Effects of primary open angle glaucoma on connective field size in the visual cortex.

Zandberg, S.J. (2014) Effects of primary open angle glaucoma on connective field size in the visual cortex. thesis, Medicine.

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Abstract

Objective The purpose of this research is to assess the retinotopic organization of the sensory deprived visual cortex in patients with primary open angle glaucoma. Background Retinal diseases like glaucoma are known to induce visual field defects. Due to these defects a decrease of retinal input leads to changes in the visual pathways and visual cortex. A smaller optic nerve diameter and diminished gray and white matter are demonstrated. Now anatomical changes of the visual brain have been demonstrated, we want to investigate functional changes. Methods We conducted a study in which we compared functional MRI data of five glaucoma patients to two healthy age-matched controls. Two different stimuli were given during scanning: an expanding ring and alternating horizontal and vertical meridians. After preprocessing these scanning data, we performed corticocortical population receptive field analysis. This new method assesses the organization of the visual brain – even in parts that are sensory deprived – by analyzing how the activity in a voxel in one brain area (e.g. V2) can be explained by the activity in another area (e.g. V1). Results A difference in connective field size was found between glaucoma patients and healthy controls in general (p=0.009). No difference in size could be found between foveal and peripheral regions (p=0.58). Conclusion The corticocortical connections in glaucoma patients seemed to be still intact in the sensory deprived visual cortex, but to a lesser extent than in healthy controls. Although the statistical power must be increased using more data, these results are encouraging. They suggest that experimental glaucoma treatments can rely on a more or less unchanged retinotopic organization despite of prolonged loss of retinal input.

Item Type:	Thesis (Thesis)
Supervisor name:	Cornelissen, F.W. PhD and Hanekamp, S. MSc
Faculty:	Medical Sciences
Date Deposited:	25 Jun 2020 10:41
Last Modified:	25 Jun 2020 10:41
URI:	https://umcg.studenttheses.ub.rug.nl/id/eprint/282

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