GENERAL KNOWLEDGE

A BEGINNER’S GUIDE TO UVEITIS

May 16, 2023

Uveitis is a medical condition characterized by inflammation of the uvea, the middle layer of the eye. The uvea consists of the iris, ciliary body, and choroid, which are responsible for supplying blood to the retina and controlling the size of the pupil.

Uveitis can affect one or both eyes and may be classified based on the part of the uvea that is primarily affected. The three main types of uveitis are:

  1. Anterior uveitis: This type affects the front part of the uvea, primarily involving the iris and the adjacent tissues. It is the most common form of uveitis and is often referred to as iritis or anterior chamber uveitis.
  2. Intermediate uveitis: This type affects the middle part of the uvea, primarily involving the ciliary body. It is also known as pars planitis and can be associated with other systemic conditions.
  3. Posterior uveitis: This type affects the back part of the uvea, primarily involving the choroid. It is often referred to as choroiditis and can also involve the retina. Posterior uveitis can be further classified as focal, multifocal, or diffuse depending on the pattern of inflammation.

Uveitis can have various causes, including autoimmune disorders, infections, trauma, and underlying systemic diseases. Symptoms of uveitis may include eye redness, pain, blurred vision, sensitivity to light (photophobia), and floaters. If left untreated, uveitis can lead to complications such as cataracts, glaucoma, and permanent vision loss.

Diagnosis of uveitis typically involves a comprehensive eye examination, including visual acuity testing, slit-lamp examination, and ophthalmoscopy. Additional tests such as blood tests, imaging studies, and sometimes a sample of the aqueous humor (fluid in the front of the eye) may be performed to determine the underlying cause.

Treatment of uveitis aims to reduce inflammation, alleviate symptoms, and prevent complications. It often involves the use of topical or systemic corticosteroids to control the inflammation. Depending on the cause and severity of the uveitis, other medications such as immunosuppressants or biologic agents may be prescribed. Regular follow-up visits with an ophthalmologist are essential to monitor the condition and adjust the treatment as needed.

 

Uveitis Classification by Location

Uveitis is classified based on its anatomical location within the eye. The most commonly used classification system for uveitis is the Standardization of Uveitis Nomenclature (SUN) Working Group classification. According to this classification, uveitis is categorized into four main anatomical locations:

  1. Anterior Uveitis: This type of uveitis affects the anterior part of the uvea, which includes the iris and ciliary body. It is further divided into two subtypes: a. Acute Anterior Uveitis (also known as iritis): Inflammation primarily involves the iris and anterior chamber. b. Anterior Uveitis with Hypopyon: This subtype involves the presence of pus (hypopyon) in the anterior chamber, along with inflammation of the iris.
  2. Intermediate Uveitis: This type of uveitis affects the intermediate part of the uvea, specifically the vitreous humor and peripheral retina. It is characterized by the presence of inflammatory cells in the vitreous gel.
  3. Posterior Uveitis: This type of uveitis affects the posterior part of the uvea, which includes the choroid and retina. It can be further categorized into several subtypes: a. Focal Choroiditis: Inflammation primarily involves a small area of the choroid. b. Multifocal Choroiditis: Multiple discrete areas of choroid inflammation are present. c. Diffuse Choroiditis: Widespread inflammation affecting a larger area of the choroid. d. Chorioretinitis: Inflammation involves both the choroid and the retina.
  4. Panuveitis: This type of uveitis involves inflammation in all parts of the uvea, including the anterior chamber, vitreous humor, and retina.

It’s important to note that uveitis classification systems may vary slightly, and additional details, such as the presence of associated systemic conditions or etiology, may also be considered in some classifications. A comprehensive evaluation by an ophthalmologist is necessary for an accurate diagnosis and appropriate management of uveitis.

 

Anterior & Posterior Uveitis

Anterior uveitis and posterior uveitis are two distinct forms of uveitis, which is an inflammation of the uvea, the middle layer of the eye. The uvea consists of the iris, ciliary body, and choroid. Here’s a breakdown of the clinical presentations for both types:

  1. Anterior Uveitis:
    • Anterior uveitis, also known as iritis, affects the front part of the uvea, primarily involving the iris.
    • Symptoms typically develop rapidly and may include eye redness, eye pain or discomfort (often described as a dull ache), sensitivity to light (photophobia), blurred vision, and increased tear production.
    • The affected eye may appear red, and there may be a small pupil (miosis) due to iris inflammation.
    • In severe cases, there may be visible inflammation cells or proteinaceous debris floating in the anterior chamber of the eye, which can be observed during an eye examination.
    • Anterior uveitis can occur as an isolated episode or be associated with underlying systemic conditions, such as autoimmune diseases (e.g., ankylosing spondylitis, juvenile idiopathic arthritis), infection, or trauma.
  2. Posterior Uveitis:
    • Posterior uveitis primarily affects the back part of the uvea, involving the choroid and/or retina.
    • Symptoms may be more subtle and develop gradually. They can include decreased or blurred vision, floaters (spots or threads that appear to float in the visual field), and, occasionally, flashes of light.
    • Unlike anterior uveitis, posterior uveitis may not cause significant eye redness or pain unless there are associated complications.
    • An ophthalmologist may observe characteristic findings during an eye examination, such as inflammation in the vitreous gel (vitreous cells) or on the retina.
    • Posterior uveitis is often associated with underlying conditions such as infectious diseases (e.g., toxoplasmosis, cytomegalovirus), inflammatory disorders (e.g., Behçet’s disease, sarcoidosis), or autoimmune conditions.

It’s important to note that uveitis can vary in severity, duration, and recurrence patterns. Prompt evaluation and appropriate management by an ophthalmologist are crucial for accurate diagnosis and effective treatment.

 

Anterior Uveitis Signs

Anterior uveitis is the inflammation of the middle layer of the eye, known as the uvea, particularly in the front part of the eye.

Here are some common signs and symptoms of anterior uveitis:

  1. Eye redness: The affected eye may appear red or bloodshot.
  2. Eye pain: Anterior uveitis can cause eye discomfort or pain, which may be mild to severe.
  3. Photophobia: Individuals with anterior uveitis often experience sensitivity to light, making their eyes more sensitive to bright lights.
  4. Blurred vision: Vision may become blurred or cloudy in the affected eye.
  5. Eye floaters: Small, dark spots or floaters may appear in the field of vision.
  6. Irregular pupil: The pupil may become smaller or irregularly shaped due to inflammation.
  7. Eye discharge: Some people may experience discharge or tearing from the affected eye.

It’s important to note that these signs and symptoms can vary from person to person, and not all of them may be present in every case of anterior uveitis. If you suspect you may have anterior uveitis or are experiencing any concerning eye symptoms, it’s crucial to consult with an eye care professional for an accurate diagnosis and appropriate treatment.

 

B27 Uveitis Overview

HLA-B27 related uveitis, also known as HLA-B27 associated anterior uveitis or simply B27 uveitis, is a form of uveitis that is strongly associated with the presence of the human leukocyte antigen B27 (HLA-B27) genetic marker. Uveitis is an inflammatory condition affecting the uvea, which is the middle layer of the eye.

HLA-B27 is a gene that codes for a protein found on the surface of white blood cells. While the exact cause of HLA-B27 related uveitis is not fully understood, it is believed that the interaction between the HLA-B27 protein and certain triggers, such as infections or autoimmunity, can lead to an immune response that causes inflammation in the eye.

Here are some key points about HLA-B27 related uveitis:

  1. Association with HLA-B27: The presence of the HLA-B27 genetic marker increases the risk of developing uveitis. However, it’s important to note that not all individuals with HLA-B27 will develop uveitis, and uveitis can also occur in individuals without this marker.
  2. Anterior uveitis: HLA-B27 related uveitis primarily affects the anterior segment of the eye, specifically the iris and the ciliary body. It is the most common form of uveitis associated with HLA-B27.
  3. Symptoms: Symptoms of uveitis can include eye redness, eye pain, light sensitivity (photophobia), blurred vision, and increased floaters. These symptoms may come on suddenly and may affect one or both eyes.
  4. Recurrent episodes: HLA-B27 related uveitis often follows a recurrent course, with episodes of inflammation that can last from a few days to several weeks. There may be periods of remission between episodes.
  5. Associated conditions: HLA-B27 related uveitis is more commonly seen in individuals with certain conditions that are also associated with HLA-B27, such as ankylosing spondylitis, reactive arthritis, psoriatic arthritis, and inflammatory bowel disease (such as Crohn’s disease or ulcerative colitis).
  6. Treatment: The treatment of HLA-B27 related uveitis typically involves the use of corticosteroid eye drops to reduce inflammation. In more severe or recurrent cases, additional medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), immunosuppressive drugs, or biologic agents may be prescribed.

If you suspect you have uveitis or are experiencing any symptoms related to your eyes, it’s important to consult an ophthalmologist or an eye care professional for a proper diagnosis and appropriate treatment.

 

JIA Uveitis Overview

Juvenile idiopathic arthritis (JIA) is a chronic autoimmune disorder that primarily affects children and adolescents. One of the potential complications of JIA is uveitis, which refers to inflammation of the uvea, the middle layer of the eye.

Uveitis can occur in various forms and can affect one or both eyes. When it is associated with JIA, it is known as JIA-related uveitis or juvenile idiopathic arthritis-associated uveitis. It is the most common extra-articular manifestation of JIA.

Here are some key points about JIA-related uveitis:

  1. Prevalence: Approximately 10-30% of children with JIA develop uveitis. The risk is higher in certain subtypes of JIA, such as oligoarticular and extended oligoarticular JIA.
  2. Symptoms: JIA-related uveitis can be asymptomatic in the early stages, making regular eye examinations crucial for early detection. When symptoms are present, they may include eye redness, pain, light sensitivity, blurred vision, and floaters.
  3. Diagnosis: Ophthalmologists typically diagnose uveitis through a comprehensive eye examination, including visual acuity testing, slit-lamp examination, and dilated fundus examination. A diagnosis of JIA-related uveitis is made when uveitis occurs in conjunction with JIA.
  4. Treatment: The goal of treatment is to control inflammation, preserve vision, and prevent complications. Treatment options may include topical or systemic corticosteroids, immunosuppressive medications (such as methotrexate), biologic agents (such as tumor necrosis factor inhibitors), and local intraocular therapies.
  5. Monitoring: Regular eye examinations are essential to monitor disease activity and detect any complications. The frequency of visits depends on the severity of uveitis and the treatment plan.
  6. Prognosis: With early diagnosis and appropriate treatment, the prognosis for JIA-related uveitis has improved. However, some individuals may experience chronic or recurrent uveitis, which can lead to complications like cataracts, glaucoma, band keratopathy, and vision loss.

It is important for children with JIA to receive regular eye examinations, even if they do not have any symptoms of uveitis, as early detection and treatment can help prevent long-term complications and preserve vision. A multidisciplinary approach involving rheumatologists and ophthalmologists is often required to manage JIA-related uveitis effectively.

 

Toxo Uveitis Overview

Toxoplasma uveitis, also known as ocular toxoplasmosis, is an inflammation of the uvea, which is the middle layer of the eye. It is caused by the parasite Toxoplasma gondii. This parasite can infect humans and animals, and it is estimated that about one-third of the world’s population has been exposed to it.

Toxoplasma uveitis typically occurs when the parasite becomes active after a previous infection. The parasite can remain dormant in the body for many years, and certain factors, such as a weakened immune system, can trigger its reactivation. The infection usually enters the eye through the bloodstream or by direct contact with infected material.

Symptoms of toxoplasma uveitis can vary but commonly include blurred vision, eye redness, eye pain, light sensitivity, and floaters (spots or cobwebs in the visual field). If left untreated, it can lead to severe vision loss or other complications.

Diagnosis of toxoplasma uveitis is based on a combination of clinical signs, patient history, and laboratory tests. An ophthalmologist may perform a comprehensive eye examination, including a visual acuity test, slit-lamp examination, and fundus examination. Laboratory tests, such as a blood test to detect antibodies against Toxoplasma gondii or a polymerase chain reaction (PCR) test, may be performed to confirm the diagnosis.

Treatment for toxoplasma uveitis usually involves a combination of medications to control the inflammation and kill the parasite. Antibiotics, such as pyrimethamine and sulfadiazine, are commonly used. Corticosteroids may also be prescribed to reduce inflammation in the eye. In some cases, anti-inflammatory injections or surgeries may be necessary.

It is important to note that toxoplasma uveitis can have long-term effects on vision, and even with treatment, some degree of visual impairment may persist. Therefore, early detection, prompt treatment, and regular follow-up with an ophthalmologist are crucial for managing this condition effectively.

Uveitis Treatment Overview

The treatment of anterior and posterior uveitis typically involves a combination of medication and sometimes additional therapies. Uveitis refers to the inflammation of the uvea, which is the middle layer of the eye.

  1. Medications:
    • Corticosteroids: These medications help reduce inflammation and are often prescribed as eye drops (topical) for anterior uveitis. In more severe cases, oral or injectable corticosteroids may be used. Long-term use of corticosteroids may have side effects, so the dosage and duration of treatment should be carefully monitored.
    • Immunosuppressive drugs: If corticosteroids alone are insufficient or need to be tapered off, immunosuppressive drugs may be prescribed. These medications, such as methotrexate, azathioprine, or mycophenolate mofetil, work by suppressing the immune system to reduce inflammation.
    • Biologic agents: In cases of refractory uveitis or when other medications are ineffective, biologic agents may be used. Examples include tumor necrosis factor-alpha (TNF-alpha) inhibitors like infliximab or adalimumab, or interleukin-6 (IL-6) inhibitors like tocilizumab. These medications target specific molecules involved in the immune response.
  2. Additional Therapies:
    • Cycloplegic agents: These eye drops are used to dilate the pupil and relieve pain associated with uveitis. They also help prevent complications such as synechiae (adhesions between the iris and lens).
    • Intraocular injections: In severe cases, injections of corticosteroids or other anti-inflammatory medications directly into the eye (intravitreal injections) may be administered.
    • Systemic evaluation: Uveitis can sometimes be associated with underlying systemic conditions, such as autoimmune disorders or infections. Therefore, a thorough evaluation may be necessary to identify and treat any underlying causes.

It is important to note that the treatment of uveitis should be tailored to each individual’s specific condition, and management may require close collaboration between an ophthalmologist and a rheumatologist or immunologist. Regular follow-up appointments are crucial to monitor the response to treatment and adjust the therapy as needed.

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