Structure-Function Relations Revealed by High-Resolution (adaptive
optics - OCT) in vivo Retinal Imaging

John S. Werner
University of California, Davis

This seminar will describe the development of laboratory
instrumentation for three-dimensional imaging of the human retina at a
cellular scale.  The purpose is to study structure-function relations
in normal aging and in retinal and optic nerve disease.  These
instruments use adaptive optics to correct for higher-order,
temporally varying, ocular aberrations.  When combined with a fundus
camera that illuminates the retina with a light flash, it is possible
to image the cone photoreceptor mosaic due to the improvement in
lateral resolution (~ 2 micron).  Adaptive optics, however, do not
improve axial resolution so we combine this approach with an
interferometric technique, optical coherence tomography.  We will
describe how these techniques work and how we have achieved resolution
of ~3.0 micron in three dimensions.  Application of these methods
demonstrated correlations between visual performance measures
(multifocal ERG, contrast sensitivity, visual field sensitivity) and
cone densities in a variety of patients with retinal and optic nerve
diseases. Irregularities in the arrangement of cone photoreceptors of
patients, changes in photoreceptor outer segment length, as well
changes in inner retinal layers will also be described.