Pathophysiological changes in uninfected eye of unilateral infectious keratitis

Infectious keratitis often occurs in single eye and causes changes in the nervous system, immune system and tear function, which may affect contralateral uninfected eye.Changes in the uninfected eye include a decrease in corneal nerve density and tear secretion, an increase in corneal dendritic cells and changes in tear cytokines.All the changes can be observed by in vivo confocal microscopy, Schirmer test I and tear film break-up time tests.Alternations in immune cells, cytokines and immunodulatory neuropeptide levels in contralateral eyes might mediate the incidence of bilateral infectious keratitis, and are also correlated with lacrimal reflex pathway.This article reviewed the pathophysiological changes in the contralateral uninfected eye of monocular infectious keratitis, which may help increase our understanding of the mechanisms involved in the corneal homeostasis and pathophysiology of corneal diseases. Key words: Infectious keratitis; Uninfected eye; Nervous system; Immune system; Schirmer test I; Lacrimal cytokines