Correspondence - ICO Library

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Binocular Vision & A Novel New [Yet Again] Procedure for Correction of FIRST Quarter of 2011
Strabology Quarterly© Com pensatory Head Posture in Infantile Nystagm us: Augm ented Anderson Plus Volum e 26 (No.1)
A M edical Scientific e-Periodical J. E. Bishop, M D Pages 37-42
augmented Kestenbaum procedure became the
standard treatment for nullpoint nystagmus.(3)
Although efficacious, the Kestenbaum
procedure has several practical problems. It
may produce overcorrections. Because
patients must chronically exert a large gaze
direction effort to hold their eyes and head
straight, some assume a head turn to the
opposite side to sustain comfortable vision.(3)
Furthermore, resections create more patient
discomfort. Theoretically, by strengthening
muscles, large resections could exacerbate
nystagmus. Because resections discard tissue,
they are inherently irreversible, and future
surgical options may be limited. Finally, the
head posture correcting ability of Kestenbaum
procedures may fade with time (3).
Independently, but also in 1953,
Anderson described recessing a medial rectus
muscle 5 mm and the contralateral lateral
rectus muscle 5 mm for correction of
horizontal head posture with nullpoint
nystagmus.(2) This approach is, in essence,
the recession half of Kestenbaum's procedure.
Because the original procedure’s ability to
correct a head turn was limited, most surgeons
perform an augmented Anderson procedure by
recessing the medial rectus muscle 7-10 mm
and the contralateral lateral rectus muscle 9-12
mm. Like the Kestenbaum procedure, the
Anderson procedure’s head posture
therapeutic effect may fade with time.
Because only two horizontal muscles are
disinserted, the Anderson procedure is
believed to damp nystagmus less than the
Kestenbaum procedure, where all four
horizontal rectus muscles are disinserted.
Large recessions of all four horizontal
rectus muscles to decrease horizontal
nystagmus was described in 1956 by Bietti.(8)
Generally, to place the new insertions behind
the equator, recession amounts are large, from
10 to 12 mm.(9,10) Although principally
employed to damp nystagmus and improve
visual acuity, Helveston has reported
correction of anomalous head posture in some
cases.(10) As the recessed muscles undergo
contracture, the effect of this operation may
fade with time.(9) Very large recessions may
be technically challenging, with re-operations
being even more difficult.(9)
In 1999, based on research in the
achiasmatic Belgian sheep dog model of
infantile nystagmus, Dell'Osso and Hertle
proposed four horizontal rectus tenotomy and
reattachment surgery to damp nystagmus. In
the same article, they also suggested that
much of the nystagmus damping effect of the
Kestenbaum procedure could be attributed to
the four horizontal rectus muscle tenotomies,
and further proposed (but presented no data)
that infantile esotropia with nystagmus could
be effectively treated by recessing both medial
rectus muscles and tenotomizing and
reattaching both lateral rectus muscles. Later
clinical studies by Hertle and Dell'Osso
11
showed improved nystagmus in adults and
children (12) following four horizontal rectus
muscle tenotomy and reattachment surgery.
Although diminished nystagmus may improve
an anomalous head posture, there are no
reports specifically employing this procedure
(tenotomy and reattachment of all
four horizontal rectus muscles) to correct
an abnormal compensatory head posture
due to nullpoint nystagmus. More recently,
in 2010, Hertle et al reported that of their
100 surgical nystagmus patients, seven were
treated with an Anderson procedure combined
with tenotomy and reattachment on the
remaining horizontal rectus muscles for head
posture correction. Three of these patients had