Glaucoma, the leading cause of irreversible blindness in the world, affects nearly 4% of the human population today (World Health Organization, 2014). The condition results from damage to the optic nerve. A controllable risk factor that can lead to damage to the nerve is high intraocular pressure (IOP). A potential solution to this problem is the iStent, a small stent that is designed to relieve pressure in the eye. Another procedure being analyzed and compared to the iStent is the Selective Laser Trabeculoplasty (SLT), a laser surgery that modestly decreases IOP. This study is a retrospective cohort study of 270 SLT-only eyes, 85 iStent-only eyes, and 16 eyes with both surgeries performed in the 5-month period. The Preoperative IOP through 24-Month IOP is then analyzed for each eye. After analysis of the data, the iStent-alone decreased the pressure, on average, by 2.5 mmHg (p=6.07x10^-5). The SLT decreased the pressure by 0.6 mmHg (p=0.03713989). Those who received both surgeries showed a decrease in pressure by 2.05 mmHg (p=0.01502573). These results show the effectiveness of the iStent in decreasing IOP. Thus, I expect to find that the iStent is a dependable solution to Glaucoma caused by high IOP in a 24-month period.