Abstract
Abstract: :
Purpose: To study molecular changes in the human lens in vivo in normal aging and in cataract formation using the newly developed NASA–NEI Quasi–elastic or Dynamic Light Scattering (DLS) device. Methods: We studied 25 normal and 25 cataractous eyes using the DLS device. All patients gave informed consent and participated in IRB approved NEI Protocols, and underwent complete dilated eye examinations, including clinical lens grading and A scan ultrasonography to determine the exact location of the lens nucleus. Results: With aging, there were consistent and progressive increases in molecular size of both low and high molecular weight particles in the lens detected by DLS. However, in cataract patients, there are different, dramatic increases in particle size as well as loss of low molecular weight proteins detected in vivo, even while the visual acuity of patients remain 20/20. Using particle size of 800 nm as the cut–off, we are able to detect differences between normal and cataract using the DLS technique. Conclusions: The DLS technique enables us to study molecular changes which occur in normal lens aging in vivo. This also enables us to detect early molecular changes that occur in early cataract formation, as distinguished from normal age changes.
Keywords: cataract • clinical research methodology • laser