Purpose Previously we could show increased numbers and densities of dendritic-like cells (DLCs) in the subbasal nerve plexus of the central cornea in patients with herpetic anterior uveitis (HAU). Now we aimed to explore these and other inflammatory cells seen in this layer in different subtypes of anterior uveitis using in vivo confocal microscopy.

Methods Consecutive eyes of patients with different types of anterior uveitis, HAU, Fuchs’ uveitis syndrome (FUS), juvenile idiopathic arthritis (JIA) and human leucocyte antigen (HLA)-B27-related anterior uveitis were examined in vivo with the combination of Heidelberg Retina Tomograph II/III and Rostock Cornea Module. The contralateral eye was used as control. Inflammatory cells were defined on the basis of their morphology: type 1 (DLCs) and type 2 (cell bodies lacking dendrites). Frequencies were evaluated statistically in each group.

Results The difference between means of type 1 cells density of affected eyes in all four groups was significant (one-way analysis of variance (ANOVA) p=0.039). The difference between means of type 1 cell densities of affected eyes in patients with HAU (96.8±44.2 cells/mm², n=10) and that of patients with FUS (46.4±38.7 cells/mm², n=17) was significant (Tukey's post hoc p=0.025), whereas the difference between patients with HAU and JIA (53.3±34.5 cells/mm², n=7) and patients with HAU and HLA-B27 (63.1±59.2 cells/mm², n=10) was not significant (Tukey's post hoc p=0.181 and 0.300). In contrast, the following means resulted from the evaluation of type 2 cells: the difference between means of affected eyes in all four groups was not significant (one-way ANOVA p=0.185). Density means difference of patients with HAU (44.9±22.6 cells/mm², n=5) and that of FUS (20.0±11.0 cells/mm², n=2) and that of patients with JIA (56.0±18.3 cells/mm², n=2) and that of HLA-B27 (36.1±24.1 cells/mm², n=5) was not significant (Tukey's post hoc p=0.302, 0.877 and 0.739). The contralateral eye of all patient groups showed also an inflammatory cell infiltrate of lesser extent.

Conclusions The high density and morphology of DLCs in the central cornea of patients with HAU assessed by confocal microscopy supports the clinical diagnosis of HAU especially when compared with patients with FUS but not when compared with patients with JIA or HLA-B27.

Clinical relevance This study suggests that the non-invasive confocal microscopy of the cornea is capable of supporting a clinical diagnosis in patients with uveitis.