An improved method of fitting resultant prism in treatment of two-axis strabismus
R. D. Reinecke, K. Simons, A. Moss and G. Morton
A new chart determines resultant prism power and angle when correction of
combined horizontal and vertical deviation with a single prism, set at an
angle intermediate between horizontal and vertical, is desired. The chart
is based on a derivation so weighted as never to permit a vertical error
greater than one tenth as large as the associated horizontal error, with
use of commercially available sizes of plastic Fresnel-type prisms. This
weighting takes into account differences in horizontal and vertical
fusional reserves. A compass rose facilitates proper alignment of the
prisms.
