Abstract
Purpose: :
To investigate the effectiveness of a miniature SD-OCT system to acquire retinal scans and standardize thickness of various retinal layers in wildtype C57BL/6 mice.
Methods: :
C57BL/6 mice were analyzed via the non-invasive Bioptigen Spectral Domain Ophthalmic Imaging System for cross-sectional and en face view of the posterior segment. Mice were anesthetized, dilated, and then provided lubricating drops every 2 min. The mice were mounted into a stereotactic mouse cassette. The working distance between the SD-OCT lens and the mouse eye was approximately 5 mm. Geometric rectangular volume scans were obtained through the mouse lens 50 degree field of view, which corresponded to 1.6 x 1.6 mm dimensional area with the optic nerve head at center point. The averaged inner retinal thickness (IRT), outer retinal thickness (ORT), and individual posterior segment layers were quantified. SD-OCT scans of the right eyes were compared between animals.
Results: :
Mean (±SEM) thickness of the choriocapillaris, outer retina, and inner retina were 42.67(2.73), 103(4.16), and 120(2) µm respectively (N = 3). The mean (±SEM) thickness for the RPE, photoreceptor, outer nuclear layers were 16.67 (2.03), 23.33 (3.48), and 63 (1.53) respectively. The outer plexiform, inner nuclear, inner plexiform/ganglion cell, and the retinal nerve fiber layers were mean (±SEM) were 15.67(0.89), 30(1), 56.33(2.6), and 18(2.08), respectively. The thickness magnitudes were not significantly different among the animals studied, F (2, 27) = 0.022 (p = 0.978).
Conclusions: :
In this investigation the structural layers that comprise the posterior segment were analyzed in order to provide normative values for wild type C57BL/6 mice. We were able to show the effectiveness of this devise in acquiring accurate near histological-grade scanning and measurements of the multiple layers within the mouse posterior segment. Through the utilization of this approach, longitudinal investigations involving the characterization of retinal disease pathophysiology and pre-clinical therapeutic applications can be achieved with minimal sample sizes along with the avoidance of high tech extraocular focusing lens.
Keywords: imaging/image analysis: non-clinical • retina