Strabismus - Fundamentals of Clinical Ophthalmology.pdf

STRABISMUS
overacting in a V pattern. If there is no
oblique overaction, transpose the horizontal
recti, the medial recti to the apex of the
pattern, and the lateral recti to the base.
4. Oblique surgery in the adult is less forgiving
than in the child.
(a)
(b)
Figure 7.11 Underaction of left superior oblique in
child with left coronal synostosis. Tightening superior
oblique tendon laxity improved field of binocular
single vision with improved ocular posture without
an acquired Brown’s syndrome. (a) Preoperative.
(b) postoperative
Adjustable sutures
Adjustable sutures increase the chance of
ideal surgical alignment with one operation,
decreasing the need for reoperation or staged
repairs. More sophisticated surgical techniques
and materials have stimulated their increased
use. Different techniques involve two-stage
procedures where the final alignment is achieved
postoperatively with external sutures, or the
procedure completed with the patient awake. 17
In our experience, using adjustable sutures has
led to better judgement in the operating room,
leading to a minority of patients needing further
postoperative adjustment (Figure 7.12).
preferred to superior oblique tucks. In neurogenic
cases ipsilateral superior rectus recession is useful
where a long-standing superior oblique palsy has
resulted in tightness of the tendon of the superior
rectus. The superior oblique tightening procedure
(Harada–Ito) is our preferred option where
torsion is the main problem.
Summary of management
of A and V patterns
1. Observe the vertical movements of the eyes
with accommodation controlled, preferably
doing the test at distance and asking the
patient to maintain fixation by depressing
and elevating the chin. The eyes will move in
the opposite directions and measurements
can be made.
2. Consider whether the pattern is severe
enough to treat.
3. Operate on the superior obliques if overacting
in an A pattern and inferior obliques if
Botulinum chemodenervation
Studies have shown botulinum toxin to be
helpful in small to moderate esotropia and
exotropia (less than 40 D), active thyroid disease
if surgery is inappropriate and postoperative
residual strabismus after several weeks. There
has been less evidence for use in A and V
patterns, DVD or oblique muscle disorders.
Success has ranged from 30% to 70% depending
on the size of deviation. 18
Sequelae and complications of
strabismus surgery
Anaesthesia
In early childhood, an anaesthetist well
experienced in paediatric anaesthesia is
essential. Usually day surgery is all that is
required. Children need to be prepared for
hospital, to have their favourite toy with them
and to have their parents with them during
86