In vivo Confocal Microscopy of Posner-Schlossman Syndrome: Comparison with herpes simplex keratitis, HLA-B27 anterior uveitis and acute attack of primary angle closure.

To investigate in vivo confocal microscopy (IVCM) findings in patients with Posner-Schlossman Syndrome (PSS), we compared the IVCM findings from the eyes of patients with: PSS (44 eyes); herpes simplex keratitis (HSK) (45 eyes); HLA-B27 anterior uveitis (B27AU) (45 eyes); and with acute attack of primary angle closure (aPAC) (43 eyes). The central Langerhans cells (LCs) grade at the level of corneal basal epithelial cells of the PSS group (2.33 ± 0.55) was similar to that of the HSK group (2.63 ± 0.67) (χ2 = -1.435, P = 0.174) but was significantly higher than those of the B27AU group (1.80 ± 0.79) (χ2 = 2.311, P = 0.023) and the aPAC group (1.75 ± 0.46) (χ2 = 2.701, P = 0.022). The keratocyte activation grade of the PSS group (1.55 ± 0.76) was similar to that of the HSK group (1.65 ± 0.81) (χ2 = 1.104, P = 0.675) but was significantly higher than those of the B27AU group (1.00 ± 0.71) (χ2 = 2.364, P = 0.025) and aPAC group (1.75 ± 0.46) (χ2 = 2.532, P = 0.027). The LCs and keratocyte activation grades observed by IVCM in patients with PSS were higher than those in patients with B27AU and with aPAC, but they were similar to those in patients with HSK. This implies that PSS might be related to viral infection.