Behçet’s Disease Uveitis

**Background:** Behçet's disease (BD) is a systemic vasculitis at the crossroads of autoimmune and autoinflammatory diseases. Uveitis is one of the most severe complications, occurring in 50-60% of patients, and is a major cause of morbidity. The age of onset is typically between 20-30 years, with young males having the worst prognosis. Panuveitis is the most common presentation, and bilateralization usually occurs within 2 years. The estimated risk of blindness at 5 years is 10-15%. Despite therapeutic advances, there remain gaps in knowledge and unmet clinical needs, including the need for earlier diagnosis, better definition of ophthalmological criteria, and optimization of biologic therapy use.

**Methods:** This is a narrative review article that synthesizes existing literature on the pathogenesis, diagnostic approaches, and therapeutic strategies for BD uveitis. The authors draw on epidemiological studies, clinical trials, observational studies, and meta-analyses to provide an updated overview. Key topics covered include epidemiology, pathophysiology (including genetic factors such as HLA-B*51 and polymorphisms in IL23R, IL10, STAT4), clinical presentations, ocular imaging modalities (fundus fluorescein angiography, optical coherence tomography, OCT angiography), treatment recommendations, and emerging therapies.

**Key Results:** The review highlights several important findings: (1) Pro-inflammatory cytokines (IL-6, TNFα, IFNγ, CXCL10) are significantly elevated in the aqueous humor of BD uveitis patients. (2) The IL-23/IL-17 pathway together with IFN-γ is associated with active intraocular inflammation. (3) Carrying the HLA-B*51 allele confers a relative risk of developing BD of 5.8. (4) In a Turkish series, the 3-year visual acuity was 20/200 or worse in 27.6% of eyes treated in 1990-1994 versus 12.9% in 2000-2004, attributed to earlier use of conventional DMARDs and biologics. (5) Infliximab (5 mg/kg) given at the onset of uveitis had a significantly faster effect in suppressing ocular inflammation than intravitreal triamcinolone or high-dose methylprednisolone. (6) A meta-analysis of anti-TNFα agents showed an overall uveitis remission rate of 68% (95% CI 0.59-0.79), visual acuity improvement rate of 60% (95% CI 0.47-0.77), and central macular thickness reduction of 112.70 μm (95% CI 72.8-153.0). (7) Tocilizumab was independently associated with complete response of uveitic macular edema compared to anti-TNFα agents (OR 2.10 [95% CI 1.06-4.06], p=0.03). (8) The Biovas study showed lower relapse rate of uveitis with infliximab every 4-6 weeks compared to adalimumab 40 mg/14 days.

**Clinical Implications:** The management of BD uveitis requires rapid and effective control of inflammation to preserve visual function and prevent irreversible structural damage. European and French recommendations advocate for systemic immunosuppressants (azathioprine, cyclosporine-A, interferon-α, anti-TNF agents) with steroids for posterior segment involvement. For sight-threatening uveitis, high-dose glucocorticoids and TNF inhibitors (infliximab 5 mg/kg or adalimumab 80 mg then 40 mg/14 days) or interferon-α are recommended. Treatment de-escalation should be considered only after 2 years of remission and after tapering steroids to ≤5 mg daily. Fluorescein angiography remains the gold standard for monitoring disease activity, as diffuse capillary leakage is an important predictor of relapse. The BOS24 scoring system may serve as an alternative when FA is unavailable. Emerging therapies include anti-IL-6 agents (tocilizumab) for refractory macular edema, and anti-IL-1 agents (anakinra, canakinumab) with variable efficacy. The therapeutic armamentarium is expanding, but further studies are needed to compare biologics and define optimal treatment duration.