Abstract
Purpose :
Treatment of open angle glaucoma (OAG) involves reduction of intraocular pressure (IOP), either by reducing aqueous humor production or by improving facility of aqueous humor outflow. This is commonly done with topical medications, laser trabeculoplasty, or incisional surgery. Newer options, such as the iStent trabecular microbypass stent (Glaukos; San Clemente, CA), can be implanted during cataract extraction (CE) to further reduce both IOP and medication usage in patients with mild to moderate OAG. The purpose of this study is to determine the effect of combined CE and iStent on IOP reduction and medication use.
Methods :
A retrospective review was conducted at a large glaucoma practice for patient visits between September 2013 and September 2016. Inclusion criteria were patients with mild to moderate OAG who underwent combined CE and iStent during this time. Exclusion criteria included patients with any other type of glaucoma or prior incisional glaucoma surgery. Statistical analysis was conducted with Stata v. 13 (Houston, TX). The assumption of normality was not violated, as assessed by Shapiro-Wilk's test (p>0.05). A paired samples t-test was used to determine if there was a statistically significant difference between the pre-operative mean IOP and the number of medications used as compared to 3, 6, 9, 12, and 24 months post-operatively.
Results :
There were 54 eyes of 42 patients. Twenty-one were women and 21 were men. Average age was 77 years old, ranging from 62 to 92 years old. Average follow-up was 14.78 months, ranging from 3 to 24 months. When compared to their pre-op IOP values, patients had significantly decreased post-op IOP at 3 months (17.04 mm Hg ± 0.53 SEM vs. 14.81 ± 0.35; n=54; p≤0.0005), 6 months (17.95 ± 0.65 vs. 14.9 ± 0.48; n=40; p≤0.0005), 9 months (18.00 ± 0.63 vs. 15.27 ± 0.58; n=37; p≤0.0005), 12 months (17.63 ± 0.64 vs. 15.75 ± 0.43; n=36; p≤0.005), 18 months (18.00 ± 0.84 vs. 16.60 ± 0.72; n=25; p≤0.05) and 24 months (18.05 ± 1.00 vs. 15.70 ± 0.96; n=17; p≤0.05. When compared to pre-op number of medications used, patients had significantly less usage at 12 months (1.77 ± 0.15 vs. 0.91 ± 0.19; n=36; p≤0.005) and at 24 months post-op (1.76 ± 0.21 vs. 0.70 ± 0.22; n=17, p≤0.05).
Conclusions :
Combined CE with iStent implantation results in significantly reduced IOP and number of medications used.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.