EXOTROPIA. DR. LIONEL KOWAL FRANZCO, FRACS MELBOURNE, AUSTRALIA.
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Transcript of EXOTROPIA. DR. LIONEL KOWAL FRANZCO, FRACS MELBOURNE, AUSTRALIA.
EXOTROPIA
EXOTROPIA
DR. LIONEL KOWAL FRANZCO, FRACS
MELBOURNE, AUSTRALIA
EXOTROPIA
Kowal
ETIOLOGY OF EXODEVIATIONS
NOT A MIRROR IMAGE OF ESOTROPIA
BALANCE OF FASCIAL FORCES IN ORBITHARD TO QUANTIFY ANESTHESIA
POORLY UNDERSTOOD ANATOMICAL FACTORSORBITAL SHAPE
LR TENSION MAY BE NORMALET: MR ALWAYS HIGH [ROSENBAUM]
LESS RELIABLE SURGICAL RESULTS
EXOTROPIA
Kowal
ETIOLOGY OF EXODEVIATIONS
NEED TO EXPLAIN ALL OF:CAUCASIAN : ET > XTASIA : XT > ETJAPAN : CONV INSUFF COMMONEST XT
POSSIBLE REASONS / ASSOCIATIONS> 25% CAUCASIAN NEONATES > +4> 60% ADULT ASIANS MYOPICORBITAL SHAPE IN ASIANS
EXOTROPIA
Kowal
ETIOLOGY OF EXODEVIATIONS
MOTOR FUSION ’PROTECTS’ AGAINST XT
REDUCED MF → MORE PRONE TO XTS: VA ANY REASON e.g. AMBLYOPIAM: CYCLOVERTICAL ANOMALY
MF > EXO : PHORIAMF = EXO: I/MITT TROPIAMF < EXO: CONSTANT TROPIA
EXOTROPIA
Kowal
‘STANDARD’ XT : D > N – WHY?
MF : N>D - PROVIDES MORE ‘PROTECTION’ AGAINST NEAR XT
&OTHER PROXIMAL MECHANISMS
ARE ADDITIVE (TPF)
EXOTROPIA
Kowal
KUSHNER ARCHIVES 2-4/98, 2/99
NEW MINIMUM STANDARDS FOR EVALUATION OF XT
TARGET ANGLE & SURGICAL DOSEDEPENDENT ON SEVERAL SUBTLE ASPECTS OF EXAMINATION
EXOTROPIA
Kowal
KUSHNER SCHEME 1
A. 20 ft EXAM &B. OUTSIDE TARGET EXAM &C. PATCH FOR 1 HOUR
B,C : ½ PTS - XT ANGLE AUGMENTS LARGER SURGICAL DOSE
EXOTROPIA
Kowal
KUSHNER SCHEME 2
? DIVERGENCE XS (DX)C : PATCH 1 HOUR80% of DX BECOME D = N →Simulated DX
DX PERSISTS:CHECK WITH +3 FOR N TRUE HIGH ACA / TRUE DX
EXOTROPIA
Kowal
OTHER EXOTROPIAS
1. DXD2. CONSECUTIVE XT3. INFANTILE XT4. CONVERGENCE INSUFFICIENCY5. NEUROLOGICAL XT
EXOTROPIA
Kowal
DXD [RAAB, WILSON]
DISSOCIATED EXO DEVIATIONLOOKS LIKE ‘UNILATERAL’ XT
E.G.: RIGHT FIXATION : L EXOLEFT FIXATION : NO EXOExclude: Uncorrected + LE & RMR UA
“COUSIN” OF D.V.D?SIMILAR NYSTAG BLOCKING MECHANISMS
•ALL : Smooth Pursuit Asymm / CONGENITAL STRAB•MANY : PREVIOUS LR RESECT
EXOTROPIA
Kowal
CONSECUTIVE XT
CIANCIA : 390 CASES CONG ETWEEK 1 : 90% ORTHO10-28y follow up : 20% > 10∆ XT
** THAT AMOUNT OF MR RECESS → SUCCESSFUL EARLY ALIGNMENT
EVENTUALLY → CONSEC XT IN 20%
EXOTROPIA
Kowal
CONSECUTIVE XT1.MOTOR FACTORS
SCAR REMODELLING / MIGRATION [LUDWIG]
ALPHABET PATTERNS esp. ASUBSEQUENT GLOBE / ORBITAL GROWTH
2. SENSORY FACTORS
MORE COMMON WITH HIGH + POOR PERIPHERAL FUSION
EXOTROPIA
Kowal
INFANTILE XT
•MIRROR IMAGE CONG ET
•EARLY ONSET “REGULAR” XT
•SYSTEMIC DISEASE esp. CNS
EXOTROPIA
Kowal
CONVERGENCE INSUFFICENCY
MULTIPLE DIAGNOSTIC CRITERIAREMOTE NPC X’XT N > D REDUCED NEAR BOFR
MULTIPLE CLINICAL TYPESCHILDHOOD ADOLESCENTSENILE NEUROLOGICAL
AWAITS RECLASSIFICATION AND IMPROVED UNDERSTANDING
EXOTROPIA
Kowal
NEUROLOGICAL XT
‘BREAKDOWN OF PRE-EXISTING PHORIA’DANGEROUS DIAGNOSIS
•I.N.O.•FIELD DEFECT all types
•POOR MOTOR FUSION TBI, PARKINSON’S
•+VE NEURONAL ANTIBODY •C.P.E.O.
•MYESTHENIA
EXOTROPIA
Kowal
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
EXOTROPIA
Kowal
SYMPTOMS SCORE
UCLA : HOME
1. XT, EX’=OMANIFEST TIRED , INATTENTIVE2. XT < 5/d3. XT > 5/d EX’=O4. ONLY OCCASIONALLY STRAIGHT
EXOTROPIA
Kowal
SYMPTOMS SCORE
UCLA : OFFICE
1. COVER TEST TO BREAK→RAPID RECOVERY
2. RECOVERY AFTER BLINKING
3. BREAKS SPONTANEOUSLY
EXOTROPIA
Kowal
MELBOURNE XT SYMPTOM SCORE
1. POTS % OF TIME STRABISMIC ______x 10% = /102. M.E.C. /33. DIPLOPIA /24. OTHERS NOTICE IT /25. OTHER _____________ /2 _____ /17+USUAL THRESHOLD 7-8
EXOTROPIA
Kowal
OTHER FACTORS TO REACH THRESHOLD
•GLARE SENSITIVITY
•↓ DISTANCE STEREO
•BOTHERSOME AWARENESS OF XT [ADULTS]
•BINOCULAR BLUR
EXOTROPIA
Kowal
OTHER FACTORS TO REACH THRESHOLD
BINOCULAR BLUR [La Roche]
12y old : I/MITT BLUR2y ago : I/MITT M.E.C. & DIPLOPIA5y ago : I/MITT MISALIGNMENT BEO : 20/25 EITHER EYE : 20/20
NOW SYMPTOMS OF Xs ACCOMMODATION2y ago : SYMPTOMS OF EXO
EXOTROPIA
Kowal
CONCLUSION•XT COMPLEX
•MORE TRAPS
•MORE DIFFICULT TO EVALUATE
•THRESHOLD FOR RX : DEPENDENT ON SYMPTOMS
EXOTROPIA
Kowal
VERTICALS IN XT
E.G. XT 30, LH 6 EX’=0
8 CYCLOVERTICAL MUSCLES Vertical Fusion Range ± <3∆
→ FRAGILE BALANCE c.f. HORIZ FR WITH LITTLE / NO ROOM FOR ERROR
15° HORIZONTAL MISALIGNMENT : VERTICAL IMBALANCE NO SURPRISE
EXOTROPIA
Kowal
THRESHOLD FOR TREATMENT
SYMPTOMS DEFINE THE NEED TO RX
SIGNS DEFINE HOW TO RX