Sensory causes of diplopia - profound Abnormal Retinal Corrspondence ARC

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Sensory causes of diplopia - profound Abnormal
Retinal Corrspondence ARC

• LIONEL KOWAL
• MELBOURNE
• Financial disclosure
• Theres no in ARC - stick to cataracts

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Introduction

• ARC suppression in strabismus are common
  prevent symptomatic diplopia in the presence of
  frank tropia.
• ARC prevents confusion about straight-
  aheadedness and can allow some binocularity
  despite strabismus.
• When strabismic eyes are straightened, ARC
  usually resolves quickly.
• Unresolved ARC will cause (paradoxical) diplopia
  despite straight eyes .
• If the ARC is profound the diplopia may persist.
• Profound ARC can often be predicted
  pre-operatively

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Results n9

• Retrospective chart study. Ages 18 - 62.
• 6 were XT.
• All definite or probable childhood-onset strab
• 2 first surgery under age 5
• 7 first surgery 16 or older 16,20, 24, 25,
  38,43,62
• Risk of paradoxical diplopia due to profound ARC
  was appreciated pre-operatively in 3
• 1/3 postop suppression, no postop diplopia

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Typical pt - having first XT surgery in her 40s
All measurements are ET. Diplopia is all uncrossed
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SH - 1st ET surgery in her 20s

• LET 20?, amblyopia 6/30 since childhood.
• Early recurrence of ET after RsRc
• After 2nd surgery, straight with new visual
  field in the temporal field of LE
• Xed Diplopia on her L in her new field - ARC
  only in her new field
• Diplopia resolved in 2 mo

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Results

• Symptoms disappeared in 2-8 weeks
• ARC for near disappeared before distance
• Using Fresnel ? for diplopia did not hinder
  resolution of symptoms
• 1 diplopia persisting after 8 months
• 1 paradoxical ARC with the pseudofovea of
  infantile esotropia acting in exotropia

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Conclusion

• Most BUT NOT ALL patients with postop paradoxical
  diplopia due to ARC resolve after surgical
  alignment.
• Deferring alignment surgery to adulthood is a
  risk factor in this cohort