Different types of Inferior Oblique Surgery - The Private Eye Clinic

12/14/2007• Duane – tenotomy/myectomy at originInferior oblique muscleoperationsDr Elina LandaFellowOcular Motility Clinic, RVEEH,Melbourne• Dunnington – IO weakening at its insertion• White – IO recession• 1980-19901990 Gobin, A Scott, Apt, Call - IOATSurgical optionsM. ParksGoal- to weaken or to change function• Myotomy Advantage - simpleDisadvantage – high recurrence rate• Myectomy Advantage – swiftnessDisadvantage - recurrence• Disinsertion Advantage – simpleDisadvantage- recurrence; better when combined withmyectomy• Recession Advantage – lower recurrence rate; good for reoperationsDisadvantage – more time consuming; more complicated forperformance• Denervation Advantage – for extremely overacted IODisadvantage – difficult; postop mydriasis 3-6 m; IOUAfor 3-6 mM. ParksIO weakening procedures• 370 pts with bilateral IOOA• 4 groups1gr 150pts with bilateral recession2gr 100pts – LE recess; RE disinsertion3gr 20pts – LE recess; RE nasal myectomy4gr 100pts – LE recess; RE myectomyResultsUnderactionOveractionMyectomyat insertion8%30%Disinsertion3%53%Myectomyat origin0%79%Recession4%15%Results• IO is superior to other surgeries+2 +3 IOOA- 83% perfect result+4 IOOA- 78% perfect; 21%undercorrection• Recession should be titrated• Identical recess on eyes with asymmetricalIOOA produces symmetrical results1

12/14/2007Parks’ recessionIO anterior transpositionIRAVortex veinLRBcA – 8-10mm recessB- 14mm recessC- 6mm recess•Suturing IO with 1suture augmentsrecession and decreasetorsion•Neurovascular bundleacts as an origin andfunctional tetherIOAT• Park’s recession 8-10mm (c)Bilateral IOAT by Mims and Wood• Alan Scott IOAT (B)• Mims and Wood IOAT (A)OIRCBAI61 children after IOAT• 1 recurrent IOOA• 1 need for DVD surgery60 children withoutIOAT• 9 need for DVD surgery•Conclusion:- IOAT is effective for IOOA with lowincidence of need for reoperationprevention of DVD- IOAT is effective in reduction orA.Ziffer, S. Isenberg…The comparison of bilateral IOATand recession36 pts- bilateral IOAT• IO function -25*(n-35-4040*)• 14 pts- bilateral IOrecession• 10mm- IO function is31*• 14mm- IO function is38*•IOAT- significant weakening effect for IO- reduces upgaze•10mm recess more powerful than 14mm recessionR Muchnick, D.McCullough…Unilateral IOAT vs unilateral 14mmIO recession5 pts – IOAT• Mean reduction of HTin PP – 12 pd• Mean deviation in thefield of IO – 2 pdhypo (change 23 pd)• 4 units reduction inductions (+2.5 to -1.5)•Both procedures are effective•Both did not show overcorrection in PP4 pts- 14mm recess• Mean reduction of HTin PP – 11 pd• Mean deviation in thefield of IO – 3 pdhyper (change 22pd)• 3 units reduction inductions ( +3 to+0.5)2

12/14/2007Carlos Souza- DiasUnilateral IOAT• 10 pts with idiopathic unilateral IOOA;HT> than 10pd in PP; IOOA >/= +3• Results no hypo in PP4 pts – overcorrection without diplopia9/10 – residual HT < 6 pd; one- 8pdMean correction – 20pd for PP HTSantiago, IsenbergIOAT effect on torsion• 24 eyes of 13 pts• Fundus photos 1 week before and 6 w after thesurgery• Results 6 w postop -29% reduction of torsion10 w postop – 13% reduction of original torsion33% reduction if IOAT near or anterior to IR insertion8% reduction if IOAT posterior to IR insertionResidual fundus extorsion – recurrent IOOAStagerAnterior and nasal IOTStagerAnterior and nasal IOT• 20 pts with severe IOOA ( +4; absent SO; failed IOweakening)10 pts – unilateral ANT10pts- bilateral ANT9 pts – a secondary procedureResults : 10 pts with SOP5 pts cong SOP 5 pts acquired( post RD,Harada-Ito, tumor)FIG 1. A, Schematic representation (inferior view) of thetraditional anterior transposition of the IO muscle. B, Placingthe new IO muscleinsertion close to the temporal border of the IR muscledecreases the risk of AES.9 C, Placing the new insertion evenfurther nasally shoulddecrease the risk of AES even more.13 The axes x, y, and zare the axes of Fick and correspond to the directions ofrotation of the globe.4 pts only ANT 1 after IOweak 1 with absent SOAll had improvement2 pts limitation of elevationStagerAnterior and nasal IOT4 pts with primary IOOA(3 had previous IO recess) improvedextorsion and IO function. All showed limitation of elevation2 pts with AES after IOAT – improvement2 pts with Duane: 1 eliminated increase in adduction1 no effect ( abnormal LR pulleys)1 pt with Y pattern – no effect ( abnormal IRResults of ANT decrease in elevation in adductiondecreased extorsiontonic depressionimprovement of head posture in severe SOPimprovement of V-patternStagerAnterior and nasal IOT• Limitations of ANTlimits elevationmay induce intorsioncould make downshoot worse in Duanemay not be successful after multiple surgeriesRecommended for severe or recurrent IOOA when othertechniques have failed4

12/14/2007StagerANT in pts with missing SO tendon• 9 pts were included2- unilateral7- bilateralResultsunilateral-Ortho in all gazes-1 - 5* tilt-1 – mild overcorrectionbilateral-6 – no IOOA-1 – no effect in both eyes-1 – overcorrection-2eyes– SO underactionappeared worse-22 pts had additionaloperationsOther surgical procedures• Gonzales, Klein 4mm distal myectomy + IOAT forprimary IOOA and IOOA+DVD :86% - n IO function85%- improvement of DVD• Stager, Weakly 5mm proximal (nasal) myectomy+IOAT of the distal part for recurrent IOOA, DVD:IOOA was eliminated in all casesDVD reduced in 4/17; unchanged10/17; increased in 3/17How should we proceed?5