the mother of this 4 years old child noted
that there is inward eye deviation and sometimes the Rt. eye drifts
up. The condition started 2 years ago,
examination showed bilateral normal fundi and
bilateral emmetropia.
See video of this patient
Dissociated Vertical Deviations ( DVD )
Dissociated vertical deviation (DVD)
is a recognised association of congenital
esotropia.
Dissociated vertical deviation (DVD) is the
most least understood of all
forms of strabismus. DVD is totally different from
hypertropia. In a
patient with right hypertropia, either the right
eye is elevated when the left eye is fixating or
the left eye is depressed when the right eye is
fixating. While, in DVD, either eye
elevates when the fellow eye is fixating.
Moreover, the deviation does not always
alternate but may be restricted to one eye.
DVD is characterized by elevation of either eye
when the patient is fatigued or daydreaming or
when fusion is interrupted by covering one eye. When
the cover is removed, the elevated eye will move
slowly downward and settle in the primary
position. The amount of elevation when the eye
is covered is variable, tending to increase
after prolonged occlusion, and often differing
between the two eyes.
Other
features may be present with DVD, these include extorsion of the
elevated eye and intortion of the
fixating eye,
when the elevated eye
returns to the primary position it intorts.
Observation of the conjunctival vessels will nearly
always reveal intortion as the elevated eye
returns to the midline.
One of the disorders which
is commonly mistaken as DVD is the inferior
oblique overaction,
DVD must be
distinguished from inferior oblique overaction
(IOOA). IOOA causes a V pattern and if no V
pattern is seen, the diagnosis is purely DVD.
Excyclotorsion is an important aspect of DVD and
not seen in pure IOOA. VD. Finally,
in case of IO overaction elevation of the eye occurs only
during adduction while in DVD elevation of the
eye occurs during adduction, abduction and
primary position.
Therapy
Patients with DVD are usually asymptomatic, however,
when the patient is daydreaming or fatigued, the
elevated eye may become a source of embarassment
to the patient. In that case surgery may be
considered. Personally I have not observed DVD
in adults as often as in children, I share many authors that
DVD tends to improve with time.
Surgical procedures for DVD are :
(1) Recession of the SR
combined with resection of the IR
(2)
Resection of the IR
(3)
Retroequatorial myopexy (posterior fixation) of
the SR muscles combined with or without a
recession of these muscles.
(4) Large recessions (7 to 10 mm) of th
e
SR.
(5 )
Anterior displacement of the IO insertion, which
may be combined with SR
recession.
The debate about whether surgery should be
performed in both eyes in cases of unilateral
DVD. It is not
uncommon and quite disappointing to have a
patient return after surgery in one eye with a
DVD in the fellow eye. However, since in my experience this does not happen in every
case of unilateral DVD, I operate
on both eyes only when a DVD is present in both eyes.
الموقع المصري للحول
وامراض الجهاز الحركي للعين
The Egyptian Site of
Strabismus & Oculomotor Disorders
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