Publication Date

2015

Document Type

Thesis

Committee Members

Subhashini Ganapathy (Committee Member), Nasser Kashou (Advisor), Marjean Kulp (Committee Member)

Degree Name

Master of Science in Biomedical Engineering (MSBME)

Abstract

Convergence Insufficiency is a binocular vision disorder, characterized by reduced ability of performing convergence eye movements. Absence of convergence causes, eye strain, blurred vision, doubled vision, headaches, and difficulty reading due frequent loss of place. These symptoms commonly occur during near work. The purpose of this study was to quantify neural correlates associated with convergence eye movements in convergence insufficient (CI) patients vs. normal binocular vision (NBV) controls, and to examine statistical differences between them. Functional magnetic resonance imaging (fMRI) scans were collected using a 3T Siemens scanner. A disparity-driven convergence task was designed using a standard block design approach, and was presented to all the subjects as a visual stimulus. Subjects performed tasks of two difficulty levels; an easy and a hard convergence task. FMRI data was analyzed using fMRI Expert Analysis Tool (FEAT) in FSL software package, and statistical data obtained from the FEAT was further analyzed in JMP to assess significant factors and interactions. Results showed significantly higher activation in the regions of interest (ROI), both in spatial extent and amplitude, of the patients compared to the controls (z-score > 2.3, p < 0.05). JMP analysis showed, hard task elicited higher activation than the easy task, in both controls and patients.

Page Count

113

Department or Program

Department of Biomedical, Industrial & Human Factors Engineering


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