| Identifier |
Thyroid_Associated_Orbitopathy |
| Title |
Thyroid Associated Orbitopathy |
| Creator |
Shirley H. Wray, MD, PhD, FRCP |
| Affiliation |
(SHW) Professor of Neurology, Harvard Medical School; Director, Unit for Neurovisual Disorders, Massachusetts General Hospital, Boston, Massachusetts |
| Subject |
Lid Lag; Bilateral Exophthalmos; Restrictive Orbitopathy of Graves' Disease |
| History |
The classical eye signs of thyroid associated ophthalmopathy (TAO) of Graves' Disease is illustrated by case ID925-4. This 50 year old woman with TAO is included in the collection because she illustrates very well lid lag (persistent elevation of the upper eyelid in downgaze) - von Graefe sign Eyelid position is coordinated with vertical eye movements. In upgaze the lids elevate. In downgaze the lids typically relax and follow the globe down and close. In TAO, in addition to patients with dorsal midbrain lesions (ID 921-1, 924-2 and 925-4) the normal relationship is impaired and the eyelids remain elevated while the eyes move down. The presence of lid-lag in downgaze without significant lid retraction in primary gaze suggests a separate central mechanism for the control of the upper eyelid on downgaze. Galetta et al suggests that one possible lesion for lid-lag without retraction involves the inhibitory connection from the supranuclear downgaze centers to the central caudal nucleus. In addition this patient had 1. Minimal bilateral exophthalmos 2. Slight reduction of orbital resilience 3. Congested scleral blood vessels 4. Slight limitation of upgaze 5. Absent Bell's reflex (eyes fail to move up under closed lids consistent with a restrictive orbitopathy and tethering of the globe inferiorly) Neuro-ophthalmological examination was otherwise completely normal and ruled out compression of the optic nerve by enlarged extraocular muscles crowding the orbital apex. CT Orbit The inferior rectus and medial rectus muscles were enlarged. The scan confirmed the diagnosis of TAO. |
| Anatomy |
Orbit - enlargement of extraocular muscles |
| Pathology |
Graves' Disease is an autoimmune condition. For unknown reasons, the extraocular muscles develop lymphocytic and plasmacytic infiltration with secondary production of acid mucopolysaccharides. In the acute stages, the changes are largely inflammatory. In the chronic inactive stage, there is often fatty infiltration of muscles. |
| Disease/Diagnosis |
Restrictive orbitopathy |
| Clinical |
The video of this patient with TAO of Graves' Disease draws attention to eyelid function. It illustrates very well von Graefe sign - lid lag. Also illustrated is: • The use of a Hertel exophthalmometer to measure the forward protrusion of the proptotic eye • How to evaluate reduced orbital resilience by digital pressure on the globe Note the persistent elevation of the upper eyelid as the eyeball moves down. Lid lag is particularly remarkable in this patient because she has minimal proptosis and minimal lid retraction of the right eyelid. The sclera is not visible between the superior limbus and the upper eyelid. Bilateral inferior scleral show is present. ID925-4, a case of restrictive orbitopathy in Graves' Disease should be viewed alongside this case. |
| Presenting Symptom |
Prominent eyes |
| Ocular Movements |
Lid Lag; Restricted Upgaze |
| Neuroimaging |
Computerized tomography (CT) of the orbit is the gold standard for the diagnosis of TAO. The classic findings are : 1. Enlargement of the extraocular muscle belly with relative sparing of the tendon. 2. Proptosis may be recognized without extraocular muscle enlargement, presumably resulting from an increased volume of intraorbital fat. 3. Enlargement of the lacrimal gland 4. Eyelid soft tissue swelling. CT orbits: Illustrative images in another case of TAO show: Figure 1 Axial CT through the orbit without contrast shows enlargement of the medial rectus muscle bilaterally. Note that the tendinous insertion is spared. Figure 2 The coronal CT (reformatted from axial data set) without contrast shows enlargement of the medial rectus muscle, inferior rectus muscle and upper muscle complex on both sides. Courtesy of Hugh Curtin, M.D. |
| Treatment |
Treatment of TAO associated with Graves' Disease is extremely successful. Irritation and swelling can be treated with a short (1-2month) course of systemic corticosteroids or with low-dose (1500 to 2000 cGy) orbital radiation therapy. Proptosis can be treated with orbital decompression using a variety of techniques. (For a full discussion of therapy see reference 3, 6 and 10) |
| Etiology |
Autoimmune disorder |
| References |
1. Bahn RS, Heufelder AE, Pathogenesis of Graves' ophthalmopathy. N Engl J Med 1993;329:1468-1475. http://www.ncbi.nlm.nih.gov/pubmed/8413459 2. Galetta SL, Gray LG, Raps EC, Shatz, NJ. Pretectal eyelid retraction and lag. Ann Neurol 1993;33:554-557. http://www.ncbi.nlm.nih.gov/pubmed/8498833 3. Galetta SL, Raps EC, Liu GT, Saito NG, Kline LB. Eyelid lag without eyelid retraction in pretectal disease. J Neuro-ophthalmol 1996; 16:96-98. http://www.ncbi.nlm.nih.gov/pubmed/8797164 4. Hoffman PN. In Walsh and Hoyt's Clinical Neuro-Ophthalmology, 6th edition. Editors Miller NR, Newman NJ, 2005;1(22):1085-1131. 5. Jacobson DM. Acetylcholine receptor antibodies in patients with Graves ophthalmopathy. J Neuro-ophthalmol 1995;15:166-170. http://www.ncbi.nlm.nih.gov/pubmed/8574362 |
| Language |
eng |
| Format |
application/pdf |
| Format Creation |
Microsoft PowerPoint |
| Type |
Text |
| Relation is Part of |
925-4; 004-3 |
| Collection |
Neuro-Ophthalmology Virtual Education Library: Shirley H. Wray Collection: https://novel.utah.edu/Wray/ |
| Publisher |
North American Neuro-Ophthalmology Society |
| Holding Institution |
Spencer S. Eccles Health Sciences Library, University of Utah |
| Rights Management |
Copyright 2002. For further information regarding the rights to this collection, please visit: https://NOVEL.utah.edu/about/copyright |
| ARK |
ark:/87278/s6y0j6xs |
| Setname |
ehsl_novel_shw |
| ID |
2174242 |
| OCR Text |
Show %20925-4 viewer 700 100 85 /ehsl-shw 0 5 1 925-4 Thyroid Associated Orbitopathy (TAO) Classical Signs : TAO A prominent stare. Retraction of all four eyelids Bilateral exophthalmos Hertel exophthalmometer 25 OD, 28 OS, base 108. Tight orbits/reduced orbital resilience Prominent congested scleral blood vessels A visible rim of sclera on gentle eye closure Eye movements Lid lag (persistent elevation of the upper eyelid in downgaze) – von Graefe sign Marked limitation of upward gaze Mild limitation of downgaze Restricted horizontal eye movements Positive forced duction test TAO – Limited Upgaze Limitation of upgaze is due to tethering of the eyeball in the floor of the orbit by soft tissue changes. Tethering of the eyeball inferiorly can be confirmed by a forced duction test. TAO Duction Test: Anesthetize the eye with topical anesthesia Push on the globe with a cotton tip swab or Pull with blunt tweezers to try to move eye up. Mechanical restriction - a positive forced duction test. Compressive Optic Neuropathy Most serious complication Crowding of the orbital apex by enlarged ocular muscles Present in 50% severe cases TAO May require urgent orbital decompression Figure 1 Axial CT through the orbit without contrast shows enlargement of the medial rectus muscle bilaterally. Note that the tendinous insertion is spared. Figure 2 The coronal CT (reformatted from axial data set) without contrast shows enlargement of the medial rectus muscle, inferior rectus muscle and upper muscle complex on both sides. Courtesy of Hugh Curtin, M.D. http://www.lib.med.utah.edu/NOVEL |
| Reference URL |
https://collections.lib.utah.edu/ark:/87278/s6y0j6xs |
