Abstract
Abstract: :
Purpose: Myopia (nearsightedness) is a common visual condition characterized by negative refractive error and vitreous chamber elongation. Ocular elongation associated with myopia has been shown to be due in large part to extracellular matrix remodeling that occurs within the sclera. The genes that contribute to scleral structure are largely unknown and little is known about the molecular changes that occur in the sclera that contribute to the process of axial elongation during the development of myopia. The purpose of this project is to identify changes in gene expression that occur in the sclera of primate eyes during the process of active ocular elongation associated with induced myopia. Methods: Myopia was induced in four marmosets (Callithrix jacchus) either through the use of translucent occluders or negative lenses. Sclera were isolated from experimental and contra–lateral control eyes, total RNA was extracted from each sclera, and microarray analyses were performed using a 21,000 human gene glass array. Expression differences of selected genes were verified using real–time reverse transcription PCR. Results: Microarray analyses revealed numerous changes in gene expression associated with myopia development. Real–time PCR confirmed over–expression of insulin–like growth factor 2 receptor (IGF2R) and tissue inhibitor of metalloprotease 2 (TIMP2) in experimental eyes as compared with controls. Conclusions: The use of human microarrays on experimental and control marmoset sclera has provided new information on the molecular composition of the primate sclera, as well as clues as to changes in gene expression that are correlated with the rate of ocular elongation. Information obtained from future studies may be applied to the understanding of molecular events associated with the development of myopia in humans.
Keywords: myopia • extracellular matrix • sclera