Keratic precipitate morphology in uveitic syndromes including Behçet's disease as evaluated with in vivo confocal microscopy

Abstract

To identify the morphologic appearance of keratic precipitates (KPs) with in vivo confocal microscopy (IVCM) in uveitic syndromes. A total of 75 eyes of 72 patients with a mean age of 38.6+/-15.1 years who had active intraocular inflammation and whose corneas had KP on slit-lamp examination were included in this study. IVCM (Confoscan 3.0, Vigonza, Italy) was used to image the part of the corneal endothelium in which KP were most densely deposited. KP were classified into five groups: type I (small, round), type II (stippled), type III (dendritiform), type IV (large, smooth-rounded), and type V (globular). When more than one type of KP was observed with IVCM, a distinction between the predominant and the less frequent KP was made as 'primary' and 'secondary' KP. In 50 (66.7%) eyes more than one type of KP was imaged. The size of the KP ranged between 5 and 150 microm. The most frequently observed primary KP type in Behçet's disease was type I (100%), in ankylosing spondylitis type II (57.1%), in Fuchs' uveitis syndrome type III (85.7%), in granulomatous uveitis type V (42.9%), in infectious uveitis type III (66.7%), and in juvenile idiopathic arthritis associated uveitis type I (66.7%). The KP types showed a statistically significant difference between different uveitic syndromes (Fisher's exact test, P<0.001). Certain KP types appear to be characteristic of various uveitic syndromes. IVCM may have a potential role in the diagnostic work-up of uveitic patients.