Myositis is a rare inflammatory disease that primarily affects the muscles, causing weakness, pain, and fatigue. While it commonly impacts skeletal muscles, this condition can also affect eye movement and surrounding muscles. When myositis involves the ocular system, it can lead to a range of symptoms that impact both vision and eye function.
Types of Myositis Affecting the Eyes
Myositis can manifest in various forms, with some having a more direct impact on the eyes. Ocular myositis, also known as orbital myositis, specifically targets the extraocular muscles that control eye movement. This localized inflammation can affect a single eye or, less commonly, both eyes sequentially.
Ocular myositis is considered a rare inflammatory disorder within the broader category of idiopathic orbital inflammatory syndrome. It is characterized by inflammation and swelling of these eye muscles. While often idiopathic (without a known cause), it can sometimes be associated with systemic autoimmune diseases.
Systemic forms of myositis, such as dermatomyositis and polymyositis, generally affect muscles throughout the body, including the shoulders, hips, and thighs. Although less common, these broader inflammatory conditions can sometimes have secondary effects on the eyes due to widespread inflammation. Ocular involvement in systemic myositis is less direct and frequent compared to ocular myositis.
Recognizing Eye Symptoms
Myositis affecting the eyes can produce several distinct symptoms related to muscle inflammation and impaired eye function:
Double vision (diplopia) occurs when inflamed extraocular muscles disrupt coordinated movement, causing eyes to not align properly. This results in seeing two images.
Blurred vision may develop as muscle inflammation interferes with the eye’s ability to focus.
Eye pain is common and can worsen with eye movement. It is often described as a dull retroorbital discomfort.
Drooping of the eyelid (ptosis) can occur if eyelid-controlling muscles are affected.
Limited eye movement makes it difficult to move the eye in specific directions, arising from inflammation within the muscles.
Redness and swelling around the eye or eyelid are visible signs of inflammation.
In more severe cases, inflammation can cause the eye to bulge forward (proptosis) when swelling within orbital tissues pushes the eyeball outward.
Diagnosing Myositis-Related Eye Conditions
Diagnosing myositis that affects the eyes involves a thorough evaluation by healthcare professionals, often including an ophthalmologist and a rheumatologist. The process begins with a comprehensive eye examination to assess eye movement, visual acuity, and overall eye structure health. This helps identify any restrictions or abnormalities.
Imaging studies are a cornerstone of diagnosis, with Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scans of the orbits being useful. These scans visualize inflamed eye muscles, showing swelling and enhancement. MRI is considered the most sensitive imaging modality for detecting these changes.
Blood tests also support the diagnosis, especially when systemic myositis is suspected. These tests may include inflammatory markers like C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), which indicate general inflammation. Autoantibody panels detect specific antibodies often present in autoimmune conditions.
A muscle biopsy, while less common for ocular myositis, might be considered in some cases to confirm inflammation and rule out other conditions. This involves taking a small sample of muscle tissue for microscopic examination. For ocular myositis, diagnosis is often based on clinical findings and imaging results, with biopsy reserved for atypical or unclear cases.
Management and Treatment
The primary goals of managing myositis-related eye symptoms are to reduce inflammation, alleviate discomfort, and preserve eye function and vision. Treatment strategies aim to suppress the immune response that drives inflammation in the muscles.
Corticosteroids are the first-line treatment for ocular myositis due to their anti-inflammatory effects. These medications can be administered orally, intravenously, or through local injections directly into the affected area. Patients often experience prompt improvement in symptoms within days to weeks after starting corticosteroid therapy.
For severe, recurrent, or non-responsive cases, other immunosuppressive medications may be used. These include drugs like azathioprine, methotrexate, or mycophenolate mofetil, which suppress the immune system to control inflammation. These medications can help reduce reliance on corticosteroids and manage long-term disease activity.
Supportive care measures also play a role, such as pain relief for eye discomfort. Long-term monitoring is important, involving ongoing follow-up appointments with ophthalmologists and rheumatologists. This allows for close observation of disease progression, management of potential relapses, and adjustment of treatment plans to maintain eye health and overall well-being.