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Posterior Uveitis: A Complete Patient Guide

What is Posterior Uveitis?

Posterior uveitis is inflammation that affects the back (posterior) segment of the uvea—the middle layer of the eye that includes the choroid, retina, and optic nerve head. Because these structures are crucial for capturing and transmitting visual information, inflammation here can cause blurred vision, floaters, and, if left untreated, permanent vision loss.

The condition is part of a broader group called “uveitis,” which can involve the front (anterior), middle (intermediate), or back of the eye. When the inflammation is limited to the posterior segment, it is specifically termed posterior uveitis. It is usually diagnosed by an ophthalmologist using a dilated eye exam and imaging tests.

According to the Mayo Clinic, posterior uveitis accounts for roughly 10–20 % of all uveitis cases in the United States, but the exact prevalence varies worldwide because infectious and autoimmune triggers differ by region.

Common Causes

Posterior uveitis is rarely idiopathic (unknown cause). Most cases are linked to systemic infections, autoimmune diseases, or ocular-specific conditions. Below are the most frequently encountered causes (alphabetical order):

• Behçet’s disease – a systemic vasculitis that can cause recurring bursts of inflammation in the retina and choroid.
• Cytomegalovirus (CMV) retinitis – typically seen in patients with advanced HIV/AIDS or those on immunosuppressive therapy.
• Herpes simplex virus (HSV) or Varicella‑zoster virus (VZV) retinitis – viral infections that can produce necrotizing retinitis.
• Locular (Toxoplasma) retinochoroiditis – the most common cause of infectious posterior uveitis worldwide.
• Multiple sclerosis (MS) – can be associated with inflammatory lesions of the optic nerve and retina.
• Pseudotumor cerebri (idiopathic intracranial hypertension) – may trigger venous congestion leading to optic disc inflammation.
• Syphilis – a “great imitator” that can involve any ocular layer, including the posterior segment.
• Sarcoidosis – a granulomatous disease that frequently involves the choroid and retinal vasculature.
• Tuberculosis (TB) – ocular TB can produce granulomatous choroiditis.
• Vogt‑Koyanagi‑Harada (VKH) disease – an autoimmune disorder targeting melanocyte-rich tissues, causing diffuse choroidal inflammation.

Associated Symptoms

Because the retina and choroid are responsible for sharp central vision and light perception, inflammation here produces a characteristic set of visual complaints:

• Blurred or decreased central vision – often gradual but can become sudden.
• Floaters – tiny specks or cobweb‑like shapes that drift across the visual field.
• Scotomas – dark spots or "missing pieces" in the visual field.
• Photophobia – increased sensitivity to light, especially in bright environments.
• Redness or pain – less common than in anterior uveitis, but may occur if the inflammation spreads to adjacent structures.
• Colour vision changes – difficulty distinguishing reds and greens.
• Night vision problems – especially in infections like CMV retinitis.

Systemic symptoms may accompany ocular disease when an underlying systemic condition is present (e.g., fever, joint pain, skin lesions, or neurological deficits).

When to See a Doctor

Prompt evaluation is essential because irreversible vision loss can occur within weeks of symptom onset. Seek professional care if you experience any of the following:

• Sudden or progressive loss of central vision.
• New onset of many floaters, especially if they appear as dark spots rather than harmless debris.
• Unexplained flashes of light or a “curtain” effect over part of the visual field.
• Painful eye redness that does not improve with over‑the‑counter lubricants.
• Systemic signs such as fever, unexplained weight loss, joint swelling, or a recent diagnosis of an autoimmune disease.

Patients with known risk factors (e.g., HIV infection, recent travel to TB‑endemic areas, or a diagnosis of sarcoidosis) should have a low threshold for an eye examination, even if symptoms are mild.

Diagnosis

Diagnosing posterior uveitis involves a combination of clinical examination, imaging, and laboratory testing.

Clinical Examination

• Dilated fundus exam – The ophthalmologist uses binocular indirect ophthalmoscopy to view the retina, choroid, and optic nerve after pupil dilation.
• Slit‑lamp biomicroscopy – Allows detailed inspection of the retinal periphery and detection of subtle inflammatory cells.

Imaging Studies

• Optical Coherence Tomography (OCT) – Provides cross‑sectional images of retinal layers, revealing edema, sub‑retinal fluid, or scar tissue.
• Fluorescein Angiography (FA) – Highlights retinal blood‑vessel leakage, common in vasculitis or infectious retinitis.
• Indocyanine Green Angiography (ICGA) – Better for visualizing choroidal circulation; useful in sarcoidosis, VKH, and TB.
• Fundus Autofluorescence (FAF) – Detects metabolic changes in the retinal pigment epithelium.

Laboratory Tests

Because many systemic diseases can trigger posterior uveitis, targeted labs are ordered based on clinical suspicion:

• Complete blood count (CBC) and erythrocyte sedimentation rate (ESR) – for general inflammation.
• Serologic tests: syphilis (RPR/VDRL), HIV, hepatitis B/C.
• Quantiferon‑TB Gold or tuberculin skin test – to rule out ocular TB.
• Autoimmune panels: ANA, HLA‑B27, ACE level (sarcoidosis), and specific markers for Behçet’s disease.
• Polymerase chain reaction (PCR) of aqueous or vitreous fluid – high‑sensitivity method for detecting viral DNA (CMV, HSV, VZV) or Toxoplasma DNA.

Treatment Options

Therapy is tailored to the underlying cause, severity of inflammation, and risk of vision loss. Treatment may involve systemic medications, local ocular therapy, and supportive care.

Medical Management

• Corticosteroids – First‑line anti‑inflammatory agents.
  • Systemic oral prednisone (0.5–1 mg/kg/day) for widespread inflammation.
  • Intravitreal or peri‑ocular steroid injections (e.g., triamcinolone) for focal disease.
• Immunosuppressive agents – Required when steroids are insufficient or when long‑term treatment is needed.
  • Antimetabolites: methotrexate, azathioprine, mycophenolate mofetil.
  • Calcineurin inhibitors: cyclosporine, tacrolimus.
  • Biologic agents: adalimumab (approved for non‑infectious uveitis), infliximab, rituximab.
• Antimicrobial therapy – Specific to infectious etiologies.
  • CMV retinitis: oral valganciclovir or intravitreal ganciclovir.
  • Toxoplasma retinochoroiditis: pyrimethamine + sulfadiazine + folinic acid, or trimethoprim‑sulfamethoxazole.
  • Syphilitic posterior uveitis: intravenous penicillin G.
  • TB‑related uveitis: 4‑drug anti‑TB regimen (isoniazid, rifampin, pyrazinamide, ethambutol) for 6–9 months.
• Adjunctive therapies
  • Non‑steroidal anti‑inflammatory drugs (NSAIDs) for mild pain.
  • Topical cycloplegics (e.g., atropine) if there is associated anterior segment inflammation.

Home & Lifestyle Measures

• Protect eyes from bright light with sunglasses that block UV and blue light.
• Maintain a healthy diet rich in omega‑3 fatty acids (fish, flaxseed) and antioxidants (leafy greens, berries) which support retinal health.
• Control systemic conditions—keep blood glucose, blood pressure, and lipid levels within target ranges.
• Adhere strictly to medication schedules; missing doses can trigger rapid recurrences.
• Use a humidifier and preservative‑free artificial tears if you experience ocular dryness from steroid use.

Prevention Tips

While not all cases of posterior uveitis are preventable, the risk can be lowered by managing underlying systemic diseases and practising general eye‑health habits.

• Screen for and treat systemic infections early—regular HIV testing, TB screening for at‑risk individuals, and prompt treatment of syphilis.
• Control autoimmune disease activity—regular rheumatology follow‑up and adherence to disease‑modifying drugs.
• Vaccinations—Stay up‑to‑date with hepatitis B, influenza, and shingles vaccines (especially in immunocompromised patients).
• Limit exposure to sources of ocular trauma—wear protective eyewear during high‑risk activities.
• Avoid unregulated herbal or over‑the‑counter eye drops—some products can trigger inflammation.
• Regular ophthalmic exams—Annual dilated eye exams for people with known risk factors (e.g., sarcoidosis, Behçet’s disease).

Emergency Warning Signs

Key Take‑aways

Posterior uveitis is a potentially sight‑threatening inflammation of the retina, choroid, and optic nerve head. Early recognition, thorough systemic evaluation, and prompt, cause‑specific treatment are essential to preserve vision. Patients with underlying autoimmune or infectious diseases should maintain regular communication with both their primary care physician and an ophthalmologist. When in doubt, err on the side of caution—rapid eye‑specialist assessment can make the difference between full recovery and permanent visual impairment.

References:

1. Mayo Clinic. Uveitis. https://www.mayoclinic.org/diseases-conditions/uveitis/symptoms-causes/syc-20378748 (accessed June 2026).
2. American Academy of Ophthalmology. “Uveitis.” https://www.aao.org/eye-health/diseases/uveitis (accessed June 2026).
3. National Eye Institute, NIH. “Uveitis.” https://www.nei.nih.gov/learn-about-eye-health/eye-conditions/uveitis (accessed June 2026).
4. World Health Organization. “Global Report on Trachoma.” (2021). Provides data on infectious causes of posterior uveitis.
5. Cleveland Clinic. “Posterior Uveitis: Causes, Symptoms, and Treatment.” https://my.clevelandclinic.org/health/diseases/16000-posterior-uveitis (accessed June 2026).
6. Jabs DA, et al. Standardization of Uveitis Nomenclature (SUN) Working Group. *Am J Ophthalmol*. 2005;139(3):509‑516.

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