Figure legends
Figure 1. Panel A. The Skew VOG-Test is a portable device
consisting of a tablet screen that is mounted on the back of a bucket.
The subject is equipped with VOG googles for measuring eye position
using pupil-tracking software. Panel B. APCT: A trained orthoptist
estimated the induced skew performing the alternate cover test with
prisms opposed to the subjects left eye. The prisms were changed in
diopter size until there was no corrective vertical eye movement during
the alternate prism cover test.
Figure 2. Vertical positions of the right eye over time are
shown with black lines. Periods of right and left eye occlusions are
plotted in front of white and grey backgrounds, respectively. Curves A
to F show increasing foil strengths respectively (A 1 PD foil (0.57°),
B) 2 PD foil (1.14°) C) 4 PD foil (2.28°) D) 6 PD foil (3.42°) E) 8 PD
foil (4.56°) and F) 10 PD foil (5.70°)). Please note, that hypermetric
saccades have not been included by the VOG algorithm.
Figure 3. Correlation between the alternate cover test with
prisms (performed by an orthoptist) and VOG device (Pearson’s
R2= 0.606, p<0.05).
Figure 4. Bland-Altman plot: analysis of the agreement between
the APCT and the VOG. The difference between APCT and the VOG plotted
against the mean value for both the ACT and the VOG. The solid line
shows the mean of the differences, while the dashed lines represent the
superior and inferior limits of agreement.
Figure 5. Median prism diopters (PD) obtained by
VOG-measurement (white boxes) and by the orthoptist using APCT (grey
boxes). On the x-axis, the different FPs are given in prism diopter.