Special Forms of Strabismus

1. Special Forms of Strabismus AbbasAttarzadeh MD Professor of ophthalmology SUMS

2. Duane Syndrome • Retraction of the globe in actual or attempted adduction. • Horizontal eye movement is usually somewhat limited in both directions. • Upshoot or downshoot (leash phenomenon) of the affected eye in attempted adduction co-contraction of the medial and lateral rectus muscles and, alternatively, to slipping of the lateral rectus muscle over the outer aspect of the eye.

4. Most cases of Duane syndrome are sporadic • 5%-10% show autosomal dominant inheritance • A higher prevalence in females

5. In most anatomical and imaging studies, the nucleus of the sixth cranial nerve is absent, and an aberrant branch of the third cranial nerve has innervated the lateral rectus muscle

6. Electromyographic studies have shown: • paradoxical innervation of the lateral rectus muscle (innervation on attempted adduction and reduced innervation on attempted abduction). • Anomalous synergistic innervation of the medial, inferior, and superior rectus muscles and the oblique muscles

7. Although considered an innervational anomaly: Tight and broadly inserted medial rectus muscles Fibrotic lateral rectus muscles, with corresponding forced duction abnormalities, are often encountered at surgery.

8. Clinical Features • Poor abduction, frequently with primary position esotropia • Poor adduction and exotropia • Poor abduction and adduction, with esotropia, exotropia, or no primary position deviation 50%-80% in several series About 15% of cases are bilateral;

9. DDX with sixth nerve palsy • Careful observation for globe retraction on adduction • lack of correspondence between the absent or typically modest primary position esotropia and the usually profound abduction deficit • A further point of differentiation is that, even in esotropic Duane syndrome, a small-angle exotropia frequently is present in gaze to the side opposite the affected eye

10. ManagementIndications for surgery • Primary position deviations • Abnormal head position • Marked globe retraction • Large upshoots or downshoots

11. Duane syndrome with esotropia • Recession of the medial rectus muscle on the involved side • Bimedial rectus recession recommended for deviations over 20∆ in primary position Resection of the lateral rectus muscle for Duane syndrome with esotropia is not favored because of the likelihood that globe retraction will worsen, although one study reported favorable results with unilateral recession-resection procedures

12. Bimedial Rectus Recess

13. Partial or full transposition of the vertical rectus muscles has been advocated to improve abduction but may exaggerate the effects of co-contraction. Posterior scleral fixation of the transposed portions of the vertical rectus muscles, as described by Foster, has been found helpful, no only in Duane syndrome but in several types of paralytic strabismus as well

14. Surgery

15. The value of botulinum injection into the medial rectus muscle to improve abduction is controversial

16. Duane syndrome with exotropia and deficient adduction(type 2) • Recession of the lateral rectus on the involved side for small deviations • Both lateral recti for large deviations with avoidance of resection of the medial rectus The latter aspect is especially important when an up- or downshoot is present on attempted adduction, because this finding indicates severe co-contraction

17. type 3 Duane syndrome who have poor abduction and adduction Severe globe retraction may be helped by: • Recession of both the medial and the lateral rectus muscles • Splitting the lateral rectus muscle in a Y configuration • A posterior fixation procedure on LR • Disinsertion of the lateral rectus muscle and reattachment to the lateral wall of the orbit is the most recent procedure to be tried Have straight eyes in or near the primary position and little, if any, head turn

18. LLR recess 13 mm + Bifurcation LMR Bifurcation

19. Brown Syndrome

20. Brown syndrome was described by Harold W. Brown in 1950 as the superior oblique tendon sheath syndrome. • Shortening of the anterior sheath of the superior oblique tendon. • Restriction of the superior oblique tendon at the trochlear pulley restriction of elevation in adduction abandoned this theory

21. Brown Syndrome Restriction of the superior oblique tendon at the trochlear pulley

22. Brown syndrome bilateral in approximately 10% of cases • Congenital • Acquired form Trauma in the region of the trochlea Systemic inflammatory Resolution of congenital Brown syndrome is unusual but possible intermittent Brown syndrome, which may resolve spontaneously.

23. Comparison of Inferior Oblique Muscle Palsy With Brown Syndrome Deficient elevation in adduction that improves in abduction but often not completely In adduction, the palpebral fissure widens and a downshoot of the involved eye is often seen; it can be distinguished from superior oblique muscle overaction because downshoot in the latter condition occurs less abruptly as adduction is increased.

24. Brown syndrome OS Divergence in upgaze Down shoot in attempted elevation in adduction? Down shoot in attempted elev. in adduct. (different than IO palsy)

25. Brown syndrome chin-up head posture and sometimes by a face turnaway from the affected eye insever cases

26. An unequivocally positive forced duction test demonstrating restricted passive elevation in adduction is essential for the diagnosis of Brown syndrome. • Retropulsion of the globe during this determination stretches the superior oblique tendon and accentuates the restriction. When inferior rectus muscle fibrosis or inferior orbital blowout fracture (the principal entities to be differentiated) produces a restrictive elevation deficiency, the limitation to passive elevation is accentuated by forceps-induced proptosis of the eye rather than by retropulsion.

27. Management • Observation alone in about two thirds of all Brown syndrome cases • rheumatoid arthritis or other systemic inflammatory diseases • Systemic treatment • Corticosteroids injected near the trochlea • Sinusitis has also led to Brown syndrome CT of the orbits and paranasal sinuses

28. Surgical treatment is indicated for the most severe cases • Primary position hypotropia • Anomalous head posture • Iatrogenic superior oblique muscle palsy may occur postoperatively. 44%-82% sheathectomy has been abandoned in favor of ipsilateral superior oblique tenotomy

29. Brown Syndrome SO tenotomy SR SR LR RM MR LR IR IR IO IO

30. Superior oblique muscle palsy Reduced: By careful preservation of the intermuscular septum during tenotomy. This modification often produces an early under correction that gradually improves with time

31. Perform simultaneous ipsilateral inferior oblique muscle weakening. • guarded tenotomy using an inert spacer sewn to the cut ends of the superior oblique tendon • Controlling the gap between the cut ends with an adjustable suture These procedures eliminate the need for simultaneous inferior oblique muscle weakening but sometimes result in a downgaze restriction due to adhesions to the nasal border of the superior rectus muscle. Care must be taken to avoid contact of the spacer to nearby structures by preserving the intermuscular septum

32. For those surgeons who are a little too chicken to completely cut the SO tendon and cause a SO palsy…Chicken suture technique

33. Brown Syndrome Chicken suture

34. For those surgeons with a sense of humor…Try the rubber chicken trickaka silicone expander

35. Brown Syndrome Silicone expander

36. Facia Lata

37. Third Cranial (Oculomotor) Nerve Palsy

38. Traumatic 3rd N palsy

39. The causes of third cranial nerve palsy in children Congenital disorders (40%-50%) • Trauma • Inflammation • Viral infection • Migraine • (Infrequently) neoplastic lesions Adults • Intracranial aneurysm • Diabetes, • Neuritis • Trauma • Infection • Rarely, tumor Diabetic third cranial nerve palsy generally resolves spontaneously within 3-4 months. The majority of adults referred for surgical treatment have palsy due to trauma

40. Clinical Features Limited: • Adduction • Elevation • Depression • Exotropia and often Hypotropia • Upper lid ptosis usually is present, often with a pseudoptosis

41. Aberrant regeneration (misdirection)

42. Niknam Farshad 23 yo accident 4years ago 3rd nerve palsy aberrant regeneration

43. Management Except in congenital cases of third cranial nerve palsy, it is advisable to wait 6-12 monthsfor any spontaneous recovery before surgical correction is planned. Patients with at least partial recovery are much better candidates for good functional, as well as cosmetic, results,

44. Cured III N palsy

45. Third cranial nerve palsies present difficult surgical challenges because multiple extraocular muscles as well as the levator may be involved. • Replacing all of the lost rotational forces on the globe is impossible; therefore, the goals of surgery must be thoroughly discussed • With patients so their expectations are realistic, Adequate alignment for binocular function in primary position and in slight downgaze for reading may be all that can be expected.

46. Sadravy Bahareh post surgery rt 3rd N palsy 15 years po 9.3.86

47. surgical procedure • A large recession-resection procedure on the horizontal rectus muscles to correct the exodeviation, with supraplacement of both to correct the hypotropia • Most surgeons reserve correction of ptosis for a subsequent procedure • Some surgeons use superior oblique tenotomy instead of supraplacement of the horizontal rectus muscles for hypotropia

48. Sixth nerve palsy.ppt Sixth Cranial (Abducens) Nerve Palsy

49. motility disturbances Graves Eye Disease

50. Edema, inflammation, and fibrosis are present in this disease because of lymphocytic infiltration. These conditions result in massive enlargement of affected extraocular • muscles and may not only restrict motility but also cause compressive optic neuropathy.