Confocal scan of keratic precipitates in uveitic eyes of various etiologies

To specify confocal scan features of keratic precipitates (KPs) in uveitic eyes of various etiologies.

Confocal scan was performed on 129 eyes of 93 patients with different types of uveitis to characterize the morphologic features of KPs. The study included Fuchs heterochromic iridocyclitis (FHIC) in 50 eyes, idiopathic granulomatous uveitis in 27, herpetic anterior uveitis in 10, pars planitis associated with endotheliitis in 9, Vogt-Koyanagi-Harada syndrome in 8, multiple sclerosis-related uveitis in 7, sarcoidosis in 3, acute anterior uveitis not associated with HLA B27 in 3, acute retinal necrosis in 2, psoriatic uveitis in 2, chronic endophthalmitis in 2, sclerouveitis in 2, HLA B27-associated anterior uveitis in 2, sympathetic ophthalmia in 1, and toxoplasmosis in 1. The differences in types of KPs between various uveitic groups were analyzed.

Mean age of the patients was 32.5 +/- 11.2 (range, 14-67) years, and 58 (62.36%) were female. Bilateral involvement was observed in 36 cases (38.7%). Stippled and globular KPs were predominantly observed in almost all types of uveitis. With comparing the infectious versus noninfectious uveitis, dendritiform KPs were almost more common in infectious uveitis (P = 0.053) and smooth-rounded KPs were significantly more common in noninfectious uveitis (P = 0.000). Dendritiform KPs were observed more commonly in nongranulomatous uveitis than in the granulomatous ones (P = 0.005). Smooth-rounded KPs were more common in chronic uveitis than in the acute forms (P = 0.000). Predominant morphologies of KPs in FHIC were dendritiform (80.0%) and infiltrating (78.0%). The most commonly observed morphologies of KPs in intermediate uveitis were dendritiform (56.3%) and smooth rounded (56.3%). Cruciform KPs were more frequently seen in cases with FHIC (60.0%). In bilateral cases, the morphologic features were similar.

Morphologic features of KPs in various types of uveitis are diverse. Stippled and globular KPs may be observed in almost all types of uveitis. Certain types of KPs are more frequently associated with specific forms of uveitis, that is, smooth-rounded KPs may be an indicative of a granulomatous uveitis and infiltrating and dendritiform in infectious uveitis. Confocal scan may play a potential important role in identification of underlying mechanisms in complex forms of uveitis.