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Health condition · Clinically reviewed

Iritis, the painful red eye that needs the slit lamp, not the pharmacy shelf.

Anterior uveitis is treatable and, treated fast, rarely takes vision. The plan is prompt topical steroids, dilating drops and a careful look at what triggered it.

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Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a registered UK clinician before publication.

  • 02

    Sourced from guidance

    Checked against RCOphth, BASHH and BSPAR standards you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK ophthalmology practice, including biologics for chronic and refractory uveitis.

Key facts

Iritis at a glance.

The essentials, in plain English - what it is, how the pattern shapes care, and the treatments used in the UK today.

  • What it is

    Inflammation of the iris, sometimes with the ciliary body (iridocyclitis) - the anterior form of uveitis.

  • Course

    Acute (under three months), chronic (over three months) or recurrent - the pattern shapes the plan.

  • Idiopathic majority

    Around half of cases have no identified cause - the rest link to HLA-B27, infection or systemic disease.

  • Foundation therapy

    Topical corticosteroid drops (dexamethasone, prednisolone) are the mainstay - dilating drops relieve pain and prevent adhesions.

  • When to escalate

    Severe, chronic or bilateral disease may need systemic steroids, immunosuppression or biologics such as adalimumab.

  • Specialist care

    Managed by ophthalmology - with rheumatology or infectious diseases input when a systemic cause is found.

Why this guide matters

Prompt care, not paracetamol.

A painful red eye with photophobia deserves same-day ophthalmology - it is treatable, but complications form quickly if it isn’t.

  • Topical steroids are the mainstay

    Dexamethasone or prednisolone drops calm the inflammation - dosed frequently at first, then tapered over weeks under specialist review.

  • Dilating drops protect the pupil

    Atropine, cyclopentolate or tropicamide ease pain and stop the iris sticking to the lens as synechiae.

  • Systemic disease drives the workup

    HLA-B27, sarcoid, Behcet, JIA and infection all need a specialist plan - iritis is often the eye’s alarm bell for the body.

How the diagnosis is made

From painful red eye to a clear plan.

The steps a UK ophthalmologist will normally follow, in order - so you know what to expect and why.

  1. 01

    Assessing

    History and red flags

    A structured history covering pain, photophobia, blurred vision, tearing and any systemic clues - joints, gut, skin or infection risk.

  2. 02

    Assessing

    Slit-lamp examination

    The definitive assessment - cells and flare in the anterior chamber, keratic precipitates, hypopyon, synechiae and a small, sluggish pupil.

  3. 03

    Assessing

    Intraocular pressure and fundus

    IOP checked at every visit, and a dilated posterior segment look to exclude intermediate, posterior or panuveitis.

  4. 04

    Confirming

    Targeted bloods

    HLA-B27, ACE, TPHA (syphilis), Quantiferon-TB and inflammatory markers when a first attack is severe, bilateral or recurrent.

  5. 05

    Confirming

    Imaging when indicated

    Chest X-ray for sarcoidosis and TB - spinal or sacroiliac imaging when ankylosing spondylitis is suspected.

  6. 06

    Preparing

    Systemic screen

    Referral to rheumatology or infectious diseases when HLA-B27 disease, sarcoid, Behcet, JIA, syphilis, TB or Lyme is suspected.

  7. 07

    Preparing

    MDT plan

    Chronic, bilateral or sight-threatening disease is managed by specialist commissioned uveitis centres with ophthalmology and rheumatology together.

Typical timeline: same-day slit lamp to a settled plan within one to two weeks.

Symptoms

What iritis actually feels like.

A painful red eye with photophobia and blurred vision is the classic picture - with slit-lamp signs the ophthalmologist confirms.

  • Painful red eye

    A deep, aching pain around the eye - not the gritty surface pain of conjunctivitis.

  • Photophobia

    Bright light triggers sharp discomfort - often the symptom that brings patients in.

  • Blurred vision

    Inflammatory cells in the anterior chamber blur vision - and can herald posterior involvement.

  • Tearing and ciliary flush

    Reflex tearing with a ring of redness around the cornea - the ciliary flush is a classic sign.

  • Small, sluggish pupil

    The pupil is often miotic and reacts poorly - synechiae can bind it to the lens if untreated.

  • Hypopyon (severe cases)

    A visible layer of white cells in the anterior chamber - a sign of severe inflammation, sometimes seen in Behcet or HLA-B27 disease.

  • Keratic precipitates

    Clumps of inflammatory cells on the back of the cornea - seen only at the slit lamp and pointing to specific causes.

  • Red flag - sudden vision loss

    Rapid drop in vision, floaters or headache with vomiting needs same-day ophthalmology assessment.

Treatment

How iritis is treated in the UK.

Topical steroids and cycloplegics first - then intraocular, systemic and biologic options for severe, chronic or refractory disease.

  • Topical corticosteroid

    Dexamethasone or prednisolone drops - the mainstay of acute iritis, dosed frequently at first and tapered over weeks.

  • Cycloplegic drops

    Atropine, cyclopentolate or tropicamide - relieve pain from ciliary spasm and prevent posterior synechiae between iris and lens.

  • Intraocular steroid

    Selective intravitreal or periocular injections for stubborn inflammation - see /treatments/intravitreal-injection/.

  • Systemic corticosteroid

    Oral prednisolone for severe, bilateral or chronic disease - short courses under specialist care to protect vision.

  • Immunosuppression

    Methotrexate, azathioprine, mycophenolate or cyclosporine - specialist commissioned for chronic or steroid-dependent uveitis.

  • Biologics

    Adalimumab and infliximab for severe, chronic, JIA-associated, Behcet or refractory uveitis - see /treatments/adalimumab-uveitis-clinic/.

  • Treat the underlying cause

    Antimicrobials for infective causes, disease-modifying therapy for HLA-B27 arthritis, sarcoid or IBD - see /conditions/inflammatory-bowel-disease/.

  • Monitoring and prevention

    Regular IOP checks, cataract screening and MDT review at specialist commissioned uveitis centres.

What this guide is based on

The sources behind every claim on this page.

UK national guidance and specialist society standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your ophthalmologist knows your eye and history and can tell you which parts apply to you. If in doubt, get seen the same day.

  • Royal College of Ophthalmologists (RCOphth). Uveitis clinical guidance.

  • BASHH. UK national guidelines on syphilis and infective uveitis.

  • BSPAR. Standards for JIA-associated uveitis screening and treatment.

  • NICE. Adalimumab for treating non-infectious uveitis (TA460).

  • Uveitis Information Group. Patient guidance and support resources.

Red flags

When iritis needs urgent attention.

Most cases settle with prompt topical therapy. These are the situations where more is needed - and where a specialist opinion cannot wait.

  • Sudden loss of vision

    A rapid drop in acuity, new floaters or curtain-like shadow needs same-day ophthalmology assessment.

  • Severe pain with vomiting

    Consider acute angle-closure glaucoma - a red painful eye with headache and nausea is an emergency.

  • Bilateral or recurrent disease

    Both eyes involved, or repeated attacks, points to a systemic driver and needs specialist workup.

  • Hypopyon

    A visible layer of white cells signals severe inflammation - often Behcet, HLA-B27 disease or infection.

  • Raised intraocular pressure

    Steroid response or trabecular blockage can push pressures up - unmanaged, it becomes glaucoma.

  • Posterior involvement

    Vitritis, macular oedema or chorioretinitis changes the diagnosis and the treatment ladder.

  • Infection risk

    Recent travel, immunosuppression, HIV, TB exposure or STI history - infective causes must be excluded before immunosuppression.

  • Children and JIA

    Juvenile idiopathic arthritis uveitis is often silent and sight-threatening - regular BSPAR-schedule screening is essential.

  • Pregnancy

    Systemic therapy choices narrow - specialist joint ophthalmology and obstetric input is needed.

Living with it

A treatable condition, with a clear ladder.

Four things that make the biggest difference - taking the drops as prescribed, keeping every review, easing photophobia and reporting change fast.

A quiet reminder

Consistency beats intensity, every time.

Frequent early drops and a slow, careful taper give the eye its best chance of settling without adhesions or scarring.

  1. 01 Adherence

    Take the drops on time

    Frequent dosing in the first days matters - missed drops let inflammation rebound and adhesions form.

  2. 02 Follow-up

    Keep every review

    Pressure checks and slit-lamp reviews catch steroid response and complications early.

  3. 03 Sunglasses

    Ease photophobia

    Wraparound sunglasses reduce discomfort while the pupil is dilated and the eye settles.

  4. 04 Escalate

    Report new symptoms fast

    New floaters, dropping vision or a returning ache means the plan needs adjusting - don’t wait.

Frequently asked

Everything we get asked about iritis.

Quick answers on causes, diagnosis, drops, biologics and what happens without treatment.

  • What is iritis?

    Iritis is inflammation of the iris, the coloured part of the eye - often with the ciliary body, when it is called iridocyclitis. It is the anterior form of uveitis and presents with a painful red eye, photophobia, blurred vision and tearing.

  • What causes iritis?

    About half of cases are idiopathic. The rest link to HLA-B27 conditions such as ankylosing spondylitis, reactive arthritis, psoriatic arthritis and inflammatory bowel disease, to systemic disease such as sarcoidosis, Behcet or juvenile idiopathic arthritis, to infections including HSV, VZV, CMV, syphilis, TB and Lyme, or to trauma and eye surgery.

  • How is iritis diagnosed?

    The diagnosis is made at the slit lamp by an ophthalmologist - cells and flare in the anterior chamber, keratic precipitates and sometimes hypopyon or posterior synechiae. Targeted bloods, chest imaging and referral to rheumatology or infectious diseases are added when a systemic or infective cause is suspected.

  • What is the main treatment?

    Topical corticosteroid drops such as dexamethasone or prednisolone are the mainstay of acute iritis, dosed frequently and tapered over weeks. Cycloplegic drops - atropine, cyclopentolate or tropicamide - relieve pain and prevent posterior synechiae between the iris and lens.

  • When are biologics needed?

    Adalimumab and infliximab are considered for severe, chronic, bilateral, JIA-associated, Behcet or refractory uveitis. They are commissioned through specialist services and are the best-evidenced systemic option for non-infectious uveitis unresponsive to steroids and standard immunosuppressants.

  • What are the complications if iritis is left untreated?

    Untreated inflammation can cause posterior synechiae, cataract, raised intraocular pressure and glaucoma, cystoid macular oedema and permanent vision loss. Prompt topical steroid and cycloplegic therapy, with specialist follow-up, prevents most of these.

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