All ETDs from UAB

Advisory Committee Chair

Thomas T Norton

Advisory Committee Members

Christine A Curcio

Michael R Frost

Paul D Gamlin

Christianne E Strang

Shu-Zhen Wang

Document Type

Dissertation

Date of Award

2014

Degree Name by School

Doctor of Philosophy (PhD) School of Optometry

Abstract

During the development of induced myopia and recovery, the emmetropization mechanism is stimulated to modulate ocular growth. Emmetropization signals originate in the retina, are transmitted and transformed by retinal pigment epithelium (RPE) and choroid, and reach sclera to induce tissue remodeling. Induced myopia occurs in response to myopiagenic stimuli - minus lens, form deprivation, and darkness - (three GO conditions) which increase ocular elongation; recovery from lens-induced myopia (STOP) occurs when minus-lens wear is discontinued after complete compensation, slowing ocular elongation. This dissertation examined gene expression signatures in the retina, RPE, and choroid under GO and STOP conditions to examine the signaling that occurs in these compartments of the direct emmetropization pathway. Specific Aim 1 examined gene expression signatures in the retina and RPE in early GO conditions and tested two hypotheses: a) gene expression in the RPE is hidden in the combined retina+RPE; b) the gene expression signature in the combined retina+RPE predominantly resembles retina alone. Specific Aim 2, examined gene expression in the choroid, testing two hypotheses: a) the gene expression signatures in the choroid in response to three GO visual conditions (minus-lens wear, form deprivation, and continuous darkness) will have some mRNA changes that are common to all three conditions and may be essential parts of the choroidal GO signals. b) the GO expression pattern will differ from the STOP pattern. In Specific Aim 1, mRNA levels for 44 candidate genes were measured in treated eyes and compared with mRNA levels in control eyes in the retina, RPE, and combined retina+RPE in early GO. It was found that gene expression signatures in the retina and combined retina+RPE were similar, while the RPE gene expression was hidden in the combined retina+RPE. In Specific Aim 2, mRNA levels for 77 candidate genes were measured in treated eyes compared with control eyes in the choroid. It was found that a) three different GO conditions produced similar gene expression signatures; b) the GO and STOP conditions produced very different gene expression signatures. This project elucidated gene expression signatures in different compartments during myopia development and recovery, and enhanced the knowledge of emmetropization signaling.

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Optometry Commons

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