Ca. Dengis et al., EGOCENTER LOCATION IN CHILDREN WITH STRABISMUS - IN THE MEDIAN PLANE AND UNCHANGED BY SURGERY, Investigative ophthalmology & visual science, 34(10), 1993, pp. 2990-2995
Purpose. Previous studies have shown that there are spatial localizati
on shifts after horizontal strabismus surgery when a patient performs
an open-loop pointing task. After monocular enucleation, an adult will
also show a shift in the pointing response. Other studies have shown
that in children who underwent enucleation, the egocenter location shi
fts toward the remaining eye. Is the pointing shift after surgery in c
hildren with strabismus the result of a shift in egocenter location? M
ethods. Using a modified Roelofs' method for measuring the egocenter,
eight children were tested before and after horizontal strabismus surg
ery to see if there were any shifts in egocenter location. One control
group consisted of six children undergoing surgery for correction of
vertical strabismus in which the horizontal muscles would be unaltered
. Results. Presurgery measurements of egocenter location in the people
with strabismus were the same as those found in the other control gro
up of 12 normal children. Postsurgical measurements of eye position sh
owed horizontal rotations of 14.5-degrees for the horizontal group and
2.4-degrees for the vertical group. Egocenter measurements showed no
postoperative shift for either strabismus group. Conclusions. Thus, th
e pointing shift seen in the previous studies is not from a shifting e
gocenter location but from a change in the registered position of the
eye in the orbit. Invest