Clinical Signs of Uveitis
The classical clinical signs of uveitis include eye pain, blurred vision, photophobia, and headache, with slit-lamp examination revealing inflammatory cells in the anterior chamber or vitreous, and these symptoms should prompt urgent ophthalmologic referral to prevent vision loss. 1
Key Clinical Presentations by Anatomic Location
Anterior Uveitis
- Eye pain (moderate to severe)
- Photophobia (light sensitivity)
- Blurred vision
- Redness of the eye
- Headache
On examination, anterior uveitis may present with:
- Keratic precipitates on the corneal endothelium (can be fine or mutton-fat type)
- Posterior synechiae (adhesions between iris and lens) - broad-based synechiae are particularly associated with tubercular uveitis 2
- Iris nodules
- Anterior chamber cells and flare visible on slit-lamp examination 1, 3
Important distinction: Acute anterior uveitis may have sudden onset, while chronic forms (particularly when associated with Crohn's disease) are frequently bilateral, insidious in onset, and long-lasting 1.
Intermediate and Posterior Uveitis
These forms are less common but more sight-threatening 1:
- Visual disturbance and blurred vision
- Floaters (myodesopsias) 4
- Vitreous opacities ("snowballs")
- Snow banking (white inflammatory material over pars plana)
- Retinal vasculitis - particularly peripheral retinal vasculitis, which can be prominent 5, 2
- Choroiditis or retinochoroiditis
- Macular edema (cystoid macular edema is a common cause of vision loss) 6
Panuveitis
Involves all uveal layers with combined features of anterior and posterior inflammation 4.
Critical Diagnostic Features
Slit-lamp examination is essential for confirming the diagnosis and differentiating between anterior and posterior uveitis 1, 3. The examination reveals:
- Presence and grade of inflammatory cells
- Location of inflammation
- Associated structural complications
Sight-Threatening Indicators
Urgent ophthalmologic referral is mandatory when any of these features are present 1:
- Severe or moderate-to-severe eye pain
- Significant photophobia
- Visual disturbance or diminished vision
- Bilateral disease
- Vitreous haze
- Macular or optic nerve involvement
- Retinal vascular inflammation
- Macular edema
- Exudative retinal detachment
Differentiation from Episcleritis
Episcleritis must be distinguished from uveitis based on the absence of moderate-severe eye pain, photophobia, blurring, and diminished vision 1. Episcleritis presents with:
- Mild or no pain
- Hyperemic sclera and conjunctiva
- Itching and burning
- No visual changes (key differentiator)
Clinical Presentation Patterns
The onset and course vary:
- Acute anterior uveitis: Sudden onset with prominent symptoms
- Chronic uveitis: Insidious onset, often bilateral, long-lasting 1, 3
- Recurrent uveitis: Multiple episodes requiring repeated treatment
Common Pitfall
Do not rely on symptoms alone to gauge severity - symptoms may not indicate the true severity of inflammation, particularly in posterior uveitis 7. Slit-lamp examination and potentially OCT imaging are essential for accurate assessment. Patients may have significant posterior segment inflammation with relatively mild anterior symptoms.
The possibility of progression to permanent vision loss makes recognition of these signs and prompt ophthalmologic referral critical for preserving visual function 1, 3, 4.