This document discusses factors affecting outcomes in resurgery for strabismus. Key factors include careful preoperative measurements, findings at initial surgery, risk of overcorrection based on patient characteristics, and unmasking of other ocular issues. The success rate for resurgery of congenital esotropia is 80-85%. Planning for resurgery involves reviewing previous records to identify virgin versus re-operated muscles. Expectations are for stable alignment, full eye movement, and good cosmesis. Resurgery is typically performed at least 2 months after initial surgery, except for specific cases. Reoperation is expected in 5-10% of strabismus surgeries and each reoperation increases the risk

1. Factors affecting surgicalFactors affecting surgical
outcome in Resurgery –outcome in Resurgery –
How to proceedHow to proceed
Dr. Madhu KarnaDr. Madhu Karna
Consultant Pediatric OphthalmologistConsultant Pediatric Ophthalmologist

2. Cooper’s dictum – as though new cases withCooper’s dictum – as though new cases with
appropriate orthoptic, medical and surgicalappropriate orthoptic, medical and surgical
remediesremedies
 Careful measurements and ocular rotationsCareful measurements and ocular rotations
 Force and velocity studiesForce and velocity studies
 Findings at surgeryFindings at surgery
Risk factors for overcorrection- A pattern,Risk factors for overcorrection- A pattern,
amblyopia, high hyperopiaamblyopia, high hyperopia

3.  Non seeing eyeNon seeing eye
 Seeing pts-Seeing pts-
 first surgery resultfirst surgery result
 Progressive problemProgressive problem
 Unmasking of other components - ReoperationsUnmasking of other components - Reoperations
inevitableinevitable
Congenital esotropia without nystagmus- 80-85%Congenital esotropia without nystagmus- 80-85%
success ratesuccess rate

4. Operated infantile esotropiaOperated infantile esotropia
presenting with DVDpresenting with DVD

5. PostopPostop

6. When to reoperateWhen to reoperate
At least 2 months after the initial surgery except:At least 2 months after the initial surgery except:
 Lost or slipped muscleLost or slipped muscle
 Large overcorrection after an SO tuckLarge overcorrection after an SO tuck
 Large vertical deviations induced by muscleLarge vertical deviations induced by muscle
transposition procedurestransposition procedures

7. ExpectationsExpectations
 Stable alignmentStable alignment
 Full ocular rotationFull ocular rotation
 Good cosmesis – white /noninflamed eye ,Good cosmesis – white /noninflamed eye ,
symmetric lid fissuressymmetric lid fissures

9. PlanningPlanning
 Lookup the records – helps to decide virginLookup the records – helps to decide virgin
muscle or redo operated musclesmuscle or redo operated muscles
 Look for the scar at the insertion.Look for the scar at the insertion.
 Plica drawn up into medial bulbar scarPlica drawn up into medial bulbar scar
 12-15 LRrec,11-12 MRrec causes -1.5 limitation12-15 LRrec,11-12 MRrec causes -1.5 limitation
of abd and addof abd and add

10. HurdlesHurdles
 Conjunctiva – String or indentation signConjunctiva – String or indentation sign
 Muscle – Excessive resectionsMuscle – Excessive resections
 Scar – Following intraconal fat violationScar – Following intraconal fat violation
Leash – restrict rotation the opposite fieldLeash – restrict rotation the opposite field
Reverse leash – limit rotations in the same fieldReverse leash – limit rotations in the same field
Uncooperative patient – do under GAUncooperative patient – do under GA

11. PlanningPlanning
 Residual Eso-Residual Eso- Distance deviation more thanDistance deviation more than
near MR not be recessednear MR not be recessed
 Secondary Eso-Secondary Eso- Distance deviation more thanDistance deviation more than
near and near less than 10pd needs LRnear and near less than 10pd needs LR
advancing in operated eye, LR res in unoperatedadvancing in operated eye, LR res in unoperated
eyeeye
 Secondary ExoSecondary Exo – Due to slipped MR will need– Due to slipped MR will need
excision of psuedotendon & advancing MRexcision of psuedotendon & advancing MR

12. PlanningPlanning
 IO ResurgIO Resurg – iatrogenic mydriasis /bleeding– iatrogenic mydriasis /bleeding
 Vertical residual deviationVertical residual deviation larger in upgaze-larger in upgaze-
SR/IO SurgSR/IO Surg
 Res incyclodviation-Res incyclodviation- tenect ant SO or SRtenect ant SO or SR
nasal/IR tempnasal/IR temp
 Res excyclotorsion-Res excyclotorsion- Harado Ito or SR temp/IRHarado Ito or SR temp/IR
nasalnasal

13. Horizontal and vertical squint too- maybe due toHorizontal and vertical squint too- maybe due to
verticals not being handled-verticals not being handled-
 15 -25 prism of V pattern in the presence of Io15 -25 prism of V pattern in the presence of Io
overaction can be dealt with IO surgery alone.overaction can be dealt with IO surgery alone.
 Rest has to be dealt with additional horizontalRest has to be dealt with additional horizontal
displacementsdisplacements

14.  Weakening IO’s or tuck of SO’s each correct 15Weakening IO’s or tuck of SO’s each correct 15
prism to 25 prism of a V patternprism to 25 prism of a V pattern
 Bilateral superior oblique tenotomies correct 35-Bilateral superior oblique tenotomies correct 35-
45pd of A pattern45pd of A pattern

15. Collapse of V patternCollapse of V pattern Prisms of V correctedPrisms of V corrected
IO weakeningIO weakening 15-2515-25
Tuck So OUTuck So OU 15-2515-25
Vertical shift of horizontal rectiVertical shift of horizontal recti 20-2520-25
Weaken IO OU and verticalWeaken IO OU and vertical
shift of horizontal rectishift of horizontal recti
25-3025-30
SO tuck and IO weakeningSO tuck and IO weakening 40-5040-50

16. Postop
Twice operated residual Exo

17.  Sensory strabismus mainly sensory exotropiaSensory strabismus mainly sensory exotropia
 Do FDTDo FDT
 Release the restrictions and do maximum recess-Release the restrictions and do maximum recess-
resectresect
 Inferior Oblique and SO can be weakenedInferior Oblique and SO can be weakened
which are additional abductors.which are additional abductors.
 Raab, unilateral 4 muscle study for large angle exotropia,Raab, unilateral 4 muscle study for large angle exotropia,
Ophthal, 1979: 86, 1441Ophthal, 1979: 86, 1441

18. Consecutive Exo operated twiceConsecutive Exo operated twice
earlierearlier

19. PostopPostop

20. CarefulCareful
 Scar tissueScar tissue
 Pulled plicaPulled plica
 Suture granulomaSuture granuloma
 Fat adherenceFat adherence
 Muscle ruptureMuscle rupture
 Anterior segment ischaemiaAnterior segment ischaemia
 Congenital absence of SO and IRCongenital absence of SO and IR

21. Suture GranulomaSuture Granuloma

22. Inferior oblique adherence syndromeInferior oblique adherence syndrome
 Hypotropia in the primary position andHypotropia in the primary position and
limitation of elevation in adduction in a eye thatlimitation of elevation in adduction in a eye that
has undergone inferior oblique weakening.has undergone inferior oblique weakening.
 Post Tenon’s capsule should be left intact, ifPost Tenon’s capsule should be left intact, if
orbital fat is encountered should be repositedorbital fat is encountered should be reposited
behind it and defect closed with 8-0 vicrylbehind it and defect closed with 8-0 vicryl
 Bleeding controlled with careful cautery, notBleeding controlled with careful cautery, not
excessive as it can cause adhesions, scarring andexcessive as it can cause adhesions, scarring and
scleral meltscleral melt

23. Operated RE IO anteriorisation presenting with Exo and IOOA Left eye

24. For very tight musclesFor very tight muscles
 Place sutures 0.5 to 1mm behind the muscle duringPlace sutures 0.5 to 1mm behind the muscle during
recession and a like amount behind the muscle clamp.recession and a like amount behind the muscle clamp.
 Scleral track at least 1.5mm long including superficialScleral track at least 1.5mm long including superficial
scleral fibres and at least 2 mm deep.scleral fibres and at least 2 mm deep.
 Limit the dissection of intermuscular membraneLimit the dissection of intermuscular membrane
anterior to its emergence through Tenon’s capsuleanterior to its emergence through Tenon’s capsule
 Use phenylephrine to blanch Tenon’s and episclera andUse phenylephrine to blanch Tenon’s and episclera and
make red muscle more evidentmake red muscle more evident
 Simple perforation without prolapse of vitreous or uveaSimple perforation without prolapse of vitreous or uvea
should be left untreated.should be left untreated.

25.  Accurate workupAccurate workup
 Correct choice of surgeryCorrect choice of surgery
 Proper executionProper execution
 Surgeon’s ability to learn from experienceSurgeon’s ability to learn from experience

26.  It is better to do a wrong procedureIt is better to do a wrong procedure
well than to do the correct procedurewell than to do the correct procedure
poorly!!poorly!!
 Best to do the correct procedure andBest to do the correct procedure and
do it welldo it well

27.  Reop expected in 5-10% of patients whoReop expected in 5-10% of patients who
undergo squint surgeryundergo squint surgery
 Any reop introduces a 33% probability of yetAny reop introduces a 33% probability of yet
another procedureanother procedure

28.  Talk to the patient immediately before surgery andTalk to the patient immediately before surgery and
inform the outcomeinform the outcome
 We will make 100% effort to make this the last squintWe will make 100% effort to make this the last squint
surgery neededsurgery needed