ORBITAL MYOSITIS: A CASE REPORT

Author :Dr. Harshdeep Singh Gabba

Co-Author :Dr. Varsha KulkarniProfessor

Bharati Vidyapeeth University Medical College , Pune

IntroductionOrbital Myositis : An inflammation of the extra ocular

muscles with sudden onset Characterized by-a. Orbital inflammationb. Periocular painc. Swelling d. Redness of the eyelidse. Proptosisf. Ptosisg. Ocular motility restrictions

Incidence-7-8% female predominance(2 :1 )

Case Presentation A 12 year old female presented with :Bulging of LE since 5 daysPain over LE more during ocular movementDiplopiaSwelling over LE lower lid

Ophthalmic ExaminationBCVA: RE:-6/6 LE:- 6/186/9 with

+0.75DsHead posture: Face turn towards right.Extra Ocular Movements: LE- restriction

in abduction.

Examination continue LE 4 mm proptosis with fullness of Left.

Periorbital space . Non tender, No bruit or crepitus, Non reducible.

Investigation &TreatmentMRI- Thickened edematous muscle belly of

Medial Rectus

Tab Prednisolone 30mg OD for one month on tapering dose

3 Month Follow UpLE proptosis resolved,ocular motility were

full and free , conjunctival congestion resolved completely, no pain on ocular movement & no diplopia.

Repeated MRI after 3 months-WNL.

DISCUSSIONIdiopathic orbital myositis is classified as a subtype of

nonspecific orbital inflammation1

It commonly occurs between 7-42 years.

Muscles commonly involved are medial rectus (43%), superior rectus (19%), lateral rectus (17%), and rarely oblique’s (5-10%).

DIFFERENTIAL DIAGNOSIS:1. Thyroid eye disease2. Rhabdomyosarcoma 3. Orbital cellulitis4. Orbital psuedotumor2,4 .MRI is helpful in diagnosis.

Associations with bacterial/ viral infection, cysticercosis, sarcoidosis, crohn’s disease & giant cell arteritis has been reported.

In our case patient was 12 years old so diagnosis of rhabdomyosarcoma was also considered.

MRI showed thickening of medial rectus along with involvement of the tendon ruling out thyroid eye disease & rhabdomyosarcoma. 3

Patient responded to systemic steroids with complete regression

TAKE HOME MESSAGEOrbital Myositis is an important entity which

should be differentiated from other ocular myopathies like rhabdomyosarcoma , orbital psuedotumors and thyroid orbitopathy .

MRI is the most useful investigation for diagnosis.

Steroid is the mainstay treatment for Orbital Myositis.

REFERENCES1. Espinoza GM. Orbital Inflammatory Pseudotumors:

Etiology, Differential, Diagnosis, and Management. Curr Rheumatol Rep 2010;12:443-447

2. Benedikt GH Schoser. Ocular myositis; diagnostic assesment, diffrential diagnoses and therapy of rare muscle disease-five new cases and review. Clincal Opthphalmolgy. 2007 Mar;1(1); 37-42

3. Ding ZX, Lip G, Chong V. Idiopathic orbital pseudotumor. Clinical Radiology 2011;66:886-892

4. Cockerham KP, Chan SS. Thyroid Eye Disease. Neurol Clin 2010;28:729-755