corneal epithelial dendritic cells and subbasal corneal nerve plexus in herpes simplex keratitis versus acanthamoeba keratitis

purpose: to investigate confocal scan features of corneal subbasal nerve plexus and epithelial dendritic cells in herpes simplex keratitis (hsk) as compared to acanthamoeba keratitis (ak). methods: confocal scan records of patients with clinical and confocal microscopic features compatible with hsk and ak as well as confocal scan records of normal participants were reviewed. the density and morphologic parameters of epithelial dendritic cells (edcs) and changes in subbasal nerve plexus (snp) were evaluated and compared among the groups. results: a total of 52 eyes of 52 patients were enrolled: 12 eyes (23.08%) of 12 patient with clinical and confocal scan features of hsk, 20 eyes of 20 patients (38.46%) with clinical and confocal scan results compatible with ak, and 20 eyes (38.46%) of 20 normal subjects. mean density, numbers, and area of edcs were significantly increased in both hsk and ak groups compared to the controls (p<0.001). main nerve trunk number, nerve branches, total nerve numbers, nerve diameter and subbasal nerve density were statistically lower in hsk and ak groups as compared to the controls (p<0.001). nerve tortuosity was significantly decreased in hsk and ak groups in comparison to the normal eyes (p=0.013). no statistically significant difference was observed between the hsk and ak groups in abovementioned parameters. conclusion: using confocal scan, this study showed significant changes in mean density and morphometric parameters of snp and edcs in hsk and ak. the findings can indicate a strong interaction between immune response and corneal innervation in these two corneal diseases.