Noninvasive assessment of retinal morphology in mice using optical coherence tomography

Animal models are important organisms in many areas of science.
They play a key role in experimental ophthalmology because they
help to understand a variety of genetical, developmental, and
disease mechanisms and to develop new pharmaceutical and gene
therapies. Especially mice are valuable models to identify the
genes involved in vision because of the availability of diverse
genetically modified strains and the ease with which single gene
mutants can be generated. The retina as part of the brain offers
the opportunity to directly visualize changes associated with
neurodegenerative disorders and vascular alterations. There are
both morphological and functional approaches to characterize
disease phenotypes, to monitor disease progression, and to evaluate
the responsiveness to therapy, which can either be performed in
living animals (in vivo) or in respective ocular tissue (in vitro).
Whereas most functional tests, namely electroretinography (ERG),
are performed in vivo, practically all morphological methods, like
histology, are so far performed in vitro. The current need to
sacrifice animals for histological examinations at different time
points interferes with the ability to follow up disease processes
and to monitor therapeutic or side effects during the preclinical
assessment of novel genetical and pharmaceutical therapy strategies
over time in the same individuals. Optical coherence tomography
(OCT) is a novel technique to assess retinal morphology in vivo.
Commercially available OCTs have been designed for clinical
investigations in human ophthalmology. In this work, the
establishment of a commercially available OCT for the in vivo
analysis of mouse models of retinal degenerations is reported.