Abstract
Purpose :
<div style="direction: ltr;">To establish and characterize a glaucoma model in mice through the injection of plastic microspheres into the anterior chamber (AC) and measurement of intraocular pressure (IOP), retinal thinning and loss of retinal ganglion cells (RGC).</div>
Methods :
<div style="direction: ltr;">Plastic microspheres were injected into the AC of the right eye (OD) in 17 wild type (WT) mice. The left eye (OS) served as a control. IOP was measured pre injection and weekly post injection, and mice were sacrificed 4 weeks post injection. Histological analysis included measurement of retinal thickness and RGC counting. Calculations were made based on 3 consecutive areas measuring 10µm each, every 5-10 sections, to a total of 20-25 sections per eye. Mean values were calculated and compared between the study and control eyes. Optic nerve fibers density of injected and control eyes was compared using Luxol Fast Blue (LFB) staining. Optic nerves were evaluated for inflammatory reaction anti-CD45 antibodies.</div>
Results :
<div style="direction: ltr;">Mean IOP in the WT mice prior to injection was 11.1±2.5 mmHg OD and 12.2±2.9 mmHg OS. Four weeks post injection, prior to sacrifice, mean IOP was 14.5±3.3 mmHg OD and 13.2±2.9 mmHg OS. There was a significant increase in mean IOP in OD from pre injection to the end of follow-up (P=0.003). Six (35.3%) study eyes had IOP of 17 mmHg or more at the last follow-up compared with 2 (11.8%) in the control eyes. Mean retinal thickness was 193.7±15.5 microns in the study eyes compared with 223.9±15.5 microns in the control eyes (P=0.03) and mean RGC count was also reduced to 16.0±0.5 in the study eye compared with 17.6±0.7 in the control eye (P=0.005), per X20 field.
Optic nerve of study eyes showed decreased density of axons using the LFB staining.
Inflammatory reaction was identified only in the optic nerves sheaths with some infiltration to the nerve of the study eyes.</div>
Conclusions :
<div style="direction: ltr;"><div style="direction: ltr;">Injection of microspheres into the AC induces elevated IOP, thinning of retina, and loss of RGC and optic nerve axons as expected in glaucoma. The IOP differences were mild yet induced retinal thinning and RGC loss. The likely mechanism is obstruction of the trabecular meshwork. Inflammatory response may play a role in the process. This model might be of future use for examining neuroprotective therapy.</div></div>
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.