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Visual Physiology Service

Phone: 410-955-3560

The Visual Physiology Service at the Wilmer Eye Institute performs special tests to diagnose night blindness, color vision disorders, hereditary retinal disorders and other diseases. Often,these diseases cannot be diagnosed during routine examinations or require additional studies for the ophthalmologist to determine the correct diagnosis. For example, two tests, electroretinography (ERG) and electrooculography (EOG), help determine the extent of overall damage, the layers of retina that are damaged, and the amount of damage to these areas.

The visual evoked cortical potential (VECP) measures the electrical response of the visual cortex - the site where the brain turns nerve impulses into vision - when the retina is stimulated. This helps physicians evaluate how well the entire visual system is working, from the cornea at the front of the eye to the visual cortex at the back of the brain.

In addition, the scanning laser ophthalmoscope (SLO) is used to diagnose diseases affecting the macula, the part of the retina that is used for reading and other fine visual tasks. Using the SLO, an ophthalmologist can find the exact locations of "blind spots" in the macula that interfere with vision and can better teach patients how to use their remaining seeing retina more effectively.

Typical Conditions Seen:

Services Provided:

  • Comprehensive consultation and evaluation
  • Electroretinograms (ERG, multifocal ERG)
  • Electro-oculograms (EOG)
  • Visual Evoked Responses (VEP)
  • Color vision testing--D15, FM 100 Hue, Dark adaptated perimetry,
  • Scanning laser ophthalmoscope macular perimetry and imaging,
  • Contrast Sensitivity


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