Date of Defense
Date of Graduation
Previous in vitro studies from this lab have demonstrated that injection of a hypertonic saline solution into the episcleral vein of the rat’s eye mimics the effect of glaucoma. However, the age of the rat related to the amount of cell loss in the retina ganglion cell (RGC) layer is unknown. To address this issue, we propose to analyze the correlation of age and cell loss between 3-6 month and 1-year-old Long Evan rats. When inducing glaucoma in the Long Evan rats, the left eye in each rat was left untreated and used as an internal control. In the right eye, hypertonic saline (0.05 ml of 2 mM NaCl) was injected into the episcleral vein creating scar tissue in the trabecular meshwork of the eye, reducing aqueous drainage and leading to an increase of intraocular pressure; the primary risk factors associated with glaucoma. To determine if significant cell loss occurred in the RGC layer, the number of surviving cells in the RGC layer were counted 1 month after hypertonic injections. To count these cells, whole retinas were removed from euthanized rats and retinal flat-mounts were placed in 4% paraformaldehyde for 24 hours at 4°C. Following fixation, retinas were stained with Cresyl Violet to label nuclei in the RGC layer. The number of stained cells in specific regions of the retina was counted throughout the RGC layer using the scanning capabilities of a Zeiss 510 confocal microscope. The number of cells were counted under the untreated conditions and compared to the number of RGCs that survived under treated conditions in the periphery region of the retina. The results of these studies demonstrate that there is no significant difference in the number of labeled RGCs in control eyes between the two age groups and no significant difference in cell death obtained after hypertonic injections between the two age groups. The results of these studies suggest that it would be appropriate to use adult Long Evans rats from 3 months to 1 year for any future studies involving analysis of retinal ganglion cells quantification.
Cox, Robert, "Effects of Age on Induced Glaucoma in an In Vivo Rat Model" (2013). Honors Theses. 2224.
Honors Thesis-Open Access