In Vivo Confocal Microscopy of Keratic Precipitates in Infectious Versus Noninfectious Uveitis

Abstract

To test the hypothesis that morphologic patterns of keratic precipitates (KPs) evaluated by in vivo confocal microscopy (IVCM) can differentiate infectious from noninfectious uveitis. Cross-sectional, observational case series. Sixty-eight eyes of 53 subjects with uveitis. A cross-sectional study was performed in patients with infectious and noninfectious uveitis presenting to a tertiary care eye hospital. Detailed ophthalmologic evaluation was performed in all the subjects. Keratic precipitates were studied by IVCM using the HRT II Rostock corneal module (Heidelberg Engineering GmbH, Heidelberg, Germany) and categorized on the basis of morphologic patterns. Morphology of KPs by slit-lamp biomicroscopy and confocal microscopy. The age of patients ranged from 15 to 87 years (median 40 years). Thirty-two patients were male (60.37%). Thirty-eight subjects had a unilateral presentation (71.69%) of uveitis. Infectious uveitis was seen in 38 cases (71.69%). The characteristics in KPs as seen in infectious uveitis were dendritic, central globular with dendritic, and infiltrative. In noninfectious uveitis (28.3%), stippled, globular, and multiple globular types of KPs were found. The sensitivity, specificity, and positive predictive value for specific combinations of KPs with an infectious cause were 84.21%, 93.33%, and 96.96%, respectively. In vivo confocal microscopy can act as an adjunct tool for differentiating infectious from noninfectious uveitis. A central globular with dendritic form of KPs is strongly suggestive of infectious uveitis.