Scripties UMCG - Rijksuniversiteit Groningen
 
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Fiber quantification of the optic radiation in patients with a monocular visual field defect due to primary open angle glaucoma

(2017) Timmer, A.L.

Purpose: Glaucoma is a major cause of visual impairment and blindness in the world and is characterized by progressive degeneration of retinal ganglion cells and their axons. This causes a defect in the visual field and in the end leads to blindness. Previous research showed evidence for neurodegeneration in the visual pathway and in the brain. In this study we hope to find more information about neurodegeneration in the optic radiation (OR) in patients with primary open angle glaucoma (POAG).
Methods: A Diffusion-Weighted Imaging scan was made from 17 subjects with a monocular visual field defect due to POAG and 17 healthy subjects. Manually we created different regions of interests to reconstruct the left and right OR for each subject with fiber tracking. With fiber quantification (FQ) it was possible to make Tract Profiles of water diffusion for every OR.
Results: The mean Tract Profile for glaucoma subjects had overall lower Fractional Anisotropy (FA) values when compared with the Tract Profile of healthy subjects. These lower FA values indicate neuroanatomical changes in the OR due to the disease glaucoma. Moreover, we found indications the severity of the visual field defect may influence the OR and cause neuro anatomical changes in glaucoma subjects.
Conclusions: Evidence was found for white matter abnormalities in the OR due to (transsynaptic) neurodegeneration. Moreover, the severity of the visual field defect may influence the OR and may cause neurodegeneration in glaucoma subjects. Besides, the analysis method FQ can be used for future research to acquire more knowledge about the pathology and especially the cause of neurodegeneration in the visual pathway and beyond in glaucoma. Finally, FQ has a lot of potential to be use






 
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