In vivo 3D cellular imaging of eyes is aim of extended research grant

The National Eye Institute (Bethesda, MD) has awarded a $5 million research grant to ophthalmologist John S. Werner of the University of California-Davis and researchers at three other universities. The grant will fund continued development of technology for three-dimensional imaging of cells in the living eye.

The studies, part of the next five-year phase of a Bioengineering Research Partnership, could benefit increasing numbers of patients suffering from glaucoma and age-related macular degeneration. Cell-level imaging of eyes would provide significant advances in understanding the origins of retinal and optic nerve disease and in evaluating novel therapies for a wide spectrum of blinding diseases.

"Our project has been described as the Hubble telescope of the eye," said Werner, the project's principal investigator and a professor at the UC Davis Health System Eye Center.

"Vision and visual disorders begin at the cellular and molecular levels, yet the ability to visualize most cellular structures in vivo continues to elude scientists and clinicians," said Werner, whose research interests include changes in vision across the life span and diseases of the retina and optic nerve. "Despite extraordinary advances in retinal imaging, only a small fraction of human retinal cells have been visualized in the living eye."

The first phase of the partnership, started in 2003, combined adaptive optics and optical coherence tomography (OCT) to provide high-lateral and high-axial resolution, respectively. The initial phase also was funded by a five-year, $5 million grant from the National Eye Institute.

Led by Werner, investigators used this new instrumentation to create volume images of structures previously only visible with histology, including the photoreceptor outer segments, Fibers of Henle, individual optic nerve fiber bundles, detailed structures within the drusen, or lesions, of macular degeneration patients, and the fine structure of the lamina cribosa of the optic nerve. They developed instrumentation with sufficient resolution to image all the major retinal neurons in three dimensions.

However, while the resolution of their instruments reached the cellular scale, many cells and structures of interest were of low contrast. As a result, the major engineering focus of the next five years will be on contrast enhancement through additional imaging techniques. The resulting adaptive optics and optical coherence tomography instruments will permit human in vivo imaging with sufficient resolution and contrast to visualize the smallest of cells in the human retina.

Partner institutions include Duke University, Department of Bioengineering; Indiana University, Department of Optometry; and Lawrence Livermore National Laboratory, Physics and Advanced Technologies Section.

The project's engineering aims have parallel clinical/vision science objectives, including advancing the understanding of changes in cell layers associated with the most common worldwide diseases leading to blindness, including age-related macular degeneration and glaucoma.

More information:
John Werner's Vision Science and Advanced Retinal Imaging lab