Squint surgeries

An overview of basic squint surgeries , their indications, guidelines, procedures and complications

1. Squint Surgeries Dr. Gauree Krishnan DNB 2 nd year Ahalia Foundation Eye Hospital

2. Indications

3. Optimal time for squint surgery Depends on Type of squint Age of the patient Various sensory adaptations

4. In children too young for orthoptic treatment (<4 to 5 yrs) Constant squint- Intermittent squint – Concomitant Squint

5. In children old enough for orthoptic treatment (>4 to 5 yrs) Initially all optical & orthoptic treatments tried to treat the associated sensory adaptation ( supression , amblyopia, ARC) In the presence of ARC  early surgery  good cosmetic & functional results In the absence of true fusion  early surgery for cosmetic reasons  fusion may develop

6. In older children (>12yrs) and adults Can be decided at leisure as only cosmetic prognosis

7. Paralytic Squint Timing : Not too early (as may resolve spontaneously) Not too late ( may keep detoriating ) Ideally after 3 to 6 months

8. Common surgical techniques

9. Muscle Weakening Procedures

10. Muscle Weakening Procedures

11. Muscle Weakening Procedures

12. Muscle Strengthening Procedures

13. Procedures that change direction of muscle action

14. General Considerations

15. Guidelines

16. Anaesthesia

17. Surgical steps

18. Fixation of globe For Hz rectus – 6 or 12 o’ clock For Vt rectus – 9 or 3 o’ clock For IO muscle- 4 ½ o’ clock in left eye 7 ½ o’ clock in right eye After fixing eyeball is rotated away from the muscle being operated

19. Conjunctival incision and exposure of the globe

20. Recession of medial rectus Limits: 3mm to 7-8 mm

21. Recession of lateral rectus LR should be preferably hooked from the superior border side Close proximity of the inferior oblique insertion to the inferior border LR Limits: 5mm to 8-10 mm

22. Recession of superior rectus Care should be taken to avoid accidental hooking of superior oblique muscle

23. Recession of inferior rectus Careful dissection of intermuscular septum and all fascial connections between IR and Lockwood’s ligament as far posteriorly as possible Avoid injury to nerve to inferior oblique, which enters the muscle just as it passes lateral border of IR muscle

24. Hang back recession of rectus muscle Type of non adjustable suspension recession technique Performed for up to 7 mm of recessions Comparatively safer and equally effective

25. Hang back recession of rectus muscle

26. Hang back recession of rectus muscle

27. Hemi Hang back recession of rectus muscle

28. Advantages of hangback and hemi hangback

29. Resection of medial rectus

30. Limits of rectus muscle resection Rectus Maximal (mm) Minimal (mm) Medial 8-10 4 Lateral 12- 14 4- 5 Superior 5- 6 2- 3 Inferior 5- 6 2- 3

31. Marginal Myotomy

32. Faden’s Operation

33. Indications of Faden’s operation To correct DVD Patients having incomitant strabismus with orthotropia in primary position To treat upshoot and downshoot of the adducted eye in patients with Duanne’s retraction syndrome Type 1 Near Esotropia with high AC/A ratio Persistent eso after max recession and resection surgery To dampen nystagmus in Nystagmus blockage syndrome Efficacy  {MR > Vertical recti > LR}

34. Faden’s Operation Advantages Decreased chances of over adduction ( sp in non accommodative convergence excess) Post-op FDT is free Saves the ciliary vessels from damage Disadvantages Needs vigorous traction for suture application Vortex vein injury Higher globe perforation chances Variable results

35. Inferior Oblique weakening procedures Indications Primary IO overaction Secondary overaction of IO following SO palsy Double elevator palsy – IO weakening indicated in the other eye Upshoots in Duanne’s retraction syndrome Types of procedures Disinsertion Myectomy - excision of a segment of muscle belly Extirpation- almost complete removal of muscle Recession Park Fink Elliot and Nankin Recession with anterior transposition- disinsertion and reinsertion near the IR insertion

36. Superior Oblique weakening procedure Indications Unilateral weakening : Brown’s Syndrome Isolated IO muscle weakness Bilateral weakening : With/ without hz muscle surgeryfor A- pattern deviations Causes eso shift of 30-40 prism dioptres in downgaze , little change in primary position and almost no effect in upgaze Procedures Tenotomy Split lengthening of tendon Recession Translational recession of Prieto -Diaz Posterior tenectomy of SO

37. Superior Oblique Tenotomy

38. Translational recession of Prieto -Diaz

39. Posterior tenectomy of SO

40. Superior Oblique strengthening procedure

41. Harada Ito procedure

42. Harada Ito procedure

43. Superior Oblique Tuck Indications: SO paresis DVD Note: A transient post op pseudo Brown Syndrome due to limitation of elevation of adducted eye

44. Muscle Transposition Procedures Moving the EOM out of their original planes of action Generally for paralytic strabismus Indications: III, VI and double elevator palsies A- , V- patterns Cyclodeviations Small hz and vt deviations

45. Knapp procedure

46. Jensen’s Procedure

47. Hummelsheim procedure

48. complications

49. Complications of anaesthesia Cardiac arrest Malignant hyperthermia Hepatic porphyria and suxamethonium sensitivity Oculorespiratory reflexes Succinyl choline induced apnea

50. Intraoperative complications

51. Post operative complications Infections Endophthalmitisorbital cellulitis Localized suture abcess Suture reaction Conjunctival granuloma Conjunctival cyst Due to inadvertent closure of conjunctiva in the wound

52. 5) Anterior segment ischaemia Cause Disruption of blood supply to the anterior segment from anterior ciliary arteries Signs Corneal oedema Stromal swelling DM folds Heavy AC reaction Cataractous lens Prevention All 4 recti should never be disinserted simultaneously Period of 6 months bewteen hz and vt muscle surgeries Muscle slpitting procedures Modified tucking procedures

53. Post operative complications Dellen Localised area of conjunctival thinning Commonly due to limbal approach Necrotizing scleritis Refractive error Most commonly astigmatism Diplopia RD Scarring

54. Adhesive syndrome Inferior oblique surgery Under or over- corrections Gaze incomitance Alteration in palpebral fissure Narrowing due to vt muscle resections Large recess resect procedures of hz recti Widening with large vertical recessions Psychological complications

55. Post operative care after strabismus surgery Immediate general care Dressing Topical antibiotic and steroid Oral antibiotics Oral inflammatory Restrictions for the patients Follow up examination Orthoptic treatment

56. Conclusion

57. Refrences Management of squint and Amblyopia John A. Pratt-Johnson Geraldine Tillson Strabismus and paediatric ophthalmology Gary R. Diamond Howard M. Eggers Squint and orthoptics A.K. Khurana

58. Thank You