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Background/Objectives: Habituation and sensitization are opposite phenomena that play a role in the pathophysiology of episodic migraine and its progression to chronic migraine (CM). There have been just a few studies that have investigated these phenomena in patients with medication overuse headache (MOH) in comparison to those with chronic migraine (CM) and healthy controls (HCs), and the findings have been inconsistent. Methods: We measured and examined visual evoked potentials (VEPs) in 81 patients with MOH and 24 patients with CM, as well as 24 HCs. The VEPs were used to assess sensitization by analysing the amplitude of the first block (100 sweeps) and to evaluate habituation by measuring the amplitude response decrement after six blocks. We further examined patients diagnosed with MOH based on their acute medication type and after a 3-week acute medication withdrawal program. Results: There were no significant differences between groups in terms of the first N1-P1 VEP amplitude block and its habituation. It was found that patients with MOH had a greater drop in the amplitude of the VEP P1-N2 complex after repeated stimulation than patients with CM or HC. The VEP parameters showed no significant differences based on the specific overused drug and after a 3-week acute medication withdrawal. Conclusions: We propose that the results obtained in patients with MOH indicate an abnormal activation of inhibitory circuits in the parieto-occipital region in response to repeated modulatory stimuli. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to discover the aqueous humor proteomic changes associated with visual field indices in glaucoma patients. Methods: Aqueous humor samples were analyzed using Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS). The visual fields were analyzed with the Humphrey Visual Field analyzer. Statistical analyses were performed to discover the relationship between the aqueous humor proteins and visual field parameters including Pattern Standard Deviation (PSD), Visual Field Index (VFI), Mean Deviation (MD) and Glaucoma Hemifield Test (GHT). Results: In total, 222 proteins were identified in 49 aqueous humor samples. A total of 11, 9, 7, and 6 proteins were significantly correlated with PSD, VFI, MD, and GHT respectively. These proteins include apolipoprotein D, members of complement pathway (C1S, C4A, C4B, C8B, and CD14), and immunoglobulin family (IKHV3-9, IGKV2-28). Conclusion: Several proteins involved in immune responses (immunoglobulins and complement factors) and neurodegeneration (apolipoprotein D) were identified to be associated with abnormal visual field parameters. These findings provide targets for future studies investigating precise molecular mechanisms and new therapies for glaucomatous optic neuropathy. [ABSTRACT FROM AUTHOR]

Glaucoma is one of the most common causes of blindness worldwide, but the risk factors of glaucoma are yet to be fully understood. We investigated the relationship between the prevalence of glaucoma and trabecular meshwork (TM) length by comparing the mean TM length of a South Korean population with that of another ethnic population. We included 250 eyes of 125 patients who underwent anterior segment optical coherence tomography at Yonsei University Gangnam Severance Hospital between January 2015 and December 2017. We measured the distance from the scleral spur to Schwalbe's line in patients with open and closed angles and calculated the TM length using the open- and closed-angle ratios in the general population. The mean TM length of the patients in our study was 752 ± 116 μm. Considering the compensated data, the estimated true mean TM length in the Korean population was 793 ± 76 μm, which was similar to the mean TM length of a previously evaluated Hispanic population, but differed significantly from those of previously evaluated Asian (Chinese), Caucasian, and African-American populations (p < 0.05). Our results support the hypothesis that the development of glaucoma would be affected by TM length. [ABSTRACT FROM AUTHOR]