Casey Eye Institute

Usher Syndrome Type 2A (USH2A) Natural History Study

The purpose of this research study is to learn more about Usher Syndrome type 2A and Retinitis Pigmentosa caused by specific changes in the USH2A gene and how these conditions affect a person's eyes and vision. 

Eligibility criteria: 

  • Must have a clinical diagnosis of rod-cone degeneration defined as either: 
    • Usher Syndrome type 2A (with hearing loss at birth) 
    • Retinitis Pigmentosa (without hearing loss at birth) 
  • Must have at least two documented mutations in the USH2A gene 
  • Age: 8 years and older 
  • Must meet the following vision criteria:
    • 20/80 or better to be enrolled into the "primary cohort" 
    • 20/100 or worse to be enrolled into the "secondary cohort" 
  • Good general health 

Participation in the primary cohort will last 4 years and include 5 visits to the Casey Eye Institute in Portland, OR. Participation in the secondary cohort will be completed after the first visit. These visits may span 1-2 days and will include various tests to measure vision and general health. Testing includes, but is not limited to, visual function tests, dilated eye exams, ocular photography, and ERGs. All study procedures are covered by the study sponsor. 

For more information, please call the study coordinator at 503-494-0020 or send an email

Principal Investigator: Mark Pennesi, M.D., Ph.D.
Casey Eye Institute
3375 SW Terwilliger Blvd
Portland, OR 97239 

eIRB#: 17124 
IRB approve 9/26/17

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