To study the sensitivity of laser flare photometry (LFP) in monitoring anterior chamber inflammation by correlating LFP measurements with slit-lamp evaluation of aqueous cells in HLA-B27-related uveitis in a prospective trial. Slit-lamp cell evaluation was correlated with LFP-measured flare in a masked fashion in HLA-B27-related uveitis patients receiving standard topical therapy. At the time of 50 and 90% LFP flare reduction, the corresponding reduction of cells was recorded and statistically compared using the sign test. Forty-three episodes (in 43 patients) of acute anterior HLA-B27-related uveitis were included. LFP flare reduction and slit-lamp cell reduction were strongly correlated. LFP was significantly more sensitive for both 50% (P=0.001) and 90% (P=0.02) LFP flare reduction in assessing the decrease of anterior chamber inflammation. LFP was superior to slit-lamp cell evaluation in monitoring anterior chamber inflammation in uveitis. Flare, becoming a quantitative parameter when measured by LFP, rather than cells, should be considered the gold standard to measure anterior chamber inflammation in uveiti
