Abstract
Purpose:
The purpose of this study is to assess the efficacy of Optical Coherence Tomography (OCT) to monitor in vivo temporal pathological changes of the retina and to correlate OCT with fundus imaging and histology in the endotoxin-induced uveitis (EIU) murine model.
Methods:
Two groups of age-matched C57BL/6J mice (n=15) received ocular injections (10 µL) of either lipopolysaccharide (LPS, 1µg/µL) or phosphate buffered saline (PBS) into the anterior chamber. OCT imaging of the retina (Bioptigen- RAS II) and fundus pictures (Micron III) were taken at 0 (un-injected controls), 3, 6, 16 hours, and 7 days after injection. Mice were sacrificed and perfused for histology (H&E stained retinal sections) at the same time points. Vitreo-retinal assessments were made for cells in the vitreous, retinal thickening, retinal structural changes, perivascular sheathing and optic nerve swelling.
Results:
The peak of vitreo-retinal changes occurred at 16 hours. At 7 days, there were decreased vitreous cells, but persistent changes were still evident in the inner retina layers. A quantitative assessment of the retinal thickening revealed an 11% increase in retina thickening in the 16 hr LPS vs. PBS treated mice. No optic nerve swelling was detected. When comparing methods of evaluation, OCT cross-sectional imaging of the retina was more sensitive than funduscopic imaging and H&E stained sections in visualizing vitreous cellular infiltrates, assessing retinal edema by measuring retinal thickening and evaluating retinal structural changes of the inner and outer retina. Fundus imaging was more sensitive than OCT En Face images in demonstrating perivascular sheathing and intra-retinal exudates.
Conclusions:
Our results confirmed that OCT En Face and cross-sectional imaging of the retina is a sensitive technique for evaluating retinal structural changes and cellular infiltrates in the EIU murine model. In concert with Fundus imaging and Histology, OCT imaging provides a more comprehensive means for assessing disease.
Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
746 uveitis-clinical/animal model •
688 retina