Wavefront sensorless adaptive optics fluorescence biomicroscope for in vivo retinal imaging in mice.

Daniel J. Wahl,Yifan Jian,Stefano Bonora,Robert J. Zawadzki,Marinko V. Sarunic

doi:10.1364/boe.7.000001

Abstract

Cellular-resolution in vivo fluorescence imaging is a valuable tool for longitudinal studies of retinal function in vision research. Wavefront sensorless adaptive optics (WSAO) is a developing technology that enables high-resolution imaging of the mouse retina. In place of the conventional method of using a Shack-Hartmann wavefront sensor to measure the aberrations directly, WSAO uses an image quality metric and a search algorithm to drive the shape of the adaptive element (i.e. deformable mirror). WSAO is a robust approach to AO and it is compatible with a compact, low-cost lens-based system. In this report, we demonstrated a hill-climbing algorithm for WSAO with a variable focus lens and deformable mirror for non-invasive in vivo imaging of EGFP (enhanced green fluorescent protein) labelled ganglion cells and microglia cells in the mouse retina.

Highlights

Small animal models of diseases are a vital component in vision research because they facilitate the understanding of underlying biological processes, the identification of potential causative genes for human disorders, and the development of therapies against vision-robbing diseases
The biomicroscope system design was computer simulated with Zemax (ZEMAX Development Corporation, Bellevue, WA) to model the spot size on the mouse retina off of the optical axis
Time course studies in mice and research on transgenic mouse models of degenerative retinal diseases stand to benefit from the incorporation of Adaptive optics (AO) with the imaging system for increased resolution across a wider range of animals, improved consistency in image resolution between time points, and for locations that are off the optical axis of the eye

Summary

Introduction

Small animal models of diseases are a vital component in vision research because they facilitate the understanding of underlying biological processes, the identification of potential causative genes for human disorders, and the development of therapies against vision-robbing diseases. Mice are commonly used for preclinical vision research due to the significant anatomical and functional similarity of their eyes to human eyes and to the availability of transgenic strains that model human diseases. Non-invasive in vivo retinal imaging has the potential to reduce the number of animals required for a study, which in turn reduces the development time and the cost of new therapies [1]. Transgenic mice expressing endogenous fluorescent markers, such as Enhanced Green Fluorescent Protein (EGFP), are important for vision research. The ability to image molecular markers has the potential to accelerate vision research by allowing retinal function to be observed in vivo and by permitting longitudinal studies of the same animal [2]. Non-invasive fluorescence imaging of the mouse retina with even higher resolution is desirable, but requires correction of optical aberrations in the mouse eye [7]

Methods

Results

Conclusion