Non Contact in-vivo Small Animal Ocular Imaging With Spectral Domain Optical Coherence Tomography

Abstract

 

Purpose:

 

To demonstrate the application of high resolution Spectral Domain Optical Coherence Tomography (SD-OCT) for non contact in-vivo imaging of the anterior segment and the retina of rodent eye and quantitative retinal information extraction using 3D segmentation of the OCT images.

 

Methods:

 

A high-resolution SD-OCT system with a depth resolution of ~3µm in tissue was built for in-vivo imaging of rodent eye including mouse and rat. By using two different specifically designed probes both the anterior segment and the retina of small animals can be imaged. A 6-axis animal restraint and alignment system was built for the precise positioning of the animals. The system allows non invasive non-contact in vivo 3D imaging of the rodent eyes in short time, which is promising for high throughput applications. 3D segmentation algorithms were developed for the calculation of retinal thickness map and the anterior segment parameters like the central corneal thickness.

 

Results:

 

OCT images of the retina of mice (B6/SJLF2 and CBF1 for normal retina, and rhodopsin deficient Rho^-/- for photoreceptor degeneration) and normal rats (Wistar and Long-Evans) were acquired with high quality. The OCT images compared well with histology. The calculated retinal thickness maps make successful quantitative comparison of the retinal thickness distribution between the normal and degenerative retina. High quality OCT images of the anterior segment of mouse (DBA2/J) were successful acquired.  

 

Conclusions:

 

The reported SD-OCT system accomplished the goal of non-invasive non-contact in-vivo imaging of the anterior segment and the retina of rodent eyes with high quality and short imaging time (~5 minutes, image acquisition time is 2.7 seconds). With the capability of 3D quantitative information extraction and precise spatial registration, the OCT system makes possible longitudinal studies of ocular diseases that are currently impossible to conduct.

 

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • anterior segment • retina