In vivo confocal microscopy of inflammatory cells in the central cornea in patients with different subtypes of anterior uveitis

Abstract

Purpose: Previously we could show increased numbers and densities of dendritic-like cells (DLC) 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: Eyes of patients with different types of anterior uveitis, Herpetic Anterior Uveitis (HAU), Fuchs Uveitis Syndrome (FUS), Juvenile Idiopathic Arthritis (JIA), Sarcoid Uveitis and HLA-B27 related anterior Uveitis, were examined in vivo with the Heidelberg Retina Tomograph II/III and Rostock Cornea Module (HRT RCM). The contralateral eye and published data on healthy eyes was used as control. Inflammatory cells were defined on the basis of their morphology: type 1 (dendritic-like cells (DLC) and type 2 (cell bodies lacking dendrites). Frequencies were determined with the in-built cell counting software and means of 3 images evaluated statistically.

Results: So far 89 eyes of 48 patients were included. The difference between means of type 1 cells density of affected eyes in all four groups was significant (One-way 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 FUS patients (46.4 ± 38.7 cells/mm2 n=17) was significant (Tukey’s Post-hoc p=0.025), whereas the difference between HAU and JIA (53.3 ± 34.5 cells/mm2 n=7) and HAU and HLA-B27 patients (63.1 ± 59.2 cells/mm2 n=10) was not significant (Tukey’s Post-hoc; p=0.181 and p=0.300). A cut-off value of 61 DLC/mm² was calculated for HAU.<br /> The difference between means of affected eyes for type 2 cells was not significant (One-way ANOVA p=0.185)<br /> Fellow eyes, even though clinically unaffected, showed an inflammatory response although to a lesser extent. In two of the groups we noticed a significant difference between affected and contralateral eye (HAU p=0.0010; FUS p=0.0199) whereas in the other groups both eyes showed similar snumbers.

Conclusions: The high density and morphology of DLC in the central cornea of patients with HAU assessed by confocal microscopy supports the clinical diagnosis of HAU especially when compared to FUS patients. Interestingly these cells are also found in eyes with other anterior uveitis subtypes and unaffected eyes, although to a lesser extent.