Rheology of Eyes

Schematic of the eye Many diseases and normal aging processes can be diagnosed by looking for chemical and mechanical changes that occur in biological material. By probing and quantifying these changes, we can not only build better diagnostics, but can gain fundamental insight to how and why the alterations happen. The ultimate goal is to use our understanding of such materials to develop methods that will delay, stop, or even reverse degenerative processes.

Optical Coherence Tomography (OCT) of the retina The eye is of particular interest because of its complexity, its function, and its huge impact on daily life. For these reasons, we are studying a range of areas in the eye. We are interested in both the sclera (the white of the eye) and its transparent extension, the cornea. Thinning and stretching of the sclera is associated with myopia, and we are looking at rheological properties to compare healthy and diseased behavior. As the first optical element of the eye, minor changes in the cornea can have large effects on vision, as has been put to use by some corrective surgeries. The vitreous humor, although mostly water, has a characterizable structure that alters with time. The mechanical properties of the vitreous appear to impact diabetic retinopathy, the leading cause of blindness in Americans age 25-75. Important questions about the function of the vitreous, how the structure changes, and on what time scales the changes occur, are all aspects of this area of research. The retina houses the sensory abilities of the eye and diseases like Age-Related Macular Degeneration (AMD) are leading causes of blindness. The degradation of vision from AMD has associated changes in the membranes which transport nutrients, which may also exhibit localized mechanical changes that can be monitored. In addition to conducting mechanical analysis, we also focus on the biochemistry of potential therapeutics intended to treat these diseases.

In order to study such diverse topics, we use a number of techniques, including:

• Shear Rheometry
• HPLC
• TLC
• UV-VIS Absorption
• Fluorescence Spectroscopy
• NMR
• OCT
• And many more…

Publications on studies of the eye from our group are referenced here.

Associated with this project:
• Charles Nickerson
• Matthew Mattson