PURPOSE: The purpose of this study was to evaluate the levels of neutrophil gelatinase-associated lipocalin (NGAL) in the aqueous humor
in eyes with idiopathic acute anterior uveitis (AAU). METHODS: A comparative control study. Aqueous humor was collected from 20 eyes of 20 patients with
idiopathic AAU. The  control group included 20 aqueous samples from 20 patients about to undergo cataract surgery and without any other ocular or systemic
diseases. The level of  NGAL was determined with a commercially available ELISA kit. RESULTS: The concentration of NGAL in aqueous humor was markedly higher in
patients with idiopathic AAU than in control subjects (Mann-Whitney U test, p&lt;0.001). The level of NGAL was 139,197.38+/-183,426.36 (mean+/-SD) pg/ml in
eyes with AAU and 3,169.96+/-1,595.78 pg/ml in the eyes of the control group. CONCLUSIONS: The aqueous humor NGAL level is increased in eyes with idiopathic
AAU. These results  imply that NGAL is associated with the regulation of inflammation in patients with AAU and could be used as a biomarker of ocular
inflammation and immunomodulatory treatment response.