The introduction of perimetry into medicine: von Graefe and the
campimeter 1856
Von Graefe (right) is credited with introducing perimetry into clinical
medicine. In 1855, at the age of 28, he published "Examination of the Visual
Functions in Amblyopic Affections." Von Graefe built on the work of
Helmholtz. Helmholtz had recommended that, in order to keep one’s bearing
during the examination of the ocular fundus, a numbered grid be placed in
front of the patient to direct the patient’s eye into certain known
directions of gaze. It was a piece of blackboard marked in this way that von
Graefe used as a tangent screen. He worked at a distance of 18 inches and
used as a test object a piece of white chalk, about 1 cm across, held in a
wire. He made use of various symbols and dots as a fixation point so that
the patient could recognize his deficits more easily.
It was clear from this classic article that von Graefe had been plotting
visual fields on almost everybody for some years.
He gave examples of ring scotomata, concentric constriction of the
visual field, enlargement of the blind spot, and homonymous, bitemporal, and
binasal hemianopia. He suggested that homonymous hemianopias were caused by
unilateral cerebral disease and heteronymous hemianopias by growths at the
base of the brain. This seminal work is responsible for establishing
visual-field testing equipment in the ophthalmologist’s clinic.
Schiefer
has developed a perimetry pedigree that can be used as a guide as we go through
perimetry history after Von Graefe. (Please be patient, the
file is large and may take a minute to load.)
