BACKGROUND: Laser flare-cell photometry enables objective and quantitative measurement of anterior chamber inflammation. Systematic data currently are used mainly for clinical research; few are yet available in uveitis. The authors prospectively studied the amount, duration, and pattern of inflammation for well-defined uveitic conditions and evaluated the potential usefulness of laser flare-cell photometry in uveitis. METHODS: Mean initial flare was calculated in HLA-B27-positive acute anterior uveitis, acute herpes zoster uveitis, acute retinal necrosis (ARN), Fuchs heterochromic cyclitis, intermediate uveitis (pars planitis-type), posterior sarcoidosis, posterior pole toxoplasmosis, and birdshot chorioretinopathy. Evolution of aqueous flare and cells was analyzed for acute anterior uveitis, ARN, and pars planitis treated for cystoid macular edema (CME), all of which received a standardized therapy. RESULTS: Blood-aqueous barrier disruption was very pronounced in acute anterior uveitis (170.2 +/- 33 photons/msecond), ARN (177.4 +/- 88 photons/msecond), moderate in posterior sarcoidosis (38.1 +/- 11 photons/msecond), acute zoster uveitis (25.8 +/- 6.1 photons/msecond), and pars planitis (19.1 +/- 2.9 photons/msecond) but only minimal in Fuchs heterochromic cyclitis (10.2 +/- 3.5 photons/msecond), toxoplasmosis (9.0 +/- 1.2 photons/msecond) and birdshot chorioretinopathy (5.7 +/- 1.1 photons/msecond). For acute anterior uveitis, ARN, and pars planitis with CME, the inflammatory patterns were determined. The potential of laser flare-cell photometry for precise follow-up and adjustment of therapy was illustrated in cases of anterior and posterior uveitis. CONCLUSION: The authors' findings show that laser flare-cell photometry allows quantitative assessment of inflammation in uveitis and contributes to improved management of patients with uveitis.