Sensory causes of diplopia - profound Abnormal Retinal

Corrspondence ARC

LIONEL KOWAL

MELBOURNE

Financial disclosure:

There’s no $ in ARC - stick to cataracts

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

Results n=9

• 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

Typical pt - having first XT surgery in her 40’s

All measurements are ET. Diplopia is all uncrossed

SH - 1st ET surgery in her 20’s

• LET 20∆, amblyopia 6/30 since childhood.

• Early recurrence of ET after Rs+Rc

• 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

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

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