Purpose:
Optical Coherence Tomography (OCT) is widely used in ophthalmology by providing non–invasive, high–resolution, cross sectional images of retinal structures. Animal models are very important for understanding mechanisms of disease progress. Small animals such as rats and mice are widely used as in–vivo models for various diseases, where especially mouse models have the advantage of mutant and transgenic strains. We present a new OCT system specifically designed for eye studies of small animal models.
Methods:
The OCT system is based on high–speed, ultra–high resolution Spectral Domain OCT (SDOCT) and its optical path is designed for imaging small eyes. C57BL/6 or Balb/C mice were anesthetized by Pentobarbital 40–80 mg/Kg i.p., the eye pupils were dilated by a drop of Mydriacyl 1% solution, and subsequently covered by an ultra–thin round cover glass using Methocel 2%. Mice were placed in a plastic tube to position them on the stage. The images were recorded at an angle of 30º – 40º from the sagittal line.
Results:
The mouse retina was successfully imaged in 3D. Each cross–sectional image was acquired at 29 frames per second. Its depth resolution is approximately 3 µm.
Conclusions:
The new system is able to image inner retinal structure of small mouse eyes. It can track anatomical changes during disease progression over time completely non–invasively. The new system will be used in the study of retinal degeneration caused by chronic hypoglycemia in mice with a null mutation in the glucagon receptor gene.
Keywords: imaging/image analysis: non-clinical • retina • nerve fiber layer