To evaluate the clinical changes of corneal epithelial cells, dendritic cells, endothelial cells and corneal nerves in contralateral eyes of patients with unilateral infectious keratitis.

A prospective serial case observation study was conducted in patients with unilateral infectious keratitis from January to August 2018 in the First Affiliated Hospital of Harbin Medical University.The corneal epithelial cells density, dendritic cells density, endothelial cells density, total nerve density, total number of nerves and branch nerve density were analyzed with in vivo confocal microscopy (IVCM), slit lamp microscopy was performed on all subjects to observe the conjunctiva, cornea and anterior chamber.Corneal branch nerve density and total nerve density were compared with the control group by homogeneity test of variance.This study was approved by the Ethics Committee of the First Affiliated Hospital of Harbin Medical University (No.IRB-AF/SC-04/01.0).

Slit lamp microscopy showed no significant changes in anterior segment of the contralateral uninfected eyes in the 3 groups.The corneal epithelial cells density of uninfected eyes in viral keratitis group, bacterial keratitis group and fungal keratitis group was 1 834(1 584, 2 107), 1 905(1 651, 2 332) and 1 859(1 477, 1 995)/mm², respectively, which were significantly lower than 3 479(3 080, 3 910)/mm² in the control group, the dendritic cells densities in viral keratitis group and bacterial keratitis group were 175(139, 214)/mm² and 156(118, 190)/mm², which were higher than 69(57, 76)/mm² in the control group, the differences were statistically significant (all at P<0.05). The corneal endothelial cells density of uninfected eyes in viral keratitis group was 1 107(945, 1 270)/mm², which was less than 1 905(1 651, 2 332)/mm² in the bacterial keratitis group and 1 859(1 477, 1 995)/mm² in the fungal keratitis group (both at P<0.05). The corneal nerve number and total nerve density of uninfected eyes in viral keratitis group were 10(7, 11)/mm² and (1 822.85±622.34)μm/mm², which were lower than 11(9, 13)/mm² and (2 340.91±408.70)μm/mm² in the bacterial keratitis group, with significant differences between them (P<0.05,P<0.008 3). The morphology of corneal epithelial cells and endothelial cells in each infectious keratitis group was larger than that in the control group, while the morphology and number of dendritic cells in the contralateral eye of patients with viral and bacterial keratitis increased.

In unilateral uninfected eyes of infectious keratitis, the density of corneal epithelial cells, dendritic cells, endothelial cells and corneal nerves changes correspondingly.There may be a close relationship of corneal immunity and nervous system between the two eyes.

Infectious keratitis; In vivo confocal microscopy; Corneal epithelial cells; Dendritic cells; Corneal nerve density; Corneal endothelial cells