Electrodiagnostic and Vision Functions Clinic

General Information

The Electrodiagnostic & Vision Functions Clinic (VFC) is a patient care clinic through which third year interns rotate. General ophthalmologists, retinal ophthalmologists, neuro-ophthalmologists or optometrists refer most patients.

• Referrals to the Electrodiagnostic & VFC are generally for patients requiring:
  • Confirmation of diagnosis due to clinical findings or symptoms suggestive of known ocular disorders.
  • Explanation of vision loss, either visual acuity, fields, color vision, or other symptoms.
  • Pediatric neuro-ophthalmic examinations – particular indications are congenital nystagmus, oculodigital sign, high refractive error, or sluggish pupil responses associated with visual inattentiveness.
  • Monitoring of ocular health due to retinotoxic medications, e.g. hydroxychloroquine, thioridizine, quinine.
  • Quantitative assessment of progression of eye disorders.
  • Evaluation of retinal function to identify high risk from retinal ischemia, e.g. in central retinal vein occlusion and diabetes.
  • Color vision and visual performance assessment for vocational purposes.
  • Appointments for other reasons, including research, normative data collection, or recall for teaching purposes.
• Tools for testing vision function:
  • Electrodiagnostic tests:
    • Ganzfeld ERG
    • Pattern ERG
    • Focal ERG
    • Multifocal ERG
  • Electrooculogram (EOG)
  • Visual evoked response (VER)
• Psychophysical tests:
  • Goldmann perimetry
  • Dark adaptation
  • Contrast sensitivity
  • Glare testing
  • Low luminance visual acuity
  • Color testing including
    • Anomaloscope
    • Farnsworth-Munsell 100 hue test
    • Farnsworth Lantern test
    • Achromatopsia tests
    • Pseudoisochromatic plates tests

A diagnosis is frequently based on the pattern results from a subset of the above tests. This Clinic emphasizes the use of primary care tools such as history, visual acuity, funduscopy, confrontation visual fields, pupil testing, red cap testing, Amsler grid testing, etc., as essential adjuncts to the more specialized tests.

The goals for your exposure to this Clinic are:

• To learn about clinical application of electrodiagnostic and advanced psychophysical testing.
• To learn the essential information that each test provides.
• To learn to identify which patients should be referred for specialty testing, and which tests are most appropriate.
• To broaden your exposure to ocular pathology by working with patients with rare or interesting disorders. Many patients have retinal dystrophies that are rarely seen outside a referral center.