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EXOTROPIA. EXOTROPIA. DR. LIONEL KOWAL FRANZCO, FRACS MELBOURNE, AUSTRALIA. 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
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EXOTROPIA DR. LIONEL KOWAL FRANZCO, FRACS MELBOURNE, AUSTRALIA
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
EXOTROPIA ETIOLOGY OF EXODEVIATIONS NEED TO EXPLAIN ALL OF: CAUCASIAN : ET > XT ASIA : XT > ET JAPAN : CONV INSUFF COMMONEST XT POSSIBLE REASONS / ASSOCIATIONS > 25% CAUCASIAN NEONATES > +4 > 60% ADULT ASIANS MYOPIC ORBITAL SHAPE IN ASIANS Kowal
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 > EXO : PHORIA MF = EXO: I/MITT TROPIA MF < EXO: CONSTANT TROPIA Kowal
EXOTROPIA ‘STANDARD’ XT : D > N – WHY? MF : N>D - PROVIDES MORE ‘PROTECTION’ AGAINST NEAR XT & OTHER PROXIMAL MECHANISMS ARE ADDITIVE(TPF) Kowal
EXOTROPIA KUSHNERARCHIVES 2-4/98, 2/99 NEW MINIMUM STANDARDS FOR EVALUATION OF XT TARGET ANGLE & SURGICAL DOSE DEPENDENT ON SEVERAL SUBTLE ASPECTS OF EXAMINATION Kowal
EXOTROPIA KUSHNER SCHEME1 • 20 ft EXAM & • OUTSIDE TARGET EXAM & • PATCH FOR 1 HOUR • B,C : ½ PTS - XT ANGLE AUGMENTS • LARGER SURGICAL DOSE Kowal
EXOTROPIA KUSHNER SCHEME2 ? 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
EXOTROPIA OTHER EXOTROPIAS • DXD • CONSECUTIVE XT • 3. INFANTILE XT • 4. CONVERGENCE INSUFFICIENCY • 5. NEUROLOGICAL XT Kowal
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
EXOTROPIA CONSECUTIVE XT CIANCIA : 390 CASES CONG ET WEEK 1 : 90% ORTHO 10-28y follow up : 20% > 10∆ XT ** THAT AMOUNT OF MR RECESS → SUCCESSFUL EARLY ALIGNMENT EVENTUALLY → CONSEC XT IN 20% Kowal
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
EXOTROPIA INFANTILE XT • MIRROR IMAGE CONG ET • EARLY ONSET “REGULAR” XT • SYSTEMIC DISEASE esp. CNS Kowal
EXOTROPIA CONVERGENCE INSUFFICENCY MULTIPLE DIAGNOSTIC CRITERIA REMOTE NPC X’ XT N > D REDUCED NEAR BOFR MULTIPLE CLINICAL TYPES CHILDHOOD ADOLESCENT SENILE NEUROLOGICAL AWAITS RECLASSIFICATION AND IMPROVED UNDERSTANDING Kowal
EXOTROPIA • ‘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 NEUROLOGICAL XT Kowal
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
EXOTROPIA SYMPTOMS SCORE UCLA : HOME • XT, EX’=O • MANIFEST TIRED , INATTENTIVE • XT < 5/d • XT > 5/d • EX’=O • 4. ONLY OCCASIONALLY STRAIGHT Kowal
EXOTROPIA SYMPTOMS SCORE UCLA : OFFICE • COVER TEST TO BREAK→RAPID RECOVERY • RECOVERY AFTER BLINKING • BREAKS SPONTANEOUSLY Kowal
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
EXOTROPIA OTHER FACTORS TO REACH THRESHOLD • GLARE SENSITIVITY • ↓ DISTANCE STEREO • BOTHERSOME AWARENESS • OF XT [ADULTS] • BINOCULAR BLUR Kowal
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
EXOTROPIA CONCLUSION • XT COMPLEX • MORE TRAPS • MORE DIFFICULT TO EVALUATE • THRESHOLD FOR RX : • DEPENDENT ON SYMPTOMS Kowal
EXOTROPIA 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 Kowal
EXOTROPIA THRESHOLD FOR TREATMENT SYMPTOMS DEFINE THE NEED TO RX SIGNS DEFINE HOW TO RX Kowal