Quantitative Analysis of Anterior Chamber Inflammation Using the Novel CASIA2 Optical Coherence Tomography.

PURPOSE: We evaluated the clinical utility of a novel anterior segment optical coherence tomography (AS-OCT) device, CASIA2, to evaluate parameters indicative of anterior chamber (AC) inflammation severity in uveitis, including AC cell number, flare, and keratic precipitates (KPs).

DESIGN: Prospective evaluation of a diagnostic device.

METHODS: Uveitis eyes were classified into active and inactive groups. The number of hyper-reflective dots representing AC cells and optical density ratio (aqueous-to-air relative intensity [ARI] index) for flare qualification were calculated from AS-OCT images. Additionally, a program was designed to quantify the posterior corneal surface smoothness (PCSS) of each image for KPs evaluation. The maximum (MAX), minimum (MIN), and average (AVG) PCSS values were calculated from 128 images per eye and compared among active uveitis, inactive uveitis and control eyes. Correlations between SUN grade and both hyper-reflective dot number and ARI index were evaluated. Receiver operating characteristic (ROC) curves were constructed to test the values of these indicators for uveitis diagnosis.

RESULTS: AC hyper-reflective dot count, ARI index, PCSS-MAX and PCSS-AVG were all significantly higher in the active uveitis group than the inactive and control groups. Hyper-reflective dot count and ARI index were associated with SUN cell and flare grade. According to ROC curve analysis, PCSS-MAX was the best indicator for diagnosis of uveitis involving the anterior segment, so as the hyper-reflective dot number to distinguish active from inactive AC inflammation.

CONCLUSIONS: Quantification of AC cell number, flare and KPs using the CASIA2 device is a promising strategy for objective assessment of AC inflammation.