Retina and macula · AK
Uveitis
SUN anatomy · infectious vs non-infectious · specialist treatment ladder
Last reviewed: 2026-10-06 · 潘家健醫生
Key points
- Uveitis is grouped by anatomy and infectious vs non-infectious causes; do not immunosuppress before infection is excluded.
- Do not self-use leftover steroids or repurpose other specialties’ drugs as eye drops.
- Sudden vision drop, curtain, severe pain with headache/vomiting, or suspected endophthalmitis after surgery/injection: A&E now.
- Other new red painful photophobia: same-day specialist dilated exam when possible.
What it is
The uvea is the iris, ciliary body and choroid. Uveitis is inflammation of these tissues and may involve the vitreous, retina or optic nerve. SUN anatomical classes help communication; only an ophthalmologist can diagnose after examination. This page is education — not a DIY lab panel or prescription.
Anatomical classes (SUN)
| Type | Main site | Education ballpark / associations |
|---|---|---|
| Anterior | Anterior chamber (iris / ciliary body) | Most common (~75% of uveitis) |
| Intermediate | Vitreous-predominant | Often idiopathic; some association with multiple sclerosis |
| Posterior | Retina / choroid | Infectious causes more often than anterior (toxoplasma, CMV, TB, syphilis — doctor-led work-up) |
| Panuveitis | Anterior and posterior both marked | May associate with Behçet, VKH, sarcoidosis and similar |
In acute anterior uveitis, Western teaching often links about half of cases to HLA-B27; the real share depends on ethnicity and clinic mix. Not every anterior uveitis is HLA-B27, and a positive result does not mean you must have a spondyloarthropathy. Whether to test is a doctor’s decision.
Course may be acute, recurrent or chronic.
Symptoms
- Photophobia, pain, red eye, blur
- More floaters; posterior disease may be less “red-painful” and more blur/floaters
Signs a doctor may see (not a home mirror checklist)
- Keratic precipitates, anterior-chamber flare/cells
- Posterior synechiae; irregular or poorly reactive pupil
- Snowballs / snowbank; choroidal or retinal lesions
Tests a doctor may arrange (not a DIY order set)
Blood tests, chest imaging or taps are chosen after history and examination. Education examples include CBC, ESR/CRP, HLA-B27, ACE with chest imaging, syphilis serology (e.g. TPPA/RPR). Do not treat as “autoimmune” before infection is considered.
Treatment ladder a specialist may discuss (classes, not your prescription)
- Anterior uveitis: after excluding infection, topical steroid plus a cycloplegic is often first-line
- Periocular or intravitreal steroids in selected cases — pressure and cataract trade-offs
- Systemic steroids for heavier or bilateral / posterior disease, with monitoring
- Steroid-sparing immunosuppressants as classes (e.g. methotrexate, mycophenolate, azathioprine, cyclosporine) with monitoring
- Biologics as classes (e.g. anti-TNF); product names are not listed
Complications
- Band keratopathy, cataract, secondary glaucoma
- Cystoid macular oedema, vasculitis, retinal detachment
- Long uncontrolled disease may lead to phthisis in severe cases
When urgent / same-day specialist care
- Sudden vision drop, sudden blindness, a curtain, or severe pain with headache and vomiting: go to A&E now. After surgery, a penetrating injury or an intravitreal injection, new red painful eye, a sharp vision drop or hypopyon: treat as suspected endophthalmitis and go to A&E now. Sudden blur or eye pain while immunosuppressed: go to A&E promptly / urgent eye care that can dilate. Other new red painful photophobic eyes without those red flags: same-day ophthalmic specialty dilated exam if possible.
- Clear increase in floaters without a curtain or sudden blindness: same-day dilated fundus exam if possible
Related public education video (HKOS)
Video source: Hong Kong Ophthalmological Society (HKOS) “Eyes Decoded” YouTube (public education)
This site is not affiliated with, and is not the same organisation as, the Hong Kong Ophthalmological Society (HKOS).
This is general medical information, not a diagnosis, and cannot replace an in-person consultation with a registered ophthalmologist, refraction, or a dilated fundus exam. It is not advice to use any medicine or undergo any procedure. Medicines (including off-label use), laser or surgery must be decided by a registered doctor after examination, according to indications and Hong Kong registration. Figures from the literature are published averages, not any clinic’s results. This site does not book, prescribe or refer. Do not change treatment on your own.