Relevant medical information, including disease severity and complications, is obtained over time. Family members may also be requested to provide blood samples for genetic testing.