Feasibility Study - Use of Quasielastic Light Scattering (QLS) Device in a Study of the Human Lens and Lens Opacities

This study will test the reliability of an instrument called the Quasi Elastic Laser Scattering Device (QLS) in detecting early changes in cataract formation.

Surgery is currently the only treatment for cataracts. Many laboratories, however, are researching drugs to reverse, delay or prevent cataract formation. Anti-cataract drugs presumably would be most effective given early in the course of disease. When clinical trials of these drugs are begun, dependable and standardized methods for documenting and monitoring lens opacities will be needed to test their effectiveness. The QLS was designed to detect the earliest molecular changes in cataract development. This study will evaluate the usefulness and reliability of this instrument in measuring these changes.

Normal volunteers and patients with cataracts in this study will have a standard eye examination, including a vision test and eye pressure measurement. The pupils will be dilated for QLS testing and for examination of the retina. Photographs of the retina may be taken. The QLS test uses a very dim laser light similar to that used to scan grocery items in the supermarket. The laser beam is projected into the lens of the eye, and the scattered light is collected and analyzed to determine normal and abnormal molecular interactions in the lens. Two measurements will be done for each eye. The test will be repeated in 6 months to determine reproducibility of the system.