1. Presenter Dr. Bikram B Thapa Moderator Dr. Savleen Kaur Chairperson Dr. Jaspreet Sukhija

2. Aim To discuss a case of traumatic sixth nerve palsy and its management. 3. Chief complaints 25 year male DOP 04.07.2014 C/o double vision since 2 months. 4. History of presenting illness History of double vision since 2 months Sudden in onset Disappears on closing one eye Present in primary and left lateral gaze Constant in nature - No diurnal variation Associated with inward deviation of left eye and inability to move left eye outward constant deviation, not progressed/improved 5. Past history A H/O fall from moving train 2 months back when he sustained injury to left side of the head H/O loss of consciousness, admitted and treated outside conservatively CT scan showed multiple parietal bone fractures with temporo- parietal extra-dural haematoma. 6. No h/o similar complaints in the past No h/o prior ocular surgery No h/o any systemic illness No h/o squint in family No h/o treatment taken 7. Examination (04.O7.2014) OD OS Visual acuity 6/6 6/6 IOP 10 mm Hg 12 mm Hg Lids and adnexa WNL WNL EOM Photos Photos Anterior segment WNL WNL Posterior Segment WNL WNL 8. Squint examination Head posture: face turn to left 9. Measurement of ocular deviation Hirschberg test Reflex in L/E falls at the pupillary margin on temporal side indicating 15 degrees of esotropia in LE 10. Cover test Video 11. Extra-Ocular movements: versions 12. LIMITED LIMITED DUCTIONS- ocular movements remained the same with no improvement in abduction LIMITED 13. Abduction deficit grade -4 GRADES: -1= can rotate eye from midline to 75% of full rotation -2= can rotate eye from midline to 50% of full rotation. -3= can rotate eye from midline to 25% of full rotation -4= can rotate eye upto midline but not beyond it -5= cannot rotate eye from opposite field to midline Scott AB Kraft SP Botulinum toxin injection in the management of lateral rectus paresis. Ophthalmology. 1985;92676- 683 14. Prism Bar Cover Test ( primary deviation) for near and distance 0 35 BO 45 BO 0 35 BO 45 BO 0 35 BO 45 BO ALL VALUES IN PRISM DIOPTERS 15. PBCT (secondary deviation) for near and distance 0 45 BO 55 BO 0 45 BO 55 BO 0 45 BO 55 BO ALL VALUES IN PRISM DIOPTERS 16. SENSORY EVALUATION 17. Worth 4 dot test distance and near 2 RED AND 3 GREEN seen simultaneously s/o Diplopia 18. Diplopia charting Red- RIGHT EYE Green LEFT EYE AS THE PATIENT SEES IT at 1 m; uncrossed horizontal diplopia maximum diplopia in Left lateral gaze; distal image belongs to left eye BSV1 INCH 2 INCHES L R 19. Stereopsis Titmus fly test Couldnt appreciate flying wing of titmus fly s/o Absence of gross stereopsis 20. SUMMARY 25 Yr male with h/o head trauma followed by diplopia since 2 months. VA was 6/6 with normal anterior and posterior segment both eyes. Left eye showed an esotropia with abduction deficit grade 4. Primary Deviation measured was 35 PD and secondary deviation was 45 PD esotropia in primary gaze by PBCT. Diplopia charting showed binocular uncrossed horizontal diplopia, maximum in left lateral gaze. Sensory examination showed diplopia on Worth four dot test and absence of gross stereopsis. 21. CLINICAL DIAGNOSIS Left Eye ACQUIRED (POST TRAUMATIC) SIXTH NERVE PALSY Right Eye WNL 22. TESTS OF MUSCLE FUNCTION Forced Duction Test : Negative for medial rectus left eye (No Medial rectus contracture present) Force Generation Test : FOR left eye lateral rectus Weak generated force 23. Final diagnosis L/E Acquired post traumatic sixth nerve palsy with no secondary medial rectus contracture 24. Management Conservative management Right eye fogged glasses for working hours Used in front of the normal eye so as to stimulate movement of the paretic and thus prevent the development of contracture of the antagonist. On regular follow up. 25. Follow up 1. Whether diplopia is improving or worsening. 2. Amount of esotropia ( increasing or decreasing). 3. Grade of abduction limitation 4. Any new neurological symptom or sign. 5. Compliance to the treatment given. 26. Course of post traumatic sixth nerve palsy Overall recovery 73-83% at the end of 6 months (unilateral 84%, bilateral 38%) Recovery rate related to severity at initial examination The median time to recovery is 90 days Upto 3% may require surgery Holmes et al.J AAPOS 1998;2:265-8 27. Predictors of non recovery Nonrecovery - presence of diplopia in primary position or more than 10 prism diopters of esotropia in primary position, at 6 months from onset. 1. Complete paralysis (inability to abduct till midline; abduction deficit grade -4 or -5) 2. Bilateral involvement Holmes et al. Ophthalmology 2001;108:14571460 28. Indications of neuroimaging in traumatic sixth nerve palsy in adults 1. At the first visit 2. Progression in esotropia 3. Diplopia worsening. 4. Presence of additional neurologic signs or symptoms. Goodwin et al. Optometry 2006;77:534-539 29. Trauma as cause of six nerve palsy Etiologies of acquired VI nerve palsy Schrader et al Rucker et al Johnston et al Robertson et al Rush et al Potel et al Bagheri et al Trauma 3% 12% 32% 20% 17% 12% 18% neoplasm 7% 33% 13% 39% 15% 5% 2% Aneurysm 0 3% 1% 3% 3% 2% 0 Ischemia 36% 8% 16% 0 18% 16% 1% Miscellaneo us 30% 24% 30% 29% 18% 19% 6% Undetermin ed 24% 20% 8% 9% 29% 26% 6% Miscellenious = migraine, multiple sclerosis, pseudotumor cerebri as non localising sign Azarmina et al.J Ophthalmic and vision research 2013;8:160-171 30. Causes of 6th nerve palsy in trauma The abducens nerve is particularly vulnerable to trauma because of its long intracranial course. At the apex of the petrous part of the temporal bone. It may be stretched as it passes from the brainstem to its entry to the dura at the basilar process by downward and forward displacement of the brain stem. Fracture of the cranial floor causing compression on nerve Meningeal oedema, or Inflammation in the skull base. Hollis et al. J Accid Emerg Med 1997;14:172-175 31. PLAN OF MANAGEMENT Tests of muscle function- to identify medial rectus contracture Fracture of left parietotemporal bone Biconvex hyperdense lesion Just beneath the fractured bone s/o extradural 32. Non surgical therapy Prisms- Deviation of 10-15 PD can easily be corrected by prisms. Fogged glasses With large angle incomitance where it can not be corrected by prisms. Used in front of the normal eye so as to stimulate movement of the paretic and thus prevent the development of contracture of the antagonist. 33. Surgical therapy Indications: If paralysis is of recent onset, 6-8 months of waiting period is mandatory for the condition to be considered stable. During the waiting period patient is evaluated at frequent intervals and visual comfort maintained with prisms or unilateral occlusion 34. Discussion Paralytic Non paralytic Age of onset late childhood Type of onset sudden gradual Inciting causes Head trauma, systemic illness absent Diplopia present absent Head posture present absent Incomitance present absent Limitation of movement present absent Difference in primary and secondary deviation present absent Sensory adaptation absent present Sixth nerve palsy has been reported to be the most common type of extra ocular nerve paralysis Rush JA, Younge BR. Arch Ophthalmol1981;99:76-79 35. Surgeries of paretic muscle Botulinum toxin injection in the antagonist. Recovery rate at 6 months is as same as conservatively managed patients (73% versus 71% in the conservatively managed group) LR resection with MR recession. Recession of the contralateral MR is often needed to increase the diplopia free field and to reduce incomitance. 36. Surgeries of the paralytic muscle Treated with vertical rectus transposition procedures combined with MR recession. Increased risk of anterior segment ischaemia. 20-30% risk of vertical misalignment. 37. Surgical options for sixth nerve palsyUnilateral recession and resection Unilateral recession and resection with contralateral MR recession. Single muscle recession/resection upto 20 PD Unilateral recession resection upto 40 PD Larger deviation>40 PD= Combine with C/L MR recession ADV: Easy to perform/no risk of ant seg. ischemia DISADV: binocular fields reduced ; undercorrection 38. Partial vertical rectus transposition +MR weakening (HUMMELSHEIM PROCEDURE) Full vertical rectus transposition +MR weakening ( O Conner) Rectus muscle union + MR weakening (JENSEN) Combine with MR recession if ET>25 PD ADV: Improves abduction; when R-R fails DISADV: Ant seg ischemia; overcorrection 39. Limited abduction Duction upto midline Force generation test no force transposition Mild to Moderate force Recession/resection Duction past midline Recession/resection 40. INCOMITANT STRABISMUS : CLASSIFICATION AND INVESTIGATION Definition:a strabismus where the angle or degree of the deviation varies in different directions of gaze OR with each eye fixing (ie the secondary deviation is greater than the primary deviation). 41. Paralytic strabismus clinical features Incomitance Limitation of movement of eye in the field of action of extraocular muscle Secondary deviation greater than the primary deviation 42. Inclusion criteria 1. Initial examination _20/200 in each eye 6. Distance esotropia at least >10 PD 7. Absence of a third nerve palsy 8. Absence of treatment with botulinum toxin or surgery TABLE 2. Patient demographics, palsy characteristics, and recovery rates All Unilateral Bilateral palsies palsies palsies 1. Number of patients 33 25 8 2. Median age (y) 20 18 22.5 3. Complete palsy 16 (48%) 10 (40%) 6 (75%) 4. Median severity of NA -3 -8 abduction deficit 5. Spontaneous recovery 24 (73%) 21 (84%) 3 (38%) 6. Median time to 91 90 92 documented recovery (d)