STRABISMUS
REOPERATION :
A SECOND CHANCE
PRE-OPERATIVE
EVALUATION
LIONEL KOWAL
MELBOURNE AUSTRALIA
STRABISMUS REOPERATION :
A SECOND CHANCE
Starting points:
This will be difficult
I need to be careful and accurate in
my evaluation
My pt’s expectations may be
unrealistically high
STRABISMUS REOPERATION :
A SECOND CHANCE
PRE-OPERATIVE EVALUATION
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How did the pt get to this point?
Full exam
Surgical plan
Patient’s expectations = Dr’s
THE NEED FOR RE-OPERATION
IS IT ANYONE’S FAULT?
CONG ET
NEED FOR RE-OPERATION CAN BE PART
OF THE NATURAL HISTORY OF
ALIGNMENT SURGERY
PART OF THE NATURAL HISTORY
OF ALIGNMENT SURGERY
CIANCIA’S EXTRAORDINARY PERSONAL
SERIES OF CONG ET
 BMR
SOME: OTHER MUSCLES ALSO
 WEEK 1: 90% ORTHOTROPIA
 5Y: 10% CONSEC XT
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15+Y:
30% CONSEC XT
Follow up about 50%
NATURAL HISTORY OF SUCCESSFUL
ALIGNMENT SURGERY IN CONG ET
THAT AMOUNT OF MEDIAL RECTUS
REPOSITIONING REQUIRED FOR
ALIGNMENT IN CONG ET WILL, WITH
SUBSEQUENT GROWTH OF EYE,
MUSCLE, ORBIT
→ REDUCED MR FUNCTION IN 30%
→ XT NEEDING TREATMENT
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NATURAL HISTORY OF SUCCESSFUL
ALIGNMENT SURGERY IN CONG ET
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SUCCESSFUL HORIZONTAL
STRAIGHTENING DOES NOT PRECLUDE
SUBSEQUENT DEVPT OF DVD
REQUIRING Rx
THE NEED FOR RE-OPERATION
IS IT ANYONE’S FAULT? EXOTROPIAS
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ET : MR ALWAYS TIGHT & MR Rc
ADDRESSES THE BASIC PROBLEM.
XT DUE TO ‘ABNORMAL BALANCE OF
FASCIAL FORCES WITHIN THE ORBITS’
XT : LR NOT ALWAYS TIGHT.
LR SURGERY DOESN’T ALWAYS
ADDRESS THE BASIC PROBLEM IN XT
→ HIGHER LONG TERM FAILURE RATE
THAN ET
THE NEED FOR RE-OPERATION
IS IT ANYONE’S FAULT?
SURGERY MECHANICALLY REALIGNS THE EYES
EYES THEN HELD STRAIGHT BY:
 STABLE MUSCLE- SCLERA UNION
LUDWIG: NOT ALWAYS SO
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NORMAL MUSCLE MECHANICS
5mm recess may function better than 7mm recess
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FUSIONAL VERGENCE – KEEPS ANY
MISALIGNMENT AS A PHORIA
SENSORY FACTORS IN
MAINTAINING STRAIGHTNESS
GOOD SENSORY FUSION NEEDED FOR
GOOD MOTOR FUSION
 HIGH AMETROPIA esp high+ →
POOR PERIPHERAL FUSION →
SPONT / CONSEC XT MORE COMMON
 POOR VISION →
POOR PERIPH & POOR CENTRAL FUSION →
SPONT XT MORE COMMON
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PRE OPERATIVE
EVALUATION:HISTORY
REOPERATION FOR DIPLOPIA
ACCURATE HISTORY : HOW TROUBLESOME
IS IT?
Diplopia itself
Sore neck?
COMMONLY MISSED BARRIERS TO FUSION:
** TORSION
** ANISEIKONIA
PREDISPOSITION TO DIPLOPIA
REALIGNMENT IN PT WITHOUT DIPLOPIA:
TESTS WITH probably GOOD Pos Pred Value
FOR POST OP SINGLE VISION
1. CAN THE PT RECALL SINGLE VISION
WHEN PERFECTLY ALIGNED?
2. PRISM & PAT
3. Botox testing [UK]
PRE OPERATIVE EVALUAION:HISTORY
TIME COURSE OF STRAB
Recurrence / overcorrection seen early
has different etiology / Rx /
expectations to that seen late
Accurate history supported by Family
Album Test important
PRE OPERATIVE EVALUAION:HISTORY
TIME COURSE OF STRAB
CASE 32 YO [XT], WORSE IF TIRED.
ET & THICK GLS WHEN YOUNG
RECALLS PARENTS’ / DOCTORS’
CONCERN ABOUT ADDUCTION IN
Week 1 AFTER BMR age 7.
NOW : LMR UA > RMR UA
Manifest Refraction + 2 DS OU.
Uncorrected vision 20/20.
PRE OPERATIVE EVALUATION HISTORY
STRETCHED SCAR OF LUDWIG
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POOR SCAR MATURATION /
ILLNESS / MALNUTRITION
INTERFERES WITH INTEGRITY OF
MUSCLE/ SCLERA UNION →
STRETCHED SCAR
LOOKS LIKE MUSCLE HAS SLIPPED
WITHIN ITS TENDON
POTENTIALLY HAZARDOUS
DURING SURGERY [‘SNAP!’]
PRE OPERATIVE EVALUATION HISTORY
STRETCHED SCAR OF LUDWIG
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ONE CAUSE OF CONSEC XT AFTER BMR
EXAMINE EASILY VISIBLE SURGICAL
SCARS ON SKIN - ?THIN ATROPHIC
SCARS MAY REFLECT MUSCLE /
SCLERA UNION ? XS STRETCHMARKS
NON-ABSORBABLE SUTURES FOR REOP
PRE OPERATIVE EVALUATION:
THE PLAN
40 yo WCF consec XT
No baby photos – looked too bad
4 surgeries ages 2,8,12,13
variously ET /XT
Never had diplopia
‘perfectly’ aligned ages 13-29
1st pregnancy @ 29: XT develops
PRE OPERATIVE EVALUATION:
THE PLAN
40 yo WCF
consec XT
BCVA +3 etc 20/30+, +4 etc 20/40
XT 30Δ, XT’ 40Δ
Smooth pursuit asymmetry
RMR UA > LMR UA
Scars all H recti
PRE OPERATIVE EVALUATION:
THE PLAN
40 yo WCF
consec XT
EXPECTATIONS
? Over Rc MR OU
? Stretched scar
SURGICAL PLAN
Explore MR OU with great care
Make MR function normal
Early ET desirable = best result
2nd best result : larger early ET
PRE OPERATIVE EVALUATION:
THE EXAMINATION
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DO AN ACCURATE / COMPLETE STRAB
EXAM
CHECK GLS FOR Δ & PALs
NEUTRALISE STRAB WITH Δ & CHECK
SENSORY RESPONSE
PRE OPERATIVE EVALUATION:
THE EXAMINATION : FACTORS THAT MAY
MODIFY THE SURGICAL PLAN
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IF LATERAL / VERTICAL
INCOMITANCES LOOK FOR ALL THE
USUAL ASSOCIATED FACTORS TO
MAKE SURE IT ALL ‘FITS’
PRE OPERATIVE EVALUATION:
THE EXAMINATION : FACTORS THAT MAY
MODIFY THE SURGICAL PLAN
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VERSION / DUCTION DEFICITS /
OVERACTIONS
IS A DEFICIT DUE TO UA OR RESTRICTION?
MR UA looks like tight LR
FORCEPS TESTING – IS DUCTION DEFICIT
DUE TO WEAKNESS OR RESTRICTION?
Rc LR when the MR is weak → result won’t
last
PRE OPERATIVE EVALUATION:
SPECIAL AND FANCY TESTS
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RISK OF ISCHAEMIA
NEED TO OPERATE ON ADJACENT MUSCLES
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NORMAL IRIS ANGIOGRAM
ENCOURAGING
PRE OPERATIVE EVALUATION:
SPECIAL AND FANCY TESTS
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WHEN TO SCAN
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EVOLVING
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IF THINGS DON’T ‘FIT’
PRE OPERATIVE EVALUATION
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Reops are difficult for patient and Dr
Careful complete assessment
Careful pt education
2nd opinions sensible for difficult cases
Starting with humility is easier than
having it thrust on you