The next Oxyopia talk will be from our very own Dr. Catherine Cheng, Assistant Professor at Indiana University School of Optometry.
To attend the event, follow this link: https://iu.zoom.us/j/97860483446
Please email Dr. Cheng for the password: ckcheng@iu.edu
Title: The Eye Lens In Focus: Normal Aging and Age-related Pathologies
Abstract: The eye lens is an avascular, transparent, highly refractive and biconvex structure that fine focuses light images onto the retina, and the function of the lens is intimately tied to its shape, biomechanical properties, transparency and refractive index. Age-related changes lead to two major lens pathologies, cataracts and presbyopia. Cataracts, defined as any lens opacity, remain the leading cause of blindness in the world, and presbyopia is caused by a reduction in the lens’ ability to change shape during focusing (accommodation), and, by extension, the need for reading glasses. The WHO estimates that there are at least 1 billion people globally with unaddressed visual impairment, including 65.2 million people with cataracts and 826 million people with presbyopia. The leading cause of visual impairment is aging. Decades of study have focused on lens development and congenital cataracts, but very little is known about morphological, mechanical, refractive and cellular changes that occur with advanced age in the lens.
In this talk, I will share the results of a comprehensive study of young and very old wild-type mouse lenses, including measurements of lens size, stiffness, refractive index, transparency and cell structure. These results revealed surprising information about the causes of age-related opacities and the relationship between lens size and stiffness. These data are a baseline for continued studies of lens aging in disease models. My lab is currently investigating the effects of aging in lenses with disruptions to Eph-ephrin bidirectional signaling. Ephs are the largest class of receptor tyrosine kinases and are stimulated by a class of ligands known as ephrins. Human and mouse mutations in EphA2 and ephrin-A5 lead to congenital and age-related cataracts. I will demonstrate that Eph-ephrin signaling is not only crucial for lens transparency, but also influences lens biomechanical properties. I will also outline new experiments to probe the roles of Eph-ephrin signaling in lens aging.
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