Dissociated vertical deviation (DVD)
Dr Sudhir Singh,MS
DVD was described in George Stevens in 1895.He
atributed"alternating vertical strabsmus".
Dissociated vertical deviation (DVD) is a poorly
understood vertical deviation which may remain latent
(compensated) or manifest (decompensated). The deviation
may be symmetrical or asymmetrical, and small or very
large, measuring more than 20 prism diopters.
The dissociated eye not only elevates but excycloducts.
When the fellow eye is covered, the dissociated eye
returns to primary position with a corrective
incycloduction movement.
With bilateral DVD either eye moves down to refixate
after removal of the cover. The condition is bilateral
in most instances but most often asymmetric in
magnitude.
DVD may occur alone or in combination with a true
hyperdeviation.
Unlike in paralytic vertical strabismus, the degree of
elevation of the dissociated eye is often the same,
regardless of whether the eye elevates from adduction,
primary position, or abduction.
If neutral
filter is placed before one eye while the other eye is
occluded, the eye behind the cover makes a gradual
downward movement as the density of the filter is
increased in front of the fixating eye (Bielschowsky
phenomenon).
Surgical Treatment :
large superior rectus recession that is usually bilateral.
When DVD is associated with inferior oblique overaction,
anterior transposition of the inferior oblique is effective.
Inferior rectus resection may be done as a secondary
procedure.
Unilateral Surgery (If
vision is not equal due to residual amblyopia, one can
do unilateral surgery in the amblyopic eye}
DVD
(in Prism Diopter)
Superior Rectus Recession
10 pd
5 mm
11-15 pd
6 mm
16-20 pd
7 mm
21-25 pd
8 mm
> 25 pd
9 mm
Bilateral Surgery
(If vision is equal, you
should do bilateral surgery)
