]. CJin. Neuro-ophthalrnol. 3: 67-74, 1983.

Orbital Myositis

THOMAS C. SPOOR, M.D., M.5. WALTER C. HARTEL, M.D.

copy. B-scan ultrasonography revealed a markedly Abstract enlarged medial rectus, better demonstrated by We report five cases of presumed orbital myositis computed tomography (Fig. 3a). There was no mimicking extraocular muscle motility disturbances other evidence for orbital pathology or involve­ and manifesting clinical signs of active inflammation ment of the adjacent sinuses (Fig. 3b). She was over the involved muscles. Computed tomographic treated with 80 mg prednisone daily with a rapid evidence for exraocular muscle enlargement is helpful resolution of both pain and proptosis. Steroids in confirming the diagnosis. If not present or atypical, another etiology should be sought. All patients re­ were tapered over 8 weeks. Three weeks later, sponded rapidly and dramatically to systemic cortico­ while taking 40 mg prednisone per day, she was steroids. Anterior inflammation may be accompanied asymptomatic except for mild restriction of abduc­ by iritis and respond to topical corticosteroids. We tion of the right eye. Examination was otherwise believe the diagnosis of orbital myositis may be made negative. Two weeks later, while taking prednisone on clinical grounds with confirmation by computed 10 mg per day, there was still limitation of ocular tomographic evidence for extraocular muscle enlarge­ abduction. Eight weeks after presentation, she was ment and clinical response to corticosteroids. Biopsy is asymptomatic and extraocular motility was normal. unnecessary except in atypical cases. Prednisone was discontinued and she has remained asymptomatic for the past 6 months.

Introduction Case 2 The diagnosis of orbital myositis implies orbital A 16-year-old boy was referred with a diagnosis inflammation confined to one or two extraocular of orbital cellulitis. He related a 2-day history of muscles and may represent a distinct clinical entity pain and swelling of the right periorbital region. mimicking a paretic extraocular muscle of acute Afferent visual function was normal. Examination onset, with restricted ductions. It is responsive to revealed 4 mm of right proptosis, swelling, and systemic corticosteroids" ~ We report five patients erythema of the right orbit, and mild limitation of with acute extraocular motility dysfunction pre­ abduction and adduction of the right eye (Fig. 4). sumably due to orbital myositis. The diagnosis, Neuro-ophthalmologic examination was otherwise based upon suspicion, clinical presentation, and normal. B-scan ultrasonogram demonstrated en­ computed tomographic evidence, was confirmed largement of the right medial rectus. Computed by rapid resolution after treatment with systemic tomography (Figs. 5a and 5b) demonstrated an corticosteroids. enlarged medial rectus and a diffuse right pansi­ nusitis involving the right frontal, ethmoid, and Case 1 maxillary sinus. He was treated with 80 mg of prednisone daily with resolution of orbital and A 37-year-old woman presented with a swollen, sinus abnormalities over 48 hours. Steroids were painful right eye and horizontal diplopia. Her rapidly tapered and decreased over a 2-week pe­ symptoms had increased for 3 weeks prior to re­ riod. He has remained asymptomatic. Computed ferral. She denied any antecedent upper respiratory tomography 4 months later documented normal infection or history of sinusitis. Examination re­ orbits and paranasal sinuses. vealed 20/15 acuity in each eye. The right eye was restricted in both abduction and adduction (Fig. 1). Case 3 The conjunctiva over the medial rectus was in­ flamed (Fig. 2). Six millimeters of proptosis were A 53-year-old woman was referred with a 1­ present in the right eye. Slip lamp examination and week history of pain in the left eye increasing with intraocular pressures were normal as was fundus- abduction. She was treated by her family physician with intramuscular penicillin and oral erythromy­ cin for a "blocked tear duct." When she failed to From the Department of Ophthalmology. University of South improve, she was referred for evaluation. No other Carolina School of Medicine. Columbia, South Carolina. significant history was elicited. Visual acuity was

March 1983 67 Orbital Myositis

Figure 3 ... Computed tomogr.m demonstrating marked en­ I.rgement ()f right medial rectus.

Figure 1. Restriction of both ocular abduction and adduction due to enlarged. myositic. right medial rectus.

figure 3D. C()ronal reconstruction demonstrating isolated in­ volvement of right medial rectus and absence of ,)djacent sinus involvement

examination, intraocular pressures and funduscopy were normal. B-scan ultrasonography revealed a mass in the Figure 2. Loc.lized conjunctiv.1 infl.mmatil)n lwerlying medi.1 superomedi.11 orbit. Computed tomography dem­ rectus acutelv Inflamed bv orbital myositis. onstr.1ted a well-circumscribed mass in the super­ omedial orbit adjacent to and contiguous with the medi.l1 rectus (Fig. 7.1); after injection of contrast, unimpaired. There were no localizing pupillary ring enhancement was evident (Fig. 7b). There was signs. The left orbit was exquisitely tender to pal­ no computed tomographic or x-ray evidence for pation. A partial left ptosis was present. Extraocular bony destruction or involvement of the adjacent motility was restricted in elevation and abduction sinus. (Fig. 6). There was obvious inflammation over the She was treated with 80 mg prednisone per day. superomedial portion of her left globe. Two milli­ Within 24 hours she was pain-free; after 72 hours meters of left proptosis were present. Slit lamp she was asymptomatic. Prednisone was decreased

68 Journal of Clinical Neuro-ophthalmology Spoor, H.lrtel

to 40 mg per day. Two weeks later, she was totally asymptomatic and her ophthalmic examination was normal. B-scan ultrasonography revealed the acoustically homogeneous medial orbital mass to be markedly decreased in size. Prednisone was rapidly tapered and discontinued over a 6-week period. She remained asymptomatic. A repeat computed tomography was obtained 6 weeks after her initial scan and demonstrated a marked reduc-

Figure 4. Periorbital swelling and mild limitation of ocular (b) abduction and adduction, right eye.

Figures 5 .. and 5 b. Computed tomogr.lm, (axial .]TId coronal reconstruction) demonstrating enlargement of the right medial rectus and adJacent ethmoid Si­ nusitis.

(a)

March 1983 69 Orbital Myositis

of the globe was inflamed. Forced ductions were positive in the right eye confirming the presence of a pseudo-Brown's syndrome. The remainder of the ocular and orbital exam was normal. There was no x-ray evidence for sinusitis. A diagnosis of superior oblique myositis was made. She was treated with 80 mg prednisone per day with rapid resolution of her symptoms. Four days later, ex­ amination was normal. Steroids were rapidly ta­ pered over 2 weeks. She was asymptomatic for 7 months. She then presented with mild iritis and a recurrent pseudo-Brown's syndrome. Both re­ sponded to topical 1% prednisolone acetate over a 2-week period. Three months later, her superior oblique myositis recurred accompanied by supe­ rior periorbital edema. Orbital computed tomog­ raphy was negative, except for soft tissue swelling in the vicinity of the trochlea. She again responded to topical prednisolone acetate and is presently asymptomatic on a maintenance dose of topical prednisolone acetate twice daily.

Case 5 A 10-year-old girl was referred for evaluation of ptosis. Three weeks prior to evaluation, she awoke with a ptotic upper lid. Over the next 2 weeks, mild swelling and tenderness developed. After a negative laboratory and neuroradiologic evalua­ tion, she was hospitalized and treated with in­ Figure 6. Orbital myositis presenting as a partial third and sixth travenous ampicillin for presumed orbital cellulitis. cr.lniitl nerve paresis. When the swelling and erythema increased, she was referred for neuro-ophthalmologic consulta­ tion in the size of the mass and loss of peripheral tion. enhancement (Fig. 8a). The mass appeared contig­ No significant additional history was elicited. uous with the medial rectus (Fig. 8b). She has Visual acuity and color vision were equal and remained asymptomatic. normal. The left upper lid was ptotic with no Three months later, she was referred for evalu­ levator function evident. The lid was mildly ery­ ation of subcutaneous nodules; biopsy revealed thematous and swollen with a palpable mass dis­ metastatic melanoma. Oncology workup revealed tending the orbital septum. A left hypotropia was disseminated osseous and cutaneous metastasis present and left superior rectus dysfunction was presumably from a cutaneous primary lesion ex­ evident (Fig. 10). Two millimeters of left proptosis cised 10 years previously. Repeat computed to­ were present. The superior conjunctiva was in­ mography at another institution revealed no evi­ flamed. The remainder of the anterior segment and dence for orbital masses or intracranial melanoma. fundus examination was normal. B-scan ultraso­ nography demonstrated enlargement of the left superior rectus. X-rays of the sinuses were normal. Case 4 Computed tomography, obtained prior to referral, demonstrated soft tissue swelling in the anterior A 39-year-old woman was referred for neuro­ and superior orbit. She had not been febrile and ophthalmologic consultation in December 1980, her white blood count was normal. After discon­ complaining of 3 days of pain and diplopia in left tinuing the ampicillin, she was treated with 60 mg upgaze. Medical history was unremarkable except of prednisone daily. In 24 hours, her ptosis and for an episode of iritis in the right eye several years superior rectus paresis had partially resolved as prior to our initial examination. did her subjective symptoms. One week later, she Visual acuity was unimpaired. Upgaze in adduc­ was asymptomatic except for mild residual left tion was restricted, mimicking a right inferior ptosis. Extraocular motility was normal. Steroids oblique paresis (Fig. 9). The trochlear region was were tapered and discontinued over 3 weeks. She tender to palpation and the superomedial quadrant has remained asymptomatic.

70 Journal of Clinical Neuro-ophthalmology Spuur, Hdrtel

Figure 7a, Computed tomogram demonstrating well-circumscribed mass in super­ medial orbit.

Figure 7b, Ring enhancement of orbital mass after injection of intravenous contrast.

Discussion masses with adjacent sinus involvement mimicking The first two cases represent orbital myositis malignant neoplasia of the sinus, invading the orbit confined to the medial rectus, The first patient had through apparent erosion of the medial orbital neither an adjacent sinusitis or an antecedent upper walL No such pseudoerosion was present in our respiratory infection as described previously by patient. Our patient was referred with the dignosis others,:J of orbital cellulitis. Since he was only mildly febrile The second patient demonstrated orbital myos­ (100°F) and had a normal white blood count, we itis of the medial rectus associated with a diffuse suspected inflammatory orbital disease. Computed pansinusitis, mimicking orbital cellulitis, Eshagh­ tomographic evidence of an enlarged medial rectus ian and Anderson4 reported inflammatory orbital confirmed our diagnosis. Both these patients had

March 1983 71 Orbital Myositis

Figure 8a. Folll'w-up computed tl'mogram JemonstrJtlng decre.lSed size llf l'rb,t.,1 mJSS Jnd Ie", of ring enhancement

2) documents total resolution of the inflammatory process in both the orbit and sinuses. Our third case represented what we believe to be a variant of orbital myositis. She presented with a painful ophthalmoplegia thought secondary to orbital myositis and her symptoms responded dra­ matically to systemic corticosteroids within 24 hours. However, her computed tomography (Figs. 7a and 7b) was atypical, demonstrating an enhanc­ ing medial orbital mass that failed to resolve totally on repeat scan 6 weeks later (Figs. 8a and 8b). Evaluation of coron,11 reconstructions obtained during her follow-up scan revealed the mass to be contiguous with the medial rectus (Fig. 8b). These scans are obviously different from those demon­ strating obvious medi.ll rectus enl.:Jrgement. It has been suggested that this picture may represent the lymphocytic variant of idiop.lthic orbital inflam­ mation.-· Shortly after the second computed tomog­ raphy, extensive metastatic melanoma from a cu­ taneous primary was documented. Although we have no histopathologic evidence. we wonder whether this orbital mass may also Figure sb. CllrL)I1JI rt.'I.:nn ... trudipl1 dl'tlHH'l<.,tr.lting n1JSS hl be represent metastatic melanoma with a surrounding 'uperll" ", .II1J "d,Jlt'nt tl' the left nleJi.ll red"'. infl.:Jmmatorv response which responded dramati­ cally to systemic corticosteroids. A discrete metas­ t,lsis to an extraocular muscle from silent small cell the rapid ,md dram,ltic response to systemic corti­ c.lrcinoma has been recently described.1i Although costeroids reported by others. ' -:! They also dem­ mimicking orbital myositis, this patient did not onstrated that medial rectus myositis may occur respond to systemic corticosteroids. However, our with or without adjacent sinus involvement ,md patient's orbital symptoms did not recur after dis­ without ,\ signific.mt antecedent upper respiratt1ry continuing the corticosteroids. A follow-up scan infection. Follow-up computed tomography (c,lse was negative, suggesting an atypical form of orbital

Journ,ll of Clinic.11 Neuro-ophthalmology Spoor, Hartel

Figure 10. Ptosis and impaired elevation. left eye, secondary to orbital myositis. Note swelling and erythema of left upper lid.

involved superior rectus). Computed tomography was nonspecific as obtained on an outmoded unit, demonstrating only swelling of the lid, compatible with a preseptal cellulitis. The diagnosis here was Figure 9. Orbital myositis presenting as a pseudo-Brown's made on clinical grounds-levator and superior syndrome, mimicking a right inferior oblique paresis. rectus dysfunction accompanied by evidence of myositis. We urge clinicians to be suspicious of the inflammation and confirmed by the rapid response diagnosis of orbital myositis if the computed to­ to corticosteroids. High-resolution computed to­ mography picture is atypical in spite of a good mography with appropriate coronal reconstruc­ clinical response to systemic corticosteroids, or if tions might well have documented enlargement of the presumed myositis fails to respond to cortico­ the levator and/or superior rectus. steroids. Orbital myositis represents a distinct clinical Case 4 represented orbital myositis presenting entity that may mimic many disorders of extraocu­ as a pseudo-Brown's syndrome. Again, external lar motility. Evidence for local orbital inflammation signs of inflammation were present over the in­ should obviate against a neurologic etiology for volved area. Computed tomography failed to dem­ these motility disturbances. Orbital myositis must onstrate extraocular muscle enlargement, but we be differentiated from other causes of orbital in­ suspected a trochleitis or myositis based upon flammation with motility disturbances. We believe clinical findings (point tenderness, restriction of this can be done by clinical examination, laboratory motion, and overlying inflammation). A concomi­ data, and computed tomography. tant anterior uveitis has been reported previously The most important entity to differentiate is to accompany orbital inflammation7 and might be orbital cellulitis. In our experience, these patients expected with an anterior site of inflammation. are febrile greater than 102°r, have a polymorpho­ This patient also demonstrated that idiopathic or­ nuclear leukocytosis greater than 15,000, exhibit bital inflammation, if anterior, may be controlled extraocular motility dysfunction, and often have a with topical corticosteroids. concomitant sinusitis or history of trauma. Our Case 5 represented involvement of levator and patients with orbital myositis have been otherwise superior rectus by orbital inflammation in a child. well, essentially afebrile, and have normal white Again, there was evidence for active inflammation blood cell counts. (warmth, erythema, a palpable tender mass over Partially treated orbital cellulitis may be con­ the involved lid, and injection of vessels over the fused with orbital myositis. Case 5 was referred

March 1983 Orbital Myositis

after her orbital swelling failed to respond to in­ Patients with orbital myositis may be extremely travenous and then oral antibiotics. In this situa­ uncomfortable and, in a referral practice, far from tion, without diagnostic, computed tomographic home. Their true clinical picture may be obscured evidence, we suggest discontinuing antibiotics and by previous antibiotic treatment or surgery. Ac­ observation for 24-48 hours. If the clinical status cordingly, our treatment regimen consists of hos­ does not worsen or remains stable, the patient is pitalization for observation and to expedite obain­ treated with systemic corticosteroids expecting a ing computed tomography. Treatment consists of prompt, dramatic response. 50 mg prednisone on admission followed by 80 mg The patient with orbital myositis has an exquis­ daily in four divided doses. A dramatic subjective itely tender orbit to palpation and an obvious and objective improvement is usually evident in motility defect often limited to one or two extra­ the first 12-24 hours. Corticosteroids are rapidly ocular muscles. Vision has been unimpaired in all tapered over 3-4 weeks. Recurrences may be of our cases. treated again with systemic corticosteroids. One We believe the diagnosis of orbital myositis can patient (case 4) is successfully maintained on low­ be made on clinical grounds and confirmed by dose topical steroids after refusing further systemic computed tomographic evidence of an enlarged prednisone. Patients who fail to respond to this extraocular muscle and rapid response to systemic regimen, or have an atypical clinical picture, sub­ corticosteroids. Clinical findings included limita­ sequently undergo either open or fine-needle as­ tion of extraocular motility in the field of action of piration biopsies as their clinical condition dictates. the affected muscle or in the opposite field, coupled In essence, orbital myositis is a clinical diagnosis with evidence of overlying inflammation and ex­ based upon suspicion, signs of extraocular muscle quisite tenderness to palpation. Proptosis is often dysfunction with concomitant overlying inflam­ present, but may be minimal with more anterior mation, and a rapid response to systemic cortico­ lesions. steroids. Computed tomographic evidence for en­ Computed tomography of the orbit may docu­ larged extraocular muscles is helpful; however, if ment markedly enlarged extraocular muscles the computed tomographic picture is atypical, an­ thought to be distinguishable from enlargement other etiology should be considered and a histo­ due to Graves' orbitopathy.8 The tendon is spared pathologic diagnosis obtained. in a muscle enlarged secondry to Graves' orbito­ pathy, whereas both muscle and tendon are en­ References larged (Figs. 3a, 3b, Sa, and 5b) when involved by myositis. Other causes of extraocular muscle en­ 1. Blodi, F. C: Orbital inflammations. Orbit 1: 1-19, largement on computed tomography such as meta­ 1982. static tumors, carotid cavernous fistulae, and 2. Slavin, M. D., and Glaser, J. 5.: Idiopathic orbital trauma should be discernable by history, exami­ myositis. Arch. Ophthalmol. (In press.) 3. Purcell, J., and Taulbee, W. A.: Orbital myositis nation, and failure to respond to corticosteroids. 1. after upper respiratory tract infection. Arch. Oph­ Concomitant sinusitis may also be documented by thalmol. 99: 437, 1981. computed tomography (case 2, Figs. Sa and 5 b). 4. Eshaghian, ]., and Anderson, R. L.: Sinus involve­ 3 We agree with Purcell and Taulbee that orbital ment in inflammatory orbital pseudotumor. Arch. myositis is a distinct clinical entity. However, we Ophthalmol. 99: 627, 1981. find no consistent relationships to antecedent viral 5. Personal communications with 5. Trokel. or streptococcal upper respiratory infections. Ad­ 6. Divine, R. D., and Anderson, R. L.: Metastatic small jacent sinusitis mayor may not be present. When cell carcinoma masquerading as orbital myositis. present (case 2), it responds as dramatically as the Ophthal. Surg. 13: 483, 1981. orbital involvement to systemic corticosteroids. Es­ 7. Mottos, Lippa,S., Jakobiec, F. A., and Smith, M.: haghian and Anderson have demonstrated similar Idiopathic inflammatory pseudotumor in childhood. II. Ophthalmology 88: 565,1981. histopathology in idiopathic orbital and adjacent 8. Trokel, 5., and Hilal, 5.: Recognition and differential sinus inflammation.4 diagnosis of enlarged extraocular muscles in com­ We do not postulate an etiology for orbital puted tomography. Am. /. Ophthalmol. 87: 503, myositis but urge its recognition as a diagnostic 1979. entity by the clinician. Such recognition obviates 9. Jakobiec, F. A., and Jones, I. 5.: Orbital Inflammation the need for biopsying these inflamed orbits with in Diseases of the Orbit. Part 1, Jones and Jakobiec, their higher incidence of postoperative complica­ eds. Harper & Row, Hagerstown, MD, 1979, p. 202. 9 tions. We also recognize that some tumors can 10. Spoor, T. C, Kennerdell, J. 5., Johnson, B. Land respond favorably to corticosteroids for a short Dekker, A.: Orbital fine needle aspiration biopsy time, but rarely as rapidly and completely as orbital with B-scan guidance. Am. /. Ophthalmol. 89: 274, myositis. We ur~e biopsy of patients presenting in 1980. an atYPical fashion, possibly by fine-needle aspi­ Write for reprints to: Thoms C Spoor, MD., 3325 ration under sonographic guidance as described Medical Park Road, Suite 212, Columbia, South Carolina previously. If) 29203.

74 Journal of Clinical Neuro-ophthalmology