October
2, 2008 at 5:15 pm in Lecture Hall 3
Mina
Sehizadeh, MS, ASIP OD candidate
New
England
College of Optometry
“Monocular Adaptation of Vestibulo-Ocular Reflex (VOR)”
Abstract:
M. Sehizadeh1,
E. L. Irving1,2
1
School of Optometry, University of Waterloo, Ontario,
N2L3G1.
2
Vision Science Research Program, Toronto Western
Hospital, Ontario, Canada.
This study asks whether
active horizontal angular Vestibulo-Ocular Reflex (VOR)
gain is capable of monocular adaptation after 4 hours of
wearing 10 dioptres (D) of induced anisometropia in
healthy human adults. The participants wore a contact
lenses/spectacles combination for 4 hours. The power of
the spectacle was +5.00D (magnified images 8.65%) in
front of the right eye and –5.00D (minified images
5.48%) for the left eye, while the power of the contact
lenses was equal to the subjects’ habitual correction,
summed with the opposite power of the spectacle lens.
The VOR gain was compared between the right eye and left
eyes for trials before and after adaptation. In the
first post-adaptation trial, a significant decrease in
VOR gain (≈ 6%) occurred in the left eye in response to
the miniaturizing lens, while the right eye VOR gain did
not show a significant change (≈2% decrease). During a 2
hour follow-up time, both eyes showed a significant
decrease compared to the baseline trial. Thus, there was
monocular adaptation of VOR in response to the combined
contact lenses/spectacles,
but it was not
complete and not the expected pattern. The
results might indicate habituation of the VOR.