Uveitis — Causes, Diagnosis, Corticosteroids & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Uveitis is inflammation of the uveal tract — the middle vascular layer of the eye comprising the iris, ciliary body, and choroid — with the potential to involve adjacent structures including the vitreous, retina, optic nerve, and sclera. It is the fifth leading cause of preventable visual impairment in developed countries, responsible for approximately 10-15% of cases of legal blindness, with an estimated incidence of 15 cases per 100,000 per year. Uveitis is anatomically classified according to the primary site of inflammation: anterior uveitis (iritis or iridocyclitis — inflammation of the iris and anterior ciliary body; the most common form, accounting for 50-60% of cases — most commonly associated with HLA-B27-related conditions); intermediate uveitis (inflammation of the pars plana, anterior vitreous, and peripheral retina — pars planitis in young adults); posterior uveitis (inflammation of the choroid — choroiditis, with or without adjacent retinal involvement); and panuveitis (inflammation of all three uveal segments simultaneously — often the most severe form and most frequently associated with systemic disease). Uveitis may be acute (sudden onset, symptomatic, limited duration, typically anterior), chronic (persistent inflammation lasting 3 months or more — often posterior or panuveitis, frequently associated with systemic autoimmune disease), or recurrent. Uveitis in adults is idiopathic in approximately 50% of cases; the remainder are associated with systemic conditions — particularly HLA-B27-related spondylarthropathies (ankylosing spondylitis, reactive arthritis, psoriatic arthritis, IBD-associated arthritis), sarcoidosis, and Behcet's disease. In children, juvenile idiopathic arthritis (JIA) — particularly ANA-positive oligoarticular JIA — is the most important cause of chronic anterior uveitis, characteristically asymptomatic and detected only on slit-lamp screening.

HLA-B27-associated uveitis: the most common identified aetiology of acute anterior uveitis (AAU) — HLA-B27 is present in 50-60% of AAU patients (vs. 8% in the general population); associated spondylarthropathies include ankylosing spondylitis (AS — the most common; 25-40% of AS patients develop AAU), reactive arthritis (Reiter's syndrome — arthritis, urethritis, conjunctivitis triad plus uveitis), psoriatic arthritis, and IBD-associated arthritis; AAU in HLA-B27-positive patients is typically acute, unilateral, alternating between eyes, and responds well to topical steroids. Sarcoidosis: granulomatous uveitis in any anatomical segment — granulomatous KPs (large 'mutton-fat' keratic precipitates), iris nodules (Busacca, Koeppe), periphlebitis, and retinal infiltrates; bilateral; associated with pulmonary sarcoidosis (hilar lymphadenopathy on chest X-ray), elevated serum ACE, and hypercalcaemia. Behcet's disease: a systemic vasculitis affecting young adults (Middle Eastern and East Asian populations) causing recurrent oral aphthous ulcers, genital ulcers, uveitis (typically bilateral posterior with hypopyon — pus in the anterior chamber), and skin lesions (erythema nodosum, pathergy); uveitis is severe and can lead to rapid visual loss without aggressive immunosuppression. Vogt-Koyanagi-Harada (VKH) disease: bilateral granulomatous panuveitis with exudative retinal detachments, sensorineural hearing loss, vitiligo, alopecia, and meningismus — affects pigmented races; associated with T-cell autoimmunity to melanocyte antigens. Sympathetic ophthalmia: rare bilateral granulomatous panuveitis following penetrating eye trauma or surgery to one eye. Infective uveitis: toxoplasmosis (Toxoplasma gondii — the most common cause of infectious posterior uveitis worldwide — focal necrotising retinochoroiditis with satellite lesion adjacent to old chorioretinal scar); cytomegalovirus (CMV) retinitis (immunocompromised — HIV — urgent treatment with valganciclovir); herpes simplex and varicella-zoster virus (HZV — anterior uveitis with iris atrophy, elevated IOP); tuberculosis (granulomatous uveitis); Lyme disease; syphilis (bilateral posterior uveitis — screen in all unexplained uveitis). Juvenile idiopathic arthritis (JIA): the most important paediatric cause — oligoarticular ANA-positive JIA; characteristically asymptomatic chronic anterior uveitis detected on mandatory slit-lamp screening (every 3-6 months). Drug-induced: rifabutin, cidofovir, sulphonamides, checkpoint inhibitors (pembrolizumab, nivolumab — immune-related adverse event).

Acute anterior uveitis (the most common presentation): classic triad of eye pain (unilateral aching or sharp periorbital pain — worsened by bright light and accommodation); photophobia (light sensitivity — from ciliary muscle and pupillary sphincter spasm); and blurred vision (from aqueous flare, cells, and sometimes corneal oedema). Eye appears red (circumcorneal — ciliary injection — distinct from conjunctival injection of conjunctivitis — the red ring is most intense around the limbus). Additional findings on examination: small irregular pupil (posterior synechiae — adhesions between the iris and anterior lens capsule from inflammation); hypopyon (visible layer of white inflammatory cells settling in the inferior anterior chamber — seen in severe anterior uveitis, Behcet's disease, and rarely infective uveitis). Anterior uveitis in HLA-B27-associated disease is typically unilateral, acute in onset, and alternating between eyes over subsequent attacks. JIA-associated uveitis (paediatric): characteristically asymptomatic — no redness, pain, or photophobia — a 'white eye with uveitis'; diagnosed only on mandatory slit-lamp screening; may present with band keratopathy (calcium deposits in the cornea) or amblyopia from undetected disease. Intermediate uveitis: floaters (vitreous cells — described as 'snow' or 'clouds' in the visual field); reduced visual acuity from vitritis and cystoid macular oedema (CMO). Posterior uveitis and panuveitis: floaters; reduced visual acuity; visual field defects; photopsia (flashes of light from vitreous traction or retinal inflammation); and scotomata (blind spots from focal retinal or choroidal inflammation). Slit-lamp findings (require ophthalmologist assessment): keratic precipitates (KPs — inflammatory cells on the corneal endothelium; small stellate KPs — non-granulomatous; large 'mutton-fat' KPs — granulomatous from sarcoid, TB, VKH, sympathetic ophthalmia); flare and cells in the anterior chamber; iris nodules; posterior synechiae.

Slit-lamp biomicroscopy by an ophthalmologist: the essential diagnostic tool — reveals the anatomical location and severity of intraocular inflammation (anterior chamber cells and flare graded 0-4+ on SUN criteria; vitreous cells and haze; choroidal or retinal lesions). Fundus examination (indirect ophthalmoscopy or fundus photography): identifies posterior segment lesions — chorioretinal infiltrates, retinal vasculitis, cystoid macular oedema (CMO), vitreous haze, retinal detachment. OCT (optical coherence tomography): the most sensitive modality for detecting cystoid macular oedema (the most common cause of visual impairment in uveitis) and monitoring treatment response. Fluorescein angiography (FFA): identifies retinal vasculitis (perivasacular leakage), retinal ischaemia, CMO (late leakage at the fovea — petaloid pattern), and choroidal new vessels. Systemic investigation (to identify underlying aetiology): full blood count, ESR, CRP; serum ACE and chest X-ray (sarcoidosis — hilar lymphadenopathy); HLA-B27 (ankylosing spondylitis — anterior uveitis); ANA (JIA); Quantiferon-TB Gold (IGRA — tuberculosis screening); VDRL and TPHA (syphilis — screen all bilateral posterior uveitis); Toxoplasma IgG serology and PCR; FTA-ABS (tertiary syphilis); angiotensin-converting enzyme (ACE); lysozyme; calcium (sarcoidosis); Lyme serology in endemic areas; and HIV test (opportunistic infections such as CMV retinitis). Aqueous or vitreous fluid PCR (intraocular fluid sampling): for diagnostic uncertainty in infective uveitis — sensitive for HZV, CMV, HSV, and Toxoplasma DNA. Behcet's disease: clinical diagnosis (International Study Group criteria — recurrent oral ulcers plus two of: genital ulcers, uveitis, skin lesions, positive pathergy test).

Treatment targets anatomical location, aetiology, and severity. Acute anterior non-infectious uveitis (the most common scenario): topical corticosteroid eye drops — prednisolone acetate 1% (most potent topical steroid) or dexamethasone 0.1% — initially applied hourly in severe inflammation, tapering over 4-8 weeks guided by slit-lamp cell counts; cycloplegic drops (cyclopentolate 1% or atropine 1%) to prevent posterior synechiae, relieve ciliary spasm pain, and dilate the pupil. Subtenon injection of triamcinolone acetonide 40 mg: for intermediate uveitis (pars planitis) or posterior uveitis with CMO; delivers corticosteroid adjacent to the posterior segment avoiding systemic side effects; risk of raised IOP and cataract. Intravitreal injection: triamcinolone (IVTA) or dexamethasone implant (Ozurdex — slow-release 0.7 mg dexamethasone for up to 6 months) for persistent posterior uveitis, CMO. Systemic corticosteroids: oral prednisolone 40-60 mg daily — for bilateral posterior uveitis, panuveitis, or intermediate uveitis with severe CMO; taper guided by disease activity. IV methylprednisolone (500-1000 mg pulse) for acute severe panuveitis (Behcet's, VKH). Steroid-sparing immunosuppressive therapy (for chronic, recurrent, or steroid-dependent uveitis): methotrexate (7.5-25 mg weekly — plus folic acid; most commonly used for JIA-associated uveitis); mycophenolate mofetil (1-3 g daily — preferred for posterior uveitis in adults); azathioprine (1-3 mg/kg/day); cyclosporine (2.5-5 mg/kg/day — useful in Behcet's and VKH but nephrotoxic); cyclophosphamide or chlorambucil (for severe refractory or sight-threatening disease). Biologic therapies: adalimumab (Humira — anti-TNF monoclonal antibody, SC 80 mg loading then 40 mg every 2 weeks) — FDA and EMA approved for non-infectious uveitis; the VISUAL-I and VISUAL-II trials demonstrated significant reduction in uveitis flares and inflammatory activity; preferred biologic for uveitis associated with JIA, ankylosing spondylitis, and Behcet's; infliximab (IV — particularly effective in Behcet's panuveitis and JIA uveitis refractory to adalimumab); secukinumab and tocilizumab (for specific refractory cases). Infective uveitis treatment: toxoplasmosis — trimethoprim-sulfamethoxazole or pyrimethamine plus sulfadiazine plus folinic acid for 6 weeks; CMV retinitis — valganciclovir 900 mg twice daily for induction then 900 mg daily maintenance in immunocompromised; HZV/HSV — systemic acyclovir or valaciclovir; TB uveitis — standard 6-month RIPE anti-TB therapy; syphilitic uveitis — IV penicillin G (2.4 million units IV four times daily for 10-14 days — treat as neurosyphilis).

Cataract: the most common complication — from chronic intraocular inflammation (posterior subcapsular cataract), topical and systemic corticosteroid use, and chronic raised IOP; occurs in 35-50% of patients with chronic uveitis; cataract surgery in active uveitis carries higher risk of postoperative inflammation and requires pre- and post-operative intensification of anti-inflammatory therapy. Raised intraocular pressure (ocular hypertension and secondary glaucoma): from trabecular meshwork blockage by inflammatory cells and debris, peripheral anterior synechiae occluding the drainage angle, and corticosteroid-induced IOP rise ('steroid responder' — occurring in 30% of patients on topical steroid therapy); may require topical or systemic glaucoma medications or surgical trabeculectomy; glaucoma is a leading cause of permanent visual loss in uveitis. Cystoid macular oedema (CMO): the most common cause of reduced visual acuity in uveitis — fluid accumulation in the outer plexiform and inner nuclear layers of the fovea detected by OCT; treated with intravitreal or subtenon corticosteroids, intravitreal anti-VEGF agents, or systemic immunosuppression. Posterior synechiae: adhesions between the posterior iris surface and the anterior lens capsule — cause irregular pupil shape, impair dilation, and in severe cases form a 360-degree ring (seclusio pupillae) that obstructs aqueous flow causing iris bombé and secondary angle-closure glaucoma — prevented by early cycloplegic dilation. Retinal detachment (exudative or tractional): from severe posterior or panuveitis — subretinal fluid accumulation or fibrous vitreoretinal traction bands. Optic nerve damage: from raised IOP (glaucomatous optic atrophy) or direct inflammatory optic neuropathy. Band keratopathy: calcium deposition in the corneal epithelium — a chronic complication most commonly seen in JIA-associated uveitis — causes corneal opacification; treated with chelation (EDTA) or laser ablation (PTK).

For patients with known HLA-B27-associated spondylarthropathy: regular ophthalmology review is essential as uveitis attacks are common (25-40% lifetime prevalence in AS) — early recognition and prompt topical treatment of acute attacks prevents complications; anti-TNF therapy for active ankylosing spondylitis significantly reduces the frequency of HLA-B27-associated AAU attacks — adalimumab (SC) reduces AAU episodes more effectively than etanercept and infliximab. For JIA patients: mandatory ophthalmology slit-lamp screening every 3-6 months (depending on JIA subtype and ANA status) is the single most important preventive strategy for detecting asymptomatic anterior uveitis before it causes band keratopathy, cataract, or amblyopia — visual outcomes are dramatically better with screening-detected vs. symptom-detected JIA uveitis. Monitoring for treatment side effects: corticosteroid-treated patients require regular IOP measurement (at every visit — 2-4 weeks initially), lens examination for steroid cataract, and bone mineral density assessment for long-term systemic steroid use. Patient education: patients with uveitis should be educated to recognise symptoms of anterior uveitis (eye pain, photophobia, redness, blurred vision) and to seek immediate ophthalmology review — delayed treatment of acute AAU results in synechiae, raised IOP, and longer recovery. Corticosteroid eye drop tapering must be gradual and supervised — abrupt discontinuation of topical steroids frequently precipitates rebound inflammation and flare. Adequate control of underlying systemic disease (AS, sarcoidosis, IBD, Behcet's) with rheumatology and appropriate systemic therapy reduces uveitis flare frequency.

Seek urgent ophthalmology assessment (same day — A&E or emergency eye department) for: any acute red eye with pain, photophobia, and reduced vision — possible anterior uveitis, acute angle-closure glaucoma, or corneal ulcer, all of which require same-day specialist assessment and treatment; sudden loss of vision in any eye — possible posterior uveitis, retinal detachment, central retinal artery or vein occlusion; and new onset of floaters and visual field defect in a patient with known uveitis — possible vitreous detachment, retinal tear, or retinal detachment. See a GP for urgent ophthalmology referral for: any persistent eye redness, pain, or photophobia for more than 48-72 hours that is not improving with simple eye drops; a child with joint pain (JIA) — JIA-associated uveitis is asymptomatic and requires automatic ophthalmology referral for slit-lamp screening; and any unexplained reduced vision or floaters in a patient with a known systemic inflammatory condition (AS, sarcoidosis, IBD, Behcet's, psoriatic arthritis). Important: uveitis can deteriorate rapidly over hours to days — do not defer ophthalmology assessment to a routine appointment if symptoms are acute.