Ocular surface findings and corneal nerve changes under confocal microscopy in patients with trigeminal neuralgia

Abstract

Background The ocular nerve of trigeminus is the sensation and nutrition nerve of cornea.Whether trigeminal neuralgia affect the function of ocular surface and the morphology of corneal nerve plexus or not is below understanding.Confocal microscope is a non-invasive method for in vivo corneal examination.Objective This study was to analyze the ocular surface findings and observe the morphology and density of corneal nerve under the confocal microscopy in patients with trigeminal neuralgia.Methods Thirty-three eyes of 33 patients with trigeminal neuralgia were collected from the Department of Pain Management in Henan Provincial People's Hospital.The corneal perceptual sensitivity was examined using corneal aesthesiometer,and the function of lacrimal secretion (Schiemer Ⅰtest),tear break-up time (BUT) were performed to evaluate the influence of trigeminal neuralgia on ocular surface.The change of corneal nerve was observed under the confocal microscopy.The fellow eyes served as controls.The informed consent was obtained from the subjects before any examination.Results The fiber length of corneal perceptual sensitivity was (54.348±6.793)mm and (55.217±6.480)mm in trigeminal neuralgia group and control group without a significant difference between them (t=0.641,P=0.528).No significant differences were found in the mean value of Schiemer Ⅰtest (9.390±6.583mm vs 9.300±5.295mm) and BUT result (6.09±4.177s vs 6.13±4.799s) between trigeminal neuralgia and control group(t=0.070,P=0.945;t=-0.085,P=0.933).The densities value of corneal subepithelial nerve plexus at the nasal,temporal,superior,inferior and central area was insignificantly changed between trigeminal neuralgia group and control group(P=0.840,0.459,0.268,0.120,0.607).Tenuous,bending and circling nerve fibers were seen in corneal stroma under the confocal microscope,while the nerve fibers were strict in controls.Conclusion Trigeminal neuralgia does not dramatically affect eye surface function and corneal subbasal nerve plexus density,but corneal nerve fibers with trigeminal neuralgia are more bending than normal people. Key words: Confocal microscopy; Trigeminal neuralgia; Corneal nerve