Uveitis

Overview  

Uveitis is an inflammation of the uvea, the middle layer of the eye wall, which can manifest suddenly with symptoms such as eye redness, pain, and blurred vision. The inflammation can affect one or both eyes and is observable in individuals of all ages, including children. Although uveitis can result from infections, injuries, or autoimmune disorders, the cause often remains unidentified. 

The anatomy of the eye leaves little room for swelling, making any inflammation potentially harmful as it can alter the eye’s shape and impair vision. This condition can be localized to specific areas of the eye or involve multiple regions, leading to varying degrees of pain and visual disruption. 

Prompt diagnosis and treatment of uveitis are crucial to prevent serious outcomes, including permanent vision loss or blindness. Early medical intervention is essential to manage symptoms effectively and preserve eyesight. 

Symptoms  

Uveitis is an inflammatory condition affecting the uvea, the middle layer of the eye’s tissue, which includes the iris, the ciliary body, and the choroid. Below is a detailed breakdown of the symptoms, characteristics, and anatomy relevant to uveitis: 

Symptoms of uveitis 

• Eye redness: The eye may appear red and irritated. 
• Eye pain: Discomfort can range from mild to severe. 
• Light sensitivity: There is often increased sensitivity to light. 

• Blurred vision: Vision may become blurry and unclear. 
• Floaters: Dark, floating spots may appear in the field of vision. 
• Decreased vision: There may be a noticeable reduction in visual acuity. 

These symptoms can develop suddenly and worsen quickly, or they might emerge gradually. Uveitis can affect one or both eyes. In some cases, symptoms may not be noticeable, and uveitis is only detected during a routine eye exam. 

Anatomy of the uvea 

• Iris: The colored part of the eye, visible when looking in the mirror. 
• Ciliary body: Located behind the iris, this structure controls the focusing shape of the eye’s lens. 
• Choroid: A layer of blood vessels situated between the retina and the sclera that provides oxygen and nutrients to the eye. 

The eye’s internal back is lined by the retina, akin to wallpaper, and filled with a gel–like substance called the vitreous. This anatomy plays a critical role in the symptoms and management of uveitis. 

Classification of uveitis 

Uveitis can be classified based on the specific area affected: 

• Anterior uveitis: This most common form impacts the front inside part of the eye, specifically between the cornea and the iris, as well as the ciliary body. It is also referred to as iritis. 
• Intermediate uveitis: This type targets the retina, blood vessels near the lens (pars plana), and the vitreous, the gel–like substance in the center of the eye. 
• Posterior uveitis: This affects the inner layer at the back of the eye, involving either the retina or the choroid. 
• Panuveitis: This severe form occurs when all layers of the uvea are inflamed, affecting the eye from front to back. 

If you experience symptoms that suggest uveitis, consult your doctor promptly. They may refer you to an ophthalmologist. For severe eye pain or sudden vision issues, seek immediate medical attention. 

Causes  

In about half of all uveitis cases, the underlying cause remains unidentified, and the condition is often considered an autoimmune response that primarily affects the eyes. When a specific cause is identified, it could be one of several factors:  

• Ankylosing spondylitis, a type of inflammatory disease that may cause bones in the spine to fuse together, leading to significant back pain. Uveitis is a common complication associated with this condition.  
• Other autoimmune or inflammatory disorders that impact various parts of the body, including sarcoidosis, systemic lupus erythematosus, or Crohn’s disease.  
• Infections such as tuberculosis, syphilis, herpes zoster, toxoplasmosis, or cat scratch disease.  
• Side effects from certain medications.  
• Eye injuries or surgical procedures.  
• In very rare cases, an eye cancer such as lymphoma.  

Risk factors  

Individuals with alterations in specific genes may have an increased risk of developing uveitis. Additionally, cigarette smoking has been linked to more challenging–to–control uveitis.