High-resolution optical coherence tomography in mouse models of genetic and induced retinal degeneration

For the study of disease mechanisms and the development of novel therapeutic strategies for retinal pathologies in human, rodent models play an important role. Nowadays, optical coherence tomography (OCT) allows three-dimensional investigation of retinal events over time. However, a detailed analysis of how different retinal degenerations are reflected in OCT images is still lacking in the biomedical field. Therefore, we use OCT to visualize retinal degeneration in specific mouse models in order to study disease progression in vivo and improve image interpretation of this noninvasive modality. We use a self-developed spectral domain OCT system for simultaneous dual-band imaging in the 0.8 mu m- and 1.3 mu m-wavelength range - the two most common spectral bands in biomedical OCT. A fiber-coupled ophthalmic scanning unit allows flexible imaging of the eye with a high axial resolution of 3 - 4 mu m in tissue. Four different mouse models consisting of one genetic (rhodopsin-deficient and three induced retinal degenerations (sodium iodate-induced damage, light-induced photoreceptor damage and Kainate neurotoxin damage) were investigated. OCT imaging was performed daily or weekly, depending on the specific degeneration model, over a time period of up to 9 weeks. Individual retinal layers that were affected by the specific degeneration could successfully be identified and monitored over the observation time period. Therefore, longitudinal OCT studies deliver reliable information about the retinal microstructure and the time course of retinal degeneration processes in vivo.