Retinal Nerve Fiber Layer Area in Aging and Glaucoma

University Of Houston, Houston TX

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Linked publications & trials

Abstract

DESCRIPTION (provided by applicant): The primary objective of this career training proposal is the provide an academic optometrist with the didactic and laboratory training necessary to be an independent researcher. The objective of this project is to improve the precision and accuracy of in vivo measures of the retinal nerve fiber layer (RNFL), a surrogate for the ganglion cell content within the eye, using customized scans for the early detection or progression of glaucoma. Glaucoma is a group of diseases that can lead to irreversible blindness if left untreated. It is estimated that by the year 2030, 37 million individuals worldwide will be blinded by this disease, with 82% of these individuals being over the age of 50. In the United States, glaucoma is a significant public health problem, affecting 2.2 million individuals, and being a leading cause of blindness. Having an elusive cause, the diagnosis or progression of glaucoma is often made by direct assessment of the optic nerve, evaluating the integrity of the retinal nerve fiber layer (RNFL) and measuring the sensitivity of the visual field. Advances in imaging technology allow for an objective assessment of the retina and optic nerve. Specifically, spectral domain optical coherence tomography (SD-OCT) allow for up to 75m axial resolution. A 12 degree circular scan centered on the optic nerve is often used clinically for measuring the thickness of the RNFL. For an accurate and precise assessment of the RNFL, it is important to account for factors such as ocular magnification and the contribution of the non-neuronal content. Using non-invasive methodologies to measure ocular biometry, ocular magnification can be computed. Although glial tissue and small retinal vessels cannot be visualized in SD-OCT scans, the major retinal vessels cast shadows on the underlying tissues, and can be accounted for. The goal of the project is to investigate RNFL thickness and area measures after consideration of ocular magnification and compensation for major retinal vasculature. In particular, these methodologies will be used to 1) investigate changes in the thickness and cross sectional area of the RNFL with glaucoma disease progression in the non-human primate model; 2) investigate RNFL measures and the vascular contribution to the RNFL that occur with normal ageing; 3) investigate RNFL measures and the functional relationship to visual fields in glaucoma patients. Clinical implementation of this technology will improve the diagnostic accuracy and treatment outcomes of patients with glaucoma.