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12 paź 2019 · An instructional video on how to carry out a visual field test utilising the Bjerrum Tangent Screen. *Do not own any music included in the video, they belong...
Bjerrum felt that mapping the subtleties of the central 30° was far more useful than the routine outlining of the perimeter of the visual field that was commonly being done. He is said to have scorned the available perimetric instruments and mounted a tangent screen on the back of his office door.
Several targets of varying sizes on the wand were tested, effectively mapping the variation in size required for vision in different areas of the field. This method of testing, known as the tangent screen, only measures the central 30° of the visual field [5].
Historical Significance: This apparatus, known as a tangent screen or a Bjerrum screen, is for locating and measuring blind areas in the central 30 degrees of the visual field.
Bjerrum’s Chart (Tangent Screen) Bjerrum screen helps to find the central visual field defect.
Other Test Names: Bjerrum Screen or Tangent Screen. ription of the test. The tangent screen test includes a black felt screen with a pattern of radians and circles sewn in black with a white button in the center, a black wand, a supply of black pins, a selection of targets, an occlude. , and a score sheet. A chin rest is also rec.
Tangent screen testing uses a flat testing surface and is useful for testing the central visual field, but for testing beyond 30° its value is limited (Figure 7). The tangent screen is usually a black felt screen mounted on a wall and testing is performed while the patient is sitting down.
