Thyroid Eye Disease & Other Orbital Conditions

1. Thyroid Eye Disease&Other Orbital Conditions March 11, 2008

2. Thyroid Eye Disease: • Thyrotoxicosis (Graves’ Disease) • Autoimmune disorder • Third or Fourth decade • Women > Men • Euthyroid Graves disease – Eye signs without clinical hyperthyroid (5%).

3. Pathogenesis of Thyroid Eye Disease: • IgG infiltrates the EOM resulting in cellular infiltration into the muscle belly. • Muscle fiber fibrosis leading to restrictive myopathy & diplopia. • Inflammatory cellular infiltration • Increase in the orbital contents

4. Thyroid

5. Enlarged Thyroid

6. Clinical Manifestations of Thyroid Eye Disease: 1) Soft Tissue Involvement: • Periorbital & Lid edema • Conjunctival & episcleral hyperemia • may outline the horizontal rectus muscles. • Chemosis • Dry eye (infiltration of the lacrimal gland).

8. Conjunctival hyperemia around EOM’s:

9. Clinical Manifestations of Thyroid Eye Disease: 2) Proptosis • An abnormal protrusion of the globe. • unilateral or bilateral • symmetrical or asymmetrical • frequently permanent

10. Proptosis:

11. Measuring Proptosis • Measured with an exophthalmometer • Hertel • Readings greater than 20 mm are indicative of proptosis. • A difference of 2 mm is suspicious. • Normal values depends on race & gender.

12. Exophthalmometry in Healthy Adults

14. Pseudo-proptosis: • Facial asymmetry • High myopia or buphthalmos • Lid retraction • Enophthalmos

15. Clinical Manifestations of Thyroid Eye Disease: 3) Lid Retraction: • Fibrosis of the levator. • Sympathetic overstimulation of Mueller’s muscle. • Dalrymple sign- lid retraction in primary gaze. • Von Graefe sign- retraction on downgaze • Kocher sign- stare with attentive fixation

16. Dalrymple Sign:

17. Clinical Manifestations of Thyroid Eye Disease: 4) Optic Neuropathy: • Affecting about 5% of patients with thyroid eye disease • Compression of the optic nerve by the enlarged EOM’s at the orbital apex. • What signs may be involved?

18. Clinical Manifestations of Thyroid Eye Disease: 5) Restrictive myopathy • Affects 30 to 50% of patients with thyroid eye disease. • IOP increase on upgaze (> 4 mmHg) due to fibrotic inferior rectus. • Resistance to retrodisplacement (multiple fibrotic EOM’s) • Absence of Bell’s phenomenon (inferior rectus) • Occurs first due to edema and later due to fibrosis.

19. Clinical Work-up of the Suspected Graves Disease Patient • VA • Exophthalmometry • Resistance to Retrodisplacement of Globe • An Absent Bell’s Phenomenon • Lagophthalmos • Slit lamp • Schirmer’s • Visual Field Testing

20. Imaging Work-up of the Suspected Graves Disease Patient • Looking for the enlarged EOM’s • Can use ultrasound, CT or MRI. • MRI better for soft tissue imaging.

21. Muscle Infiltration:

22. Muscle Infiltration:

23. Classifying Graves Disease (Remember NO SPECS) Class 0 No physical signs or symptoms 1 Only signs 2 Soft tissue involvement 3 Proptosis > 3mm 4 EOM involvement 5 Corneal involvement 6 Sight loss

24. Other Orbital Conditions to Consider

25. Carotid-cavernous fistula: • Communication between the carotid artery and the cavernous sinus. • Venous and arterial stasis around the eye and orbit.

27. Mucocele: • A slowly expanding cystic accumulation of mucoid secretions. • Normal sinus drainage is obstructed • Follows infections, allergies, sinusitis

28. Mucocele EOM restriction:

30. Dacryocystitis vs. Mucocele • Mucocele – A cystic mass usually filled with mucous. Typically arises after sinusitis.

31. Encephalocele: • Herniation of intracranial contents through a congenital defect of the base of the skull. • Usually seen in infancy • Typically involves the superomedial part of the orbit.

32. Cavernous hemangioma: • Most common benign orbital tumor in adults. • Most common in women • Slowly progressive & unilateral • Growth is accelerated during pregnancy • Tumor usually located within the muscle cone.

33. Cavernous hemangioma:

34. Cavernous hemangioma MRI:

35. Preseptal vs. OrbitalCellulitis: Both Conditions show: • Chemosis • Conjunctival injection • Pain • Redness • Swelling of the lids

36. Preseptal: No Proptosis F.R.O.M. of EOM’s Normal Pupils Normal Visual Acuity Orbital: Proptosis Ophthalmoplegia + APD Reduced Visual Acuity Preseptal vs. Orbital Cellulitis: