Pregnant patient presents with eye pain

A 24-year-old Caucasian female was referred from urgent care with a chief complaint of pain in and around the right eye that had begun 4 days prior. She had also noticed pain on eye movement. The patient’s pain had intensified the night before the examination, with feelings of a pressure sensation inside the eye. This prompted a visit to urgent care the following day, with the patient ranking the pressure sensation as a seven out of 10 on the pain scale. She denied any prior occurrences.

The patient reported no recent trauma, diplopia or foreign body sensation. She felt that her vision had not been affected. She also reported a headache in the frontal brow region above the right eye.

Her significant medical history included obesity (BMI = 42 kg/m2). Her blood pressure as measured in urgent care was 118/76 mm Hg. The patient was 16 weeks pregnant at the time of the examination. Her medications included daily multivitamins and acetaminophen as needed for pain. The patient reported no medication allergies. She denied a history of smoking. Her ocular history was unremarkable.

Uncorrected Snellen visual acuity tested 20/30 OD and 20/20-2 OS; the right eye improved to 20/20-1 with pinhole acuity. No refraction was performed at this visit. Eye movements were full, without restriction. There was pain on horizontal and superior eye movement in the right eye. The pain was more intense when the patient tried to look up. Pupils were equal, round and reactive to light with no relative afferent pupillary defect. Confrontation fields were full to finger count in both eyes.

The patient correctly identified 14 out of 14 Ishihara color plates with each eye. She saw seven out of nine test circles when tested for depth perception using the Wirt stereo test. Measurements with Hertel exophthalmometry were 22 mm OD and 20 mm OS. Palpebral fissures were 14 mm OD and 16 mm OS. Levator function testing measured 17 mm OD and 18 mm OS.

With retropulsion, both globes showed equal anteroposterior movement with no resistance. The patient reported mild pain in the right globe with palpation. Palpation of the frontal and maxillary sinuses elicited no pain. Transillumination of the frontal and maxillary sinuses was equal, indicating no evidence of sinus involvement.

Anterior segment examination with slit lamp was unremarkable. Intraocular pressure was 14 mm Hg in each eye. A dilated fundus examination revealed no disc edema or disc atrophy. The maculas were unremarkable. The peripheral fundus was also unremarkable, and the vitreous was of normal consistency and clarity in each eye.

Magnetic resonance imaging (MRI) of the face, neck, and orbit was ordered for the patient without contrast due to the patient being pregnant.

What’s your diagnosis?

This patient was diagnosed with ocular myositis of the medial rectus muscle in the right eye.

Differential diagnoses include but are not limited to: thyroid-related orbitopathy, posterior scleritis, infectious orbital disease, orbital mass and Tolosa-Hunt syndrome.

Thyroid-related orbitopathy

Thyroid-related orbitopathy (TRO) is the most common cause of extraocular muscle dysfunction. Peak onset occurs in adults between 30 and 50 years old and it affects women two to four times more frequently than men (Costa et al.). The findings of TRO can be similar to that of ocular myositis, but the latter presents in a more acute, severe onset, with more immediate response to corticosteroid treatment.

TRO is often characterized by bilateral involvement of the muscles, although asymmetric or unilateral presentations can occur. Lid lag and lid retraction in downgaze are also characteristic findings of TRO that are not likely to be seen in ocular myositis. In severe cases with compressive optic neuropathy, vision impairment can occur.

One of the primary factors that differentiates ocular myositis and TRO is the involvement of the vertical rectus muscle in TRO. In ocular myositis, a CT or MRI scan would show enlargement of the entire involved muscle, including the tendon. Visualizing the thickening of the tendinous insertions onto the globe would help differentiate against it being thyroid orbitopathy, as thyroid-related issues classically do not involve the associated tendons. Additionally, enlargement of the orbital fat compartment is commonly observed in TRO. The T2 axial MRI shows that our patient’s medial rectus muscle exhibits enhancement and enlargement of the muscle belly and the tendons. To definitively rule out a TRO diagnosis, the patient should have a complete thyroid panel evaluation.

Posterior scleritis

Posterior scleritis also can present with moderate to severe eye pain that often wakes a patient from sleep. It can be exacerbated by extraocular motility or touch. Proptosis or other orbital signs may be present. Vision can also be variably affected, from minimal to significant loss. About half of the patients with posterior scleritis may present with elevated IOP. Other signs include optic disc swelling, macular edema, choroidal folds, retinal striae, exudative retinal detachment or rapid-onset hyperopia (Bagheri et al.). Posterior scleritis was ruled out in this case because our patient did not have the above-mentioned signs. Posterior scleritis also classically presents with increased choroidal thickness on imaging, which was not seen in our case.

Infectious orbital disease

Infectious orbital disease should also be ruled out. These patients present with red eye, ocular pain not related to eye movements, decreased or blurred vision, or proptosis. Eyelid warmth and tenderness is common, as well as sinus-related pressure or congestion. Optic disc edema, purulent discharge and fever may also be present. It is important to ask about any recent trauma, skin lesions or dental work that could have introduced an infectious agent. Recent upper respiratory illness or sinus infection is a common cause; a CT scan will help evaluate for possible abscess and will commonly show adjacent sinus involvement. An MRI can demonstrate diffuse inflammation and enhancement of orbital or periorbital structures while also evaluating cavernous sinus involvement, abscesses or involvement of other intracranial regions. Fever or elevated white blood cell count are also suspicious for an infectious cause. None of these distinctive characteristics was found in our patient.

Orbital mass

Any orbital mass may result with pain, proptosis and limitation of eye movement. Diplopia, decreased vision, orbital inflammation or mass on palpation may be found. The condition may occasionally be asymptomatic. In our case, an orbital mass was ruled out with imaging.

Tolosa-Hunt syndrome

Tolosa-Hunt syndrome is a rare inflammatory condition that consists of painful ophthalmoplegia and is included in the spectrum of idiopathic orbital inflammatory syndrome/orbital pseudotumor. Pain can be periorbital or hemi-cranial. Ipsilateral motor nerve palsies, oculosympathetic paralysis and/or sensory loss of the trigeminal nerve ophthalmic and maxillary divisions can occur. Much of the work-up is the same as that of ocular myositis. It will also likely respond to oral corticosteroid treatment. Imaging is necessary to help differentiate from ocular myositis, as the inflammatory changes in Tolosa-Hunt syndrome would be seen in the cavernous sinus, superior orbital fissure and/or orbital apex (Schoser).

Evaluation

It is important to thoroughly examine the patient for external appearance and ocular alignment. Visual acuities, pupil function, extraocular motilities and exophthalmometry are critical components to assess. Slit lamp biomicroscopy, IOP measurements and a dilated fundus examination are also essential. Idiopathic ocular myositis is a diagnosis of exclusion and can only be made after extensive evaluation to rule out occurrence secondary to systemic disease or infection.

In patients who present with clinical findings it is important to first look for signs or symptoms of systemic disease such as Lyme disease, herpes zoster, Whipple disease, and upper or lower respiratory diseases. These systemic diseases have been found to have a high correlation with ocular myositis. It is important to obtain a complete history and ask about more specific symptoms that could help refine your assessment.

Diagnostic evaluation consists of complete blood count (CBC), erythrocyte sedimentation rate (ESR), C-reactive protein and thyroid function tests. Additional laboratory tests designed to detect specific diseases should be ordered as indicated by history or findings, such as assessment of autoimmune antibodies or a systemic lupus workup.

Imaging could consist of a CT scan, ultrasound and/or MRI depending on the available resources; however, if the patient is pregnant, CT is contraindicated, and MRI without contrast is preferred. An MRI with and without contrast and with fat suppression is preferred in patients who are not pregnant, as this best evaluates soft tissue. Ultrasonography might give evidence of edema in the muscle by showing thickening of the tendinous insertions. It could also demonstrate decreased reflectivity of the muscles affected by orbital myositis. An ultrasound or CT scan could rule out or demonstrate evidence of coexisting posterior scleritis. MRI provides the best imaging for diagnosis because it is more fluid-sensitive, resulting in edema being more readily identified.

Patients with an atypical presentation or lack of response to treatment may require biopsy and tissue diagnosis. Fine-needle aspiration biopsy can be a helpful diagnostic technique, particularly if imaging results are confusing or inconclusive. Biopsy should be performed with caution in suspected acute orbital myositis because it can potentially increase the underlying inflammation. Due to invasiveness of this technique, orbital biopsy should be utilized in treatment-resistant cases to rule out the presence of neoplastic tissue or lymphoproliferative processes.

Description/etiology

Ocular myositis is an inflammatory disorder affecting one or more of the extraocular muscles. It is a subgroup of idiopathic orbital inflammatory syndrome, also known as orbital pseudotumor, accounting for approximately 8% of all idiopathic orbital inflammation (Fraser et al.). Ocular myositis may be acute, subacute or chronic/recurrent. Males, patients with proptosis or those given inadequate treatment are more likely to develop recurring myositis.

The underlying inflammation is thought to be caused by an immune-mediated mechanism, although the exact pathophysiology is unknown. Although most cases are ruled idiopathic in nature, this could be due to lack of subsequent biopsies to determine the possible source. There has been some correlation with infectious causes, both bacterial and viral (Fraser et al., Schoser). Ocular myositis has also been associated with systemic inflammatory diseases such as: systemic lupus erythematosus, Crohn’s disease, sarcoidosis and antineutrophil cytoplasmic antibody-associated vasculitis. It is often characterized by its responsiveness to corticosteroid treatment, which is considered both therapeutic and diagnostic in nature.

This disease affects women twice as often as men. It often occurs in the third and fourth decades of life but may be diagnosed throughout the lifespan. Unilateral involvement is reported in 70% to 95% of adult cases (Fraser et al). While ocular myositis is less common in children, when it does occur they are more likely to have bilateral ocular involvement and changes in their constitution such as headache, lethargy or fever. Patients commonly present with orbital pain and diplopia. Diplopia may present in more than half of patients, along with restricted extraocular movements (Fraser et al., Costa et al.). Acute, explosive pain occurs in 65% of patients (Bagheri et al.). Eighty percent of patients report that the pain is exacerbated with any eye movement (Fraser et al.). The most common ocular muscles that are affected are the horizontal recti.

Typical physical exam findings include edema of the eyelids and conjunctiva. Conjunctival hyperemia can range from minimal injection at the site of muscle insertion to extensive chemosis. Proptosis is usually minimal if present, and ptosis may also variably be present. Visual acuity of these patients is often unaffected (Costa et al.). A recent study suggested that diagnostic criteria for myositis includes: acute orbital pain exacerbated by movement, enlargement of one or more extraocular muscles with respect to the other orbital structures on CT scan, absence of clinical or orbital thyroid dysfunction, absence of anterior uveitis or scleritis, no reduction of visual acuity and response to immunomodulatory treatment such as corticosteroids.

Treatment

Our patient’s obstetrician was contacted, and the patient was started on 80 mg of oral prednisone daily with a slow month-long taper. At her 1-month follow-up visit she reported that the orbital pain had completely resolved and had not recurred since stopping the prednisone. She had no more pain on eye movement. Uncorrected visual acuities were 20/40+1 OD and 20/20 OS. Pinhole acuity was 20/25 OD. Hertel exophthalmometry measured 21 mm OD and 20 mm OS. There were no other pertinent ocular or medical findings. The patient was instructed to return to the eye clinic if symptoms recurred and to see her optometrist for an updated refraction.

Classic management of ocular myositis is oral corticosteroids. Corticosteroid treatment often results in a rapid improvement in symptoms, which can be both therapeutic and diagnostic in nature. More than 75% of patients show dramatic improvement in the first 24 to 48 hours of treatment (Chaudhry et al.). A dose of 1 mg/kg of body weight per day of oral corticosteroids is considered an adequate starting dose (Myers et al.). Slow steroid tapering has been shown to vastly improve symptoms, with a typical tapering reduction of 10 mg every 3 to 7 days (Avni-Zauberman et al.).

It has been found that if a large enough dose of steroid is not given in the initial treatment, the disease tends to become recurrent or chronic in nature, with recurrence observed in up to 75% of patients (Costa et al.). If the patient has a recurrent or chronic form of the disease, then repeat courses of steroids, and maintenance dosing may be required. All patients should be warned about corticosteroid-induced side effects and instructed to follow up with their primary care provider to monitor blood sugar and electrolytes.

If prompt relief within the first month is not found with oral corticosteroid use alone, it is recommended that other immunosuppressive medications be added. Nonsteroidal anti-inflammatory drugs in conjunction with low-dose oral steroids have been shown to improve symptoms (Costa et al.). Other forms of treatment include low-dose radiotherapy, which has shown improvement of overall ocular inflammation along with a decrease in long-term steroid use (Fraser et al.). Biologics have been reported successful for chronic or recurrent ocular myositis. Immunosuppressants have been used with variable results (Montagnese et al.). These additional or alternative treatments may be required if a patient has an intolerance to steroids or has been unresponsive to treatment with systemic corticosteroids. These alternative methods should only be used once orbital biopsy, if feasible, has been performed and other causes have been excluded.

The initial therapy for orbital inflammation during pregnancy is not different from that which would be given to a patient who was not pregnant. Maximal oral corticosteroid therapy should be prescribed for 1 to 2 weeks followed with a slow taper (Jakobiec et al.) Fetal injury is more closely associated with the severity of any associated systemic disease than the use of carefully prescribed oral corticosteroids. It has been found that corticosteroids have a very low to minimal teratogenic potential (Jakobiec et al.). Over-the-counter nonsteroidal anti-inflammatory agents may be used before the third trimester of pregnancy. Radiotherapy, if necessary, must be cautiously utilized in pregnant women.

References:

• Avni-Zauberman N, et al. Br J Ophthalmol. 2012;doi:10.1136/bjo.2010.191866.
• Bagheri N, Wajda BN. The Wills Eye Manual: Office and Emergency Room Diagnosis and Treatment of Eye Disease. 7th ed. Philadelphia: Wolters Kluwer; 2017;117-119, 148-168.
• Char DH, et al. Ophthalmology. 1993;doi:10.1016/S0161-6420(93)31414-4.
• Chaudhry IA, et al. Mid E African J Ophthalmol. 2008;doi:10.4103/0974-9233.53370.
• Costa RMS, et al. Curr Allergy Asthma Rep. 2009;doi:10.1007/s11882-009-0045-y.
• Fraser CL, et al. Curr Allergy Asthma Rep. 2013;doi:10.1007/s11882-012-0319-7.
• Jakobiec FA, et al. Am J Ophthalmol. 2016;doi:10.1016/j.ajo.2016.03.029.
• Montagnese F, et al. J Neurol. 2016;doi:10.1007/s00415-015-7926-x.
• Myers LA, et al. Idiopathic orbital myositis: A treatment algorithm. EyeRounds.org. http://EyeRounds.org/cases/234-Idiopathic-Orbital-Myositis.htm. Posted May 27, 2016. Accessed April 13, 2018.
• Schoser BG. Clin Ophthalmol. 2007;1(1):37-42.
• Wieseler KM, et al. Radiographics. 2010;doi:10.1148/rg.305105034.

For more information:

Emmalee A. Toldo, BS, BA, of Side Lake, Minn., is a fourth-year optometry student at Pacific University in Forest Grove, Ore. She can be reached at: e.toldo@pacificu.edu.

Sebastian P. Baker, APRN, CNP, of Syracuse, N.Y., is in the nurse practitioner/physician assistant emergency medicine fellowship at Mayo Clinic in Rochester, Minn. He can be reached at: baker.sebastian@mayo.edu.

Leonid Skorin Jr., OD, DO, MS, FAAO, FAOCO, practices at the Mayo Clinic Health System in Albert Lea, Minn., and is a member of the Primary Care Optometry News Editorial Board. He can be reached at: skorin.leonid@mayo.edu.

Edited by Leo P. Semes, OD, FAAO, a Primary Care Optometry News Editorial Board member. He can be reached at: leopsemes@gmail.com.