Association between neurosensory abnormalities and dry eye

Dry eye affects a large number of people worldwide.A vicious cycle involving multiple factors tends to be implicated in its pathophysiology.Tear secretion is regulated by the sympathetic and parasympathetic nervous systems.Corneal nerve fibers secrete neurotransmitters and neuropeptides, which together participate in the maintenance of ocular surface homeostasis.Abnormal neuromodulation can cause abnormal tear secretion and a disruption of ocular surface homeostasis, leading to dry eye.The persistent abnormal tear film in dry eye can damage the normal repair system of ocular surface and leave the ocular surface and the lacrimal gland in a chronic inflammatory state.The cornea in dry eye patients is more sensitive to temperature change and mechanical stimulation than in healthy individuals.Symptomatic eye pain may be related to the effect of chronic inflammation on the corneal pain signal pathway.In vivo confocal microscopy and corneal esthesiometry can be used to evaluate the corneal nerve morphology and function in dry eye patients.This may ead to a more comprehensive treatment of dry eyes through the use of nerve related factors to nourish the cornea and the stimulation of neural pathways or related neural receptors to increase tear secretion.This study reviewed the relationship between neurosensory abnormalities and dry eye.