In vivo confocal microscopic evaluation of keratic precipitates and endothelial morphology in Fuchs' uveitis syndrome

To evaluate the endothelial cell layer in patients with Fuchs' uveitis syndrome (FUS) with respect to the type and distribution of keratic precipitates (KP), endothelial cell morphology, and endothelial cell density (ECD), using in vivoconfocal microscopy (IVCM).

Forty eyes of 40 patients (mean age of 32.2 ± 12.5 years) with the clinical diagnosis of FUS were evaluated with IVCM (Confoscan 3.0, Vigonza, Italy). KP were classified as type I (small, round), type II (stippled), type III (dendritiform), and type IV (globular). When >1 KP type was present, differentiation between the predominant and less frequent KP was made as 'primary' and 'secondary'. ECD was measured and compared with age-matched 60 control subjects. Endothelial blebs were classified as small (3-10 μm) or large (>10 μm).

In 36 (90.0%) cases with FUS, more than one KP type was observed with IVCM. Type III (dendritiform) KP was the most frequently observed primary KP type (85.0%), followed by type II (stippled) KP (15.0%). Secondary KP included type II (58.3%), type IV (globular) (27.8%), and type III (13.9%). The mean endothelial cell density of eyes with FUS (2588 ± 396 cells/mm(2)) was significantly lower than that of control subjects (2930 ± 364 cells/mm(2)) (t-test; P<0.001). Eyes with FUS had lower proportion of hexagonal cells and higher percentage of polymegethism compared with the uninvolved contralateral eyes. Endothelial blebs (21 small, 16 large blebs) were observed in 37 (92.5%) eyes.

FUS is characterized by dendritiform KP and is associated with decreased ECD and altered endothelial cell morphology.