Avoiding Complications of Inferior Oblique Muscle Surgery

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Avoiding Complications of Inferior Oblique
Muscle Surgery

• Kenneth W. Wright, MDLos Angeles, California

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35 yo diplopia after 2 surgeries for L-HT 2nd to
left cong. SOP Done Elsewhere
2nd Surg Advance Right IR

• 1st Surg
• L-IO anteriorization
• Right IR recession

• Overcorrection

• Still overcorrected
• R-HT 6
• Diplopia for gt1 yr

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Diplopia after left IO anteriorization worse in
up gaze-
RHT 6 - 18
RHT 2 - 10

• RHT 6 XT6

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Time of surgery- IO found on the IR insertion
J deformityAnti-Elevation Syndrome
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Post operative improvement of elevation after
inferior oblique was moved 5 mm posterior to the
inferior rectus insertion

• Anti-elevation looks like Un-masked SOP

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Anterior placement of posterior fibers (J
Deformity)Can cause Anti-Elevation Syndrome

• Inelastic neuro-vascular bundle acts as muscle
  origin
• Anterior IO is now a depressor and pulls the eye
  down

David Stager MD AOS-2000
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How to avoid limited elevation

• Keep the posterior fibers posterior - avoid the
  J deformity
• Avoid placing the IO anterior to inferior rectus
  insertion
• Do not resect muscle

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Graded AnteriorizationMore anterior - more
weakeningWright 1991 Atlas of Strabismus Surgery

• Maximum effect - At inferior rectus insertion
• Least effect 4 mm posterior to inferior rectus
  insertion

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Results of Graded Anterior Transposition

• 18/21 patients normal versions All lt 1
• Full anteriorization for congenital SOP mean
  change 18 PD
• No anti-elevation postoperatively

Guemes A, Wright KW. Effect of graded anterior
transposition of the inferior oblique muscle on
versions and vertical deviation in primary
position. Journal of AAPOS, Aug 1998, pp
201206.
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Inferior Oblique OveractionWright Graded
Anteriorization

• Pre-op 3 IOOA Post -op No IOOA

Guemes A, Wright KW. Effect of graded anterior
transposition of the inferior oblique muscle on
versions and vertical deviation in primary
position. Journal of AAPOS, Aug 1998, pp
201206.
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Hooking the Inferior Oblique Muscle

• Split Muscle - undercorrection
• Vortex vein - hemorrhage
• Tonic pupil cilliary ganglion

KW Wright Atlas of Strabismus Surgery 2007
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Avoid split muscle by direct visualization of
Posterior boarder of inferior oblique muscle
KW Wright Atlas of Strabismus Surgery 2007
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Split Inferior Oblique Muscle
KW Wright Atlas of Strabismus Surgery 2007
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Dissection of fascia can cause fat adherence

• Violation of Tenons capsule causes orbital fat
  to scars to muscle or sclera

KW Wright Atlas of Strabismus Surgery 2007
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Avoiding Fat AdherenceKeep dissection close to
muscle - avoid orbital fat
KW Wright Atlas of Strabismus Surgery 2007
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After hooking the inferior oblique pull fat off
the hook
Open the intermuscular septum at the muscles
edge
KW Wright Atlas of Strabismus Surgery 2007
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Remove intermuscular septum cutting close to the
muscle Avoid cotton tip dissection
KW Wright Atlas of Strabismus Surgery 2007
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Suturing the muscle

• Scleral perforation
• Inadvertent resection

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Suture over the Wright hookorClamp the muscle
then remove and suture off the sclera
Do not inadvertently resect the muscle
KW Wright Atlas of Strabismus Surgery 2007
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Full anteriorization can also cause lid fissure
narrowing IO anteriorization left eye
Lid Fissure Narrowing Recession none At IR
insertion 1 mm 2 mm ant to IR 2 mm Kushner Ach
ophthal 2000
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Summary - Inferior Oblique Surgery

• Dissect close to the muscle avoid fat adherence
• Isolate entire muscle by direct visualization
• Keep new insertion behind the inferior rectus
  insertion with posterior muscle fibers posterior
  AVOID the J