Inflammatory Eye Disease (Uveitis, Scleritis, Episcleritis)
Inflammatory eye disease includes important causes of red eye, such as anterior uveitis, scleritis, and episcleritis. Anterior uveitis and scleritis can be sight-threatening and usually require same-day ophthalmology assessment, while episcleritis is usually benign and self-limiting.
This updated UKMLA guide covers anterior uveitis, scleritis and episcleritis: causes, risk factors, symptoms, diagnosis, complications, and management.
High-Yield Comparison Table
| Feature | Anterior uveitis | Scleritis | Episcleritis |
|---|---|---|---|
| Affected structure | Iris and ciliary body | Sclera (the deep, main wall of the eye) | Episclera (superficial to the sclera) |
| Pain | Present | Present, especially on eye movement | Mild discomfort |
| Photophobia | Present | May be present | Absent |
| Eye appearance | Ciliary injection around the cornea | Deep red / violaceous | Localised / sectoral redness |
| Vision | Affected | Normal | |
| Pupil | May be small or irregular | Normal | |
| Urgency | Same-day ophthalmology referral | Non-urgent | |
Uveitis
Uveitis is inflammation of the uvea, the pigmented middle layer of the eye, which includes the iris, ciliary body and choroid.
The most common type is anterior uveitis, which primarily affects the iris and anterior ciliary body. It is also referred to as iritis, iridocyclitis, and anterior cyclitis.
Other types include:
- Intermediate uveitis: primarily involves the anterior vitreous, ciliary body, and peripheral retina
- Posterior uveitis (least common): affects the choroid +/- retina and optic nerve
For this article, the focus is on anterior uveitis, as this is the most common and most relevant form at a non-specialist / UKMLA level.
Causes and Risk Factors
Anterior uveitis may be idiopathic or associated with an underlying cause:
| Category | Causes |
|---|---|
| Systemic autoimmune disorder (most important) |
|
| Infection |
|
| Other causes |
|
Risk factors:
- Previous uveitis
- Personal or family history of autoimmune disorders
- Smoking
- HLA-B27 +ve
- ~50% of patients with acute uveitis are HLA B27 +ve
- However, the lifetime risk of developing acute anterior uveitis in HLA-B27 +ve individuals is only 1%
Clinical Features
Acute anterior uveitis typically presents as unilateral (bilateral also possible):
- Red, painful eye
- Dull / ache pain
- Pain is worse on induced pupil constriction
- Blurred vision / reduced visual acuity
- Photophobia
- Epiphora (watery eyes)
Signs:
- Changes to pupil
- Small / constricted pupil
- Irregular pupil
- Ciliary injection around the cornea
- Hypopyon – usually only seen in severe anterior uveitis
The following is normal in anterior uveitis:
- Corneal fluorescein staining
- No discharge
- Extra-ocular movement
- IOP (can be transiently elevated)
- Eyelid, lashes and lacrimal ducts
- Lens (unless there is concurrent cataract)
Intermediate and posterior uveitis may present more with floaters, blurred vision or reduced vision, rather than the classic painful photophobic red eye of anterior uveitis.
Complications
Uveitis can be sight-threatening, particularly if recurrent, severe, chronic, or inadequately treated
- Uveitis is implicated in up to 25% of cases of legal blindness in the developing world
- Major causes of vision loss are cystoid macular oedema, secondary cataracts, and secondary glaucoma
Uveitis in the paediatric population (e.g. in JIA) is more likely to be chronic and has higher risk of complication and visual impairment.
~1/3 of children with uveitis suffer severe visual loss.
Investigation and Diagnosis
All suspected cases of uveitis should be referred urgently to ophthalmology (same-day) for diagnosis and management.
Perform the following assessment:
- Visual acuity assessment (Snellen chart)
- IOP measurement (to exclude glaucoma)
- Corneal fluorescein staining (to exclude corneal superficial injury)
Definitive test: slit lamp examination showing:
- Presence of WBCs in the anterior chamber aqueous humour
- Hazy aqueous humour due to protein leakage
Management
All suspected cases of uveitis should be referred urgently to ophthalmology (same-day) for diagnosis and management.
Do not initiate treatment in primary care unless instructed by an ophthalmologist.
Secondary care treatment depends on the underlying cause:
| Uveitis cause | Management |
|---|---|
| Non-infective uveitis | Standard treatment:
NICE CKS notes that corticosteroids may be given by several routes, including topical, oral, intravenous, intramuscular, periocular, intraocular injection, or implant. For non-specialist level, the key point is that uncomplicated anterior uveitis is usually managed with topical corticosteroids under ophthalmology supervision. Severe or chronic cases may be treated with:
|
| Infective uveitis | Appropriate anti-microbial drugs should be given in addition to corticosteroids and cycloplegics |
Scleritis
Scleritis refer to the inflammation of the sclera – the white outer wall of the eye
Causes and Risk Factors
~50% cases have an underlying autoimmune condition [Ref]
- Rheumatoid arthritis – most common
- Systemic vasculitis (e.g. giant cell arteritis, GPA)
- SLE
- Sarcoidosis
Infections account for 4-10% of scleritis cases [Ref]
Clinical Features and Diagnosis
Typical presentation:
- Red, painful eye with deep red / dark / violaceous scleral redness
- Severe, deep eye pain (often described as dull / boring / aching pain)
- Pain is worse with eye movement
- Can be severe enough to wake the patient from sleep
- Tenderness of the globe
- Visual blurring and photophobia may occur but are less prominent
The following is normal in scleritis:
- Corneal fluorescein staining
- No discharge
- Extra-ocular movement (apart from pain)
- IOP
- Eyelid, lashes and lacrimal ducts
- Lens (unless there is concurrent cataract)
Complications
Scleritis can threaten vision
It may lead to serious complications such as scleral thinning and subsequent globe perforation
Investigation and Diagnosis
All suspected cases of scleritis should be referred urgently to ophthalmology (same-day) for diagnosis and management.
Gold standard: slit-lamp examination
Topical phenylephrine drops can be applied to distinguish between scleritis and episcleritis
- In scleritis: vessels will NOT blanch
- In episcleritis: vessels will blanch (turn white)
Click to see rationale.
Other investigations are often necessary: [Ref]
- Imaging (e.g. B-scan ultrasound, CT/MRI) to assess the extent of inflammation, visualise necrosis and diagnose posterior scleritis
- A work-up for the underlying cause is necessary (e.g. autoimmune and vasculitis markers, inflammatory markers, infectious disease screening)
- Chest X-ray (to exclude sarcoidosis)
Scleritis vs episcleritis
- Clinical features
- Scleritis: red, painful eye that is worse on eye movement +/- affected vision and photophobia
- Episcleritis: red eye with mild discomfort + normal vision
- Vessels
- Deep vessels affected in scleritis and not mobile
- Superficial vessels affected in episcleritis and may be mobile
- Application of phenylephrine
- Vessels do NOT blanch in scleritis
- Vessels blanch in episcleritis
- Click to see rationale
Management
All suspected cases of scleritis should be referred urgently to ophthalmology (same-day) for diagnosis and management.
Typical 1st line management involves oral NSAIDs (e.g. ibuprofen, naproxen, indomethacin) [Ref]
Other further treatment: [Ref]
- Systemic corticosteroids
- Subconjunctival corticosteroid injections
- Immunosuppressive agents (e.g. methotrexate)
- Biologics
Episcleritis
Episcleritis is a benign inflammatory condition of the episclera – the superficial vascular layer between the conjunctiva and the sclera.
Causes and Risk Factors
Most cases are idiopathic [Ref]
Some cases are driven by an underlying systemic disorder: [Ref]
- Rheumatoid arthritis
- SLE
- Psoriatic arthritis and reactive arthritis
- Ankylosing spondylitis
- IBD
Patients with acute episcleritis often have coexisting ocular surface diseases: [Ref]
- Ocular rosacea – most common
- Dry eye
- Atopic keratoconjunctivitis
Clinical Features and Diagnosis
Acute onset of unilateral: [Ref]
- Red eye (segmental redness)
- Generally painless
- Mild localised discomfort or pain is possible
- No pain on eye movements
- Lacrimation
The following are typically normal: [Ref]
- Vision (photophobia is uncommon)
- Pupil
- Eye movement
- No discharge
- Normal corneal fluorescein staining
Scleritis vs episcleritis
- Clinical features
- Scleritis: red, painful eye that is worse on eye movement +/- affected vision and photophobia
- Episcleritis: red eye with mild discomfort + normal vision
- Vessels
- Deep vessels affected in scleritis and not mobile
- Superficial vessels affected in episcleritis and may be mobile
- Application of phenylephrine
- Vessels do NOT blanch in scleritis
- Vessels blanch in episcleritis
- Click to see rationale
Management
Unlike anterior uveitis and scleritis, which require urgent referral within 24 hours, episcleritis does not require urgent referral and can usually be managed in primary care.
Reassure the person that episcleritis is usually self-limiting and is not harmful.
If symptomatic, consider:
- Cold compress
- Artificial tears
- If there is more severe inflammation, consider topical NSAIDs or corticosteroids