| The rodent has become an increasingly valuable model for human diseases and development due to its availability for genetic manipulations. Non-invasive microscopic imaging of the rodent retina would allow tracking of retinal development, disease progression, and the efficacy of therapy in single animals. Correction of the eye’s aberrations using adaptive optics (AO) could improve the resolution of in vivo rodent retinal images [1, 2], but previous attempts have been limited by the small size of its eye and the difficulty in measuring its aberrations due to poor Shack-Hartmann wavefront sensor (SHWS) spot quality.;The work in this thesis describes methods developed to measure the rodent eye optics and to optimize its retinal image quality in vivo. Our first attempt was modifying a confocal fluorescence adaptive optics scanning laser ophthalmoscope (AOSLO) originally built for imaging the primate and human eye [3] to accommodate the rat eye. Despite achieving in vivo resolution sufficient to resolve sub-cellular structures in fluorescent ganglion cells, problems were identified with aberration measurements and AO image quality. We then constructed a SHWS customized for the small mouse eye, and found a solution to the aberration measurement problem. The custom designed SHWS can favor light from a specific retinal layer and provide good wavefront spot quality. This wavefront sensor was incorporated into a confocal AOSLO custom designed for the mouse eye. High quality images were obtained in the mouse retina revealing multiple cell layers, including the photoreceptor mosaic, nerve fiber bundles, fine capillaries/blood flow, and ganglion cell bodies and fine processes. The in vivo resolution of the system was directly characterized to be sub-ìm laterally, and ∼10 μm axially. This fine resolution has allowed classification of ganglion cells in vivo. The value of the instrument was also demonstrated in two functional imaging scientific studies. |
