Abstract
Purpose: :
Herpetic uveitis (HU) is a frequent infectious cause of anterior uveitis. A definite diagnosis is obtained by anterior chamber punctate and PCR. This is an invasive procedure not all patients consent to. We wanted to test the hypothesis that patients with HU have a certain pattern of inflammatory cells in the subepithelial nerve plexus of the cornea that distinguishes them from other uveitis types.
Methods: :
Patients with clinical suspicion of HU (unilateral, granulomatous anterior uveitis with IOD rise) as well as patients with Fuchs uveitis syndrome (FUS) were imaged with the HRT RCM (Heidelberg Engineering). Three images of the corneal nerve plexus were selected and evaluated for the presence of dendritic like inflammatory cells (DLCs) using a cell counting software. Means of the three cell counts were calculated and used for analysis. The contralateral unaffected eye in both groups was used as control. Diagnosis of HU was confirmed by anterior chamber punction or by clinical improvement due to Aciclovir therapy.Results were evaluated for statistical significance using a Kruskal-Wallis or a Mann Whitney U test when appropriate.
Results: :
Patients with HU had an average of 113±19.5 DLCs/mm2 (Mean ± SEM, n=6) in their corneal nerve plexus. In patients with FUS the average number of DLCs was 50.6±12.8 cells/mm2 (Mean ± SEM, n=8). In the unaffected contralateral eyes of patients with FUS only 5±2.1 cells/mm2 (Mean ± SEM, n=8) were detected. The difference between the three study groups was significant (p=0.0004). In HU patients the amount of DCLs was significantly higher than in FUS patients (p=0.029). In the contralateral unaffected eyes of HU patients appeared to be more DCLs than in healthy patients, these results have not been included in our statistical analysis yet.
Conclusions: :
Patients with HU showed large numbers of DLCs in the corneal subepithelial nerve plexus which can be detected by in vivo confocal microscopy. In patients with FUS these cells were also present but to a much smaller amount. In unaffected eyes of FUS patients the number of DLCs was very low to non existent.We conclude that high numbers of DCLs in the cornea of uveitis patients strongly support the clinical diagnosis of HU. In a next step patients with a non-infectious form of uveitis will be included in our study and tested for DLCs in their corneas.
Keywords: uveitis-clinical/animal model • imaging/image analysis: clinical • herpes simplex virus