Chronic Migraine Is Associated With Reduced Corneal Nerve Fiber Density and Symptoms of Dry Eye

Abstract

Background We used in vivo corneal confocal microscopy to investigate structural differences in the sub-basal corneal nerve plexus in chronic migraine patients and a normal population. We used a validated questionnaire and tests of lacrimal function to determine the prevalence of dry eye in the same group of chronic migraine patients. Activation of the trigeminal system is involved in migraine. Corneal nociceptive sensation is mediated by trigeminal axons that synapse in the gasserian ganglion and the brainstem, and serve nociceptive, protective, and trophic functions. Noninvasive imaging of the corneal sub-basal nerve plexus is possible with in vivo corneal confocal microscopy. Methods For this case–control study, we recruited chronic migraine patients and compared them with a sex- and age-similar group of control subjects. Patients with peripheral neuropathy, a disease known to be associated with a peripheral neuropathy, or prior corneal or intraocular surgery were excluded. Participants underwent in vivo corneal confocal microscopy using a Heidelberg Retinal Tomography III confocal microscope with a Rostock Cornea Module. Nerve fiber length, nerve branch density, nerve fiber density, and tortuosity coefficient were measured using established methodologies. Migraine participants underwent testing of basal tear production with proparacaine, corneal sensitivity assessment with a cotton-tip applicator, measurement of tear break-up time, and completion of a validated dry eye questionnaire. Results A total of 19 chronic migraine patients and 30 control participants completed the study. There were no significant differences in age or sex. Nerve fiber density was significantly lower in migraine patients compared with controls (48.4 ± 23.5 vs 71.0 ± 15.0 fibers/mm2, P < .001). Nerve fiber length was decreased in the chronic migraine group compared with the control group, but this difference was not statistically significant (21.5 ± 11.8 vs 26.8 ± 5.9 mm/mm2, P < .084). Nerve branch density was similar in the two groups (114.0 ± 92.4 vs 118.1 ± 55.9 branches/mm2, P < .864). Tortuosity coefficient and log tortuosity coefficient also were similar in the chronic migraine and control groups. All migraine subjects had symptoms consistent with a diagnosis of dry eye syndrome. Conclusions We found that in the sample used in this study, the presence of structural changes in nociceptive corneal axons lends further support to the hypothesis that the trigeminal system plays a critical role in the pathogenesis of migraine. In vivo corneal confocal microscopy holds promise as a biomarker for future migraine research as well as for studies examining alterations of corneal innervation. Dry eye symptoms appear to be extremely prevalent in this population. The interrelationships between migraine, corneal nerve architecture, and dry eye will be the subject of future investigations.

Choroidal thickness measurements in migraine patients during attack-free period

“…Since ophthalmologists often come across with eye related migraine complaints such as periorbital pain or visual auras, they have long been studying the mechanisms of this mysterious disease [26]. As a result, there are several studies available in the ophthalmic literature revealing relationship between migraine and dry eye, glaucoma, optic nerve/visual field changes and peripapillary retinal thinning [27][28][29][30]. As the vasogenic theory [31] is one of the two competing theories dominating the discussion of migraine pathogenesis, the choroid-being the highly vascular structure of the eye-has become the center of interest.…”

Association of dry eye disease with psychiatric or neurological disorders in elderly patients

“…In vivo confocal microscopy showed significantly decreased corneal nerve fiber density in migraine patients, and all the patients with migraine had dry eye symptoms 78. A large population-based study in Korea also revealed that patients with migraine had significantly higher risk of DED 79…”

“…Association between chronic migraine and DED was also suggested 78. In vivo confocal microscopy showed significantly decreased corneal nerve fiber density in migraine patients, and all the patients with migraine had dry eye symptoms 78.…”

The influence of pseudoexfoliative syndrome on corneal morphology based on in vivo confocal microscopy

“…Плотность нервных волокон рассчитывалась следующим образом: длина нерв-ных волокон  коэффициент (0,00075)/площадь сканирования. Коэффициент извитости рассчи-тывался автоматически [22].…”