Related Experiment Videos
Detection of localized retinal dysfunction in a choroideremia carrier
Marsha C Cheung1, George C Nune, Min Wang
1University of California School of Medicine, San Francisco, California 94143-0730, USA.
American Journal of Ophthalmology
|January 1, 2004
Summary
Choroideremia carriers can experience severe vision loss due to mosaic gene inactivation. Multifocal electroretinogram (mfERG) effectively detects functional abnormalities in these carriers.
Area of Science:
- Ophthalmology
- Genetics
- Medical Imaging
Background:
- Choroideremia is an X-linked genetic disorder causing progressive vision loss.
- Carriers of choroideremia typically have milder symptoms, but severe unilateral vision loss can occur.
Observation:
- A case report detailing a choroideremia carrier presenting with severe unilateral vision loss.
- The study involved ocular examination, genetic testing, Humphrey visual fields, and electroretinogram (ERG) tests.
Findings:
- Multifocal electroretinogram (mfERG) revealed significantly reduced amplitudes in the affected eye.
- Correlation observed between mfERG findings, retinal pigment epithelial and choroidal atrophy, and dense central scotoma on visual field testing.
- Decreased full-field ERG amplitudes were also noted.
Implications:
- Multifocal ERG (mfERG) demonstrates sensitivity in quantifying functional deficits in choroideremia carriers.
- Mosaic inactivation of the CHM gene may lead to the expression of the mutation, resulting in severe vision loss in carriers.