Posterior Uveitis: A Comprehensive Guide

Overview

Posterior uveitis is an inflammatory condition affecting the back part of the uvea, which includes the choroid (a layer of blood vessels), retina (light-sensitive tissue), and optic nerve. This condition can lead to vision loss if not properly treated. Posterior uveitis accounts for about 15-20% of all uveitis cases, according to the National Eye Institute (NEI).

Who it affects: Posterior uveitis can occur at any age but is most commonly diagnosed in individuals between 20-60 years old. It affects both men and women equally. Certain populations, such as those with autoimmune diseases or infections, are at higher risk.

Prevalence: Uveitis affects approximately 1 in 4,500 people in the United States annually, with posterior uveitis being less common than anterior uveitis but often more severe (CDC).

Symptoms

Posterior uveitis symptoms often develop gradually and may affect one or both eyes. Common symptoms include:

• Blurred or decreased vision: This is often the first sign. Vision may become hazy or dim, especially in low light.
• Floaters: Small, dark spots or strings that drift across your field of vision. These are more noticeable than typical floaters and may increase suddenly.
• Flashing lights (photopsia): Brief flashes of light in your peripheral vision, often described as "stars" or "sparks."
• Painless vision loss: Unlike anterior uveitis, posterior uveitis rarely causes eye pain or redness. Vision loss can progress slowly or rapidly.
• Distorted vision (metamorphopsia): Straight lines may appear wavy or bent, similar to symptoms of macular degeneration.
• Difficulty seeing at night (nyctalopia): Reduced ability to see in low-light conditions.
• Loss of peripheral vision: In advanced cases, you may develop "tunnel vision" or blind spots.

Symptoms may worsen over days to weeks. If you experience any of these, especially sudden vision changes, seek medical attention promptly.

Causes and Risk Factors

Posterior uveitis can be caused by infections, autoimmune diseases, or other inflammatory conditions. In some cases, the cause remains unknown (idiopathic).

Common Causes:

• Infections:
  • Toxoplasmosis (most common infectious cause, especially in immunocompromised individuals).
  • Cytomegalovirus (CMV), particularly in HIV/AIDS patients.
  • Tuberculosis (TB).
  • Syphilis.
  • Herpes viruses (e.g., herpes simplex, varicella-zoster).
  • Lyme disease or cat-scratch disease (less common).
• Autoimmune or Inflammatory Diseases:
  • Sarcoidosis.
  • Behçet’s disease.
  • Vogt-Koyanagi-Harada (VKH) syndrome.
  • Multiple sclerosis (MS).
  • Lupus (systemic lupus erythematosus).
• Other Causes:
  • Trauma or eye injury.
  • Certain medications (rare).
  • Cancer (e.g., lymphoma, though very rare).

Risk Factors:

• Having an autoimmune disease.
• A weakened immune system (e.g., HIV/AIDS, chemotherapy).
• Recent infections (e.g., toxoplasmosis, TB).
• Genetic predisposition (family history of uveitis).
• Smoking (increases risk of autoimmune-related uveitis).

Diagnosis

Diagnosing posterior uveitis requires a thorough eye examination and sometimes additional tests. An ophthalmologist (eye specialist) will typically:

• Review your medical history: Including symptoms, recent illnesses, medications, and family history.
• Conduct a comprehensive eye exam:
  • Visual acuity test: Measures how well you see at various distances.
  • Slit-lamp examination: Uses a microscope to examine the front and back of the eye.
  • Ophthalmoscopy: Allows the doctor to see the retina, choroid, and optic nerve.
  • Tonometry: Measures eye pressure (to rule out glaucoma).
• Order imaging tests:
  • Optical coherence tomography (OCT): Provides detailed images of the retina.
  • Fluorescein angiography: Uses dye to highlight blood flow in the retina and choroid.
  • Indocyanine green (ICG) angiography: Helps visualize choroidal inflammation.
• Recommend blood tests or other diagnostics:
  • Blood tests for infections (e.g., toxoplasmosis, syphilis) or autoimmune markers (e.g., HLA-B27, ACE levels for sarcoidosis).
  • Chest X-ray or CT scan (to check for sarcoidosis or tuberculosis).
  • Lumbar puncture (in rare cases to rule out conditions like multiple sclerosis).

Early diagnosis is critical to prevent permanent vision loss. If you have symptoms, see an ophthalmologist promptly.

Treatment Options

Treatment aims to reduce inflammation, relieve symptoms, and prevent complications. The approach depends on the underlying cause and severity.

Medications:

• Corticosteroids: The first-line treatment to reduce inflammation.
  • Oral steroids (e.g., prednisone).
  • Intravenous steroids (for severe cases).
  • Intraocular injections (e.g., triamcinolone) or implants (e.g., fluocinolone).
• Immunosuppressants: Used if steroids are ineffective or for chronic cases.
  • Methotrexate.
  • Azathioprine.
  • Mycophenolate mofetil.
  • Cyclosporine or tacrolimus.
• Biologics: For resistant cases, especially those linked to autoimmune diseases.
  • Adalimumab (Humira).
  • Infliximab (Remicade).
• Antivirals or Antibiotics: If an infection is the cause (e.g., acyclovir for herpes, antibiotics for syphilis or TB).

Procedures:

• Vitrectomy: Surgical removal of the vitreous gel if inflammation is severe or complications like retinal detachment occur.
• Laser therapy: To repair retinal damage or reduce swelling.

Lifestyle and Supportive Care:

• Wear sunglasses to reduce light sensitivity.
• Use artificial tears to relieve dryness or discomfort.
• Monitor vision changes and report them to your doctor.
• Manage underlying conditions (e.g., diabetes, hypertension).

Living with Posterior Uveitis

Managing posterior uveitis requires ongoing care and lifestyle adjustments. Here are tips to help cope:

• Follow your treatment plan: Take medications as prescribed, even if symptoms improve.
• Attend regular eye exams: Monitor for recurrence or complications. Your doctor may recommend check-ups every 3-6 months.
• Protect your eyes:
  • Wear UV-protective sunglasses outdoors.
  • Avoid rubbing your eyes.
  • Use protective eyewear during activities that risk eye injury.
• Manage stress: Stress can worsen autoimmune-related uveitis. Techniques like meditation, yoga, or counseling may help.
• Eat a healthy diet: Foods rich in omega-3 fatty acids (e.g., fish, flaxseeds) and antioxidants (e.g., leafy greens, berries) may support eye health.
• Quit smoking: Smoking increases inflammation and worsens autoimmune conditions.
• Stay informed: Learn about your condition and join support groups (e.g., Uveitis.org).

Prevention

While not all cases of posterior uveitis can be prevented, you can reduce your risk by:

• Practicing good hygiene: Wash hands regularly to avoid infections like toxoplasmosis (e.g., after handling raw meat or cat litter).
• Getting vaccinated: Stay up-to-date on vaccines (e.g., varicella, herpes zoster) to prevent viral infections.
• Managing chronic conditions: Control autoimmune diseases (e.g., lupus, sarcoidosis) with your healthcare provider’s guidance.
• Protecting against STIs: Use protection to avoid infections like syphilis or HIV, which can lead to uveitis.
• Avoiding known triggers: If you have a history of uveitis, discuss potential triggers (e.g., certain medications) with your doctor.

Complications

Without treatment, posterior uveitis can lead to serious complications, including:

• Retinal damage or detachment: Inflammation can cause scarring or pulling on the retina, leading to detachment.
• Glaucoma: Increased eye pressure due to inflammation or steroid use.
• Cataracts: Clouding of the eye’s lens, often accelerated by long-term steroid use.
• Macular edema: Swelling of the macula (central retina), leading to central vision loss.
• Optic nerve damage: Can result in permanent vision loss.
• Chronic recurrence: Some people experience repeated flare-ups, requiring long-term treatment.

Early treatment significantly reduces the risk of these complications. Regular follow-ups are essential.

When to Seek Emergency Care

Sources and Further Reading

• Mayo Clinic: Uveitis
• National Eye Institute (NEI): Uveitis
• Centers for Disease Control and Prevention (CDC)
• World Health Organization (WHO)
• Cleveland Clinic: Uveitis
• Uveitis.org