EXOTROPIA

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EXOTROPIA
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EXOTROPIA
DR. LIONEL KOWAL FRANZCO, FRACS MELBOURNE,
AUSTRALIA
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EXOTROPIA
ETIOLOGY OF EXODEVIATIONS NOT A MIRROR IMAGE OF
ESOTROPIA
BALANCE OF FASCIAL FORCES IN ORBIT HARD TO
QUANTIFY ANESTHESIA POORLY
UNDERSTOOD ANATOMICAL FACTORS ORBITAL SHAPE LR
TENSION MAY BE NORMAL ET MR ALWAYS HIGH
ROSENBAUM LESS RELIABLE SURGICAL RESULTS
Kowal
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EXOTROPIA
ETIOLOGY OF EXODEVIATIONS

• NEED TO EXPLAIN ALL OF
• CAUCASIAN ET gt XT
• ASIA XT gt ET
• JAPAN CONV INSUFF COMMONEST XT
• POSSIBLE REASONS / ASSOCIATIONS
• gt 25 CAUCASIAN NEONATES gt 4
• gt 60 ADULT ASIANS MYOPIC
• ORBITAL SHAPE IN ASIANS

Kowal
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EXOTROPIA
ETIOLOGY OF EXODEVIATIONS MOTOR FUSION ?
PROTECTS AGAINST XT
REDUCED MF ? MORE PRONE TO XT S ?VA ANY
REASON e.g. AMBLYOPIA M CYCLOVERTICAL
ANOMALY MF gt EXO PHORIA MF EXO I/MITT
TROPIA MF lt EXO CONSTANT TROPIA
Kowal
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EXOTROPIA
STANDARD XT D gt N WHY? MF NgtD -
PROVIDES MORE PROTECTION AGAINST NEAR XT
OTHER PROXIMAL MECHANISMS ARE ADDITIVE
(TPF)
Kowal
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EXOTROPIA
KUSHNER ARCHIVES 2-4/98, 2/99
NEW MINIMUM STANDARDS FOR EVALUATION OF
XT TARGET ANGLE SURGICAL DOSE DEPENDENT ON
SEVERAL SUBTLE ASPECTS OF EXAMINATION
Kowal
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EXOTROPIA
KUSHNER SCHEME 1

• 20 ft EXAM
• OUTSIDE TARGET EXAM
• PATCH FOR 1 HOUR
• B,C ½ PTS - XT ANGLE AUGMENTS
• ? LARGER SURGICAL DOSE

Kowal
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EXOTROPIA
KUSHNER SCHEME 2
? DIVERGENCE XS (DX) C PATCH 1 HOUR 80 of DX
BECOME D N ?Simulated DX DX PERSISTS CHECK
WITH 3 FOR N TRUE HIGH ACA / TRUE DX
Kowal
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EXOTROPIA
OTHER EXOTROPIAS

• DXD
• CONSECUTIVE XT
• 3. INFANTILE XT
• 4. CONVERGENCE INSUFFICIENCY
• 5. NEUROLOGICAL XT

Kowal
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EXOTROPIA
DXD RAAB, WILSON

• DISSOCIATED EXO DEVIATION
• LOOKS LIKE UNILATERAL XT
• E.G. RIGHT FIXATION L EXO
• LEFT FIXATION NO EXO
• Exclude Uncorrected LE RMR UA
• COUSIN OF D.V.D
• ?SIMILAR NYSTAG BLOCKING MECHANISMS
• ALL Smooth Pursuit Asymm / CONGENITAL STRAB
• MANY PREVIOUS LR RESECT

Kowal
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EXOTROPIA
CONSECUTIVE XT
CIANCIA 390 CASES CONG ET WEEK 1 90
ORTHO 10-28y follow up 20 gt 10? XT
THAT AMOUNT OF MR RECESS ? SUCCESSFUL EARLY
ALIGNMENT EVENTUALLY ? CONSEC XT IN 20
Kowal
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EXOTROPIA
CONSECUTIVE XT
1.MOTOR FACTORS SCAR REMODELLING / MIGRATION
LUDWIG ALPHABET PATTERNS esp. A SUBSEQUENT
GLOBE / ORBITAL GROWTH 2. SENSORY FACTORS MORE
COMMON WITH HIGH POOR PERIPHERAL FUSION
Kowal
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EXOTROPIA
INFANTILE XT

• MIRROR IMAGE CONG ET
• EARLY ONSET REGULAR XT
• SYSTEMIC DISEASE esp. CNS

Kowal
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EXOTROPIA
CONVERGENCE INSUFFICENCY
MULTIPLE DIAGNOSTIC CRITERIA REMOTE NPC
X XT N gt D REDUCED NEAR
BOFR MULTIPLE CLINICAL TYPES CHILDHOOD
ADOLESCENT SENILE
NEUROLOGICAL AWAITS RECLASSIFICATION AND
IMPROVED UNDERSTANDING
Kowal
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EXOTROPIA

• BREAKDOWN OF PRE-EXISTING PHORIA
• DANGEROUS DIAGNOSIS
• I.N.O.
• FIELD DEFECT all types
• POOR MOTOR FUSION TBI, PARKINSONS
• VE NEURONAL ANTIBODY
• C.P.E.O.
• MYESTHENIA

NEUROLOGICAL XT
Kowal
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EXOTROPIA
CORE SLIDE DECIDING ON THRESHOLD FOR TREATMENT

• DELICATE / CAREFUL BALANCE BETWEEN
• NATURAL HISTORY
• ADVANTAGES OF XT
• DISABILITY OF XT DISABILITY SCORE
• ADVANTAGES OF RX
• MORBIDITY OF RX

Kowal
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EXOTROPIA
SYMPTOMS SCORE
UCLA HOME

• XT, EXO
• MANIFEST TIRED , INATTENTIVE
• XT lt 5/d
• XT gt 5/d
• EXO
• 4. ONLY OCCASIONALLY STRAIGHT

Kowal
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EXOTROPIA
SYMPTOMS SCORE
UCLA OFFICE

• COVER TEST TO BREAK?RAPID RECOVERY
• RECOVERY AFTER BLINKING
• BREAKS SPONTANEOUSLY

Kowal
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EXOTROPIA
MELBOURNE XT SYMPTOM SCORE

• POTS OF TIME STRABISMIC
• ______x 10
  /10
• 2. M.E.C.
  /3
• DIPLOPIA
  /2
• OTHERS NOTICE IT /2
• OTHER _____________ /2
• 
  _____
• 
  /17
• USUAL THRESHOLD
  7-8
• 
  

Kowal
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EXOTROPIA
OTHER FACTORS TO REACH THRESHOLD

• GLARE SENSITIVITY
• ? DISTANCE STEREO
• BOTHERSOME AWARENESS
• OF XT ADULTS
• BINOCULAR BLUR

Kowal
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EXOTROPIA
OTHER FACTORS TO REACH THRESHOLD
BINOCULAR BLUR La Roche 12y old I/MITT
BLUR 2y ago I/MITT M.E.C. DIPLOPIA 5y ago
I/MITT MISALIGNMENT BEO 20/25 EITHER
EYE 20/20 NOW SYMPTOMS OF Xs ACCOMMODATION 2y
ago SYMPTOMS OF EXO
Kowal
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EXOTROPIA
CONCLUSION

• XT COMPLEX
• MORE TRAPS
• MORE DIFFICULT TO EVALUATE
• THRESHOLD FOR RX
• DEPENDENT ON SYMPTOMS

Kowal
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EXOTROPIA
VERTICALS IN XT
E.G. XT 30, LH 6 EX0 8
CYCLOVERTICAL MUSCLES Vertical Fusion Range
lt3? ? FRAGILE BALANCE c.f. HORIZ FR WITH
LITTLE / NO ROOM FOR ERROR 15 HORIZONTAL
MISALIGNMENT VERTICAL IMBALANCE NO SURPRISE
Kowal
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EXOTROPIA
THRESHOLD FOR TREATMENT
SYMPTOMS DEFINE THE NEED TO RX SIGNS DEFINE HOW
TO RX
Kowal