Abstract
Purpose :
Trauma affecting vision is a common injury sustained in military combat today. Blast concussions after traumatic brain injury frequently lead to progressing vision problems resulting in blindness. Inflammation plays a vital role in the development of visual defects in this scenario. In this study, we hypothesized that adipose-derived stem cells (ADSC) and/or anti-inflammatory proteins released by ADSC will rescue from such blast related retinal damage and improve visual function.
Methods :
About 12 weeks old C57Bl/6 mice were subjected to 50-psi air pulse limited to a 7.5 mm diameter area on the left side of the head overlying the forebrain resulting in a mild traumatic brain injury. Within 1hr of blast injury, about 1000 ADSC labeled with maurocalcine-cy5 peptide were intravitreally delivered into left eye. Blast only and control mice received saline. At 6 weeks post injection visual function experiments were performed.
Results :
A single 50-psi blast produced visual deficits with a significant decrease in visual acuity (0.19±0.07 v/s 0.35±0.02 c/d, p<0.04) compared with no blast mice and an improvement with ADSC (0.19 ± 0.07 v/s 0.38 ± 0.03 c/d, p<0.03). Similarly, the contrast sensitivity for blast mice showed a significant increase in the contrast needed to detect 0.042 c/d (81±10 v/s 43±15, p<0.04; n=5), while the ADSC group had an improvement (81±10 v/s 41±16, p<0.05). Blast injury also resulted in a significant increase in b wave amplitude (as measured by electroretinogram) compared to control mice, and this blast induced increase was significantly improved by ADSC (54±30 v/s 143±22 microvolts, p<0.04; n=4). Finally, ADSC injected into eyes with blast associated specifically with lesions and reduced vascular leakage (mean pixel intensity 39.5±9.4 v/s 24.3±1.5 equal area of retina, p<0.05, n=5).
Conclusions :
Our findings suggest that ADSC improves visual deficits of the blast injury possibly through its anti-inflammatory properties on the retina. Although more studies are warranted, stem cell therapies will likely help to preserve the vision in soldiers with blast injuries affecting the retina. We expect these studies to teach us how ADSC work as anti-inflammatory therapies.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.