1. Brown Syndrome

2. Brown syndrome is found in 10% to 24% of patients with vertical muscle paresis.. occur once in every 430 to 450 cases of strabismus.. may be bilateral in approximately 10% of case

4. Shortening of the anterior sheath of the superior oblique tendon. Restriction of the superior oblique tendon at the trochlear pulley Brown syndrome was described by Harold W. Brown in 1949 as the superior oblique tendon sheath syndrome. this theoryabandoned congenitally inelastic or short tendon Abnormal tendon-trochlear complex MECHANISM

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

7. FINDING 1. Deficient elevation in adduction 2. Less elevation deficiency in midline. 3. Minimal or no elevation deficiency in the abducted position 4. Minimal or no SO overaction.. 5. V pattern with divergence in upgaze 6. Restricted forced ductions

8. OTHER FINDINGS 1. Downshoot or hypotropia in adduction 2. Widening of the palpebral fissure on adduction 3. Anomalous head posture 4. Hypotropia in the primary position

9. DIFFERENTIAL DIAGNOSIS 1-I O PALSY 2-DOUBLE ELEVATOR PALSY 3- CONGENITAL FIBROSIS SYNDROM 4-BLOW OUT FX 5-THYROID OPHTHALMOPATY 5-ADHERENCE SYNDROM

10. Brown syndrome Congenital Acquired form Trauma in the region of the trochlea Systemic inflammatory intermittent Brown syndrome, which may resolve spontaneously. Resolution of congenital Brown syndrome is unusual but possible Iatrogenic Brown syndrome

11. Comparison of Inferior Oblique Muscle Palsy With Brown Syndrome Inferior Oblique Muscle PalsyBrown Syndrome Forced ductionsNegativePositive Strabismus patternA patternV pattern Superior oblique muscle overaction Usually presentNone or minimal 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.

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

13. Brown syndrome mildmoderatesevere hypotropia in primary position no yes downshoot of the eye in adduction. noyes chin-up head posture and sometimes by a face turn away from the affected eye in sever cases

14. 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.

15. Management 1.Observation :alone in about two thirds of all Brown syndrome cases 2.rheumatoid arthritis or other systemic inflammatory diseases Systemic treatment 3.Corticosteroids injected near the trochlea 4.Sinusitis has also led to Brown syndrome CT of the orbits and paranasal sinuses

16. 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

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

18. 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

19. 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

20. Brown Syndrome Chicken suture

21. In 1991, Wright described a superior oblique expander procedure for browns syndrome and superior oblique overaction with good results. Originally, this procedure has been performed with silicone band expander.. 9/18/2015 3:26 AM21

22. Brown Syndrome Silicone expander

23. Silicon Expander

24. Elongation with fascia lata

25. Elongation with Achill Tendon