Abstract
Purpose: :
The goal of this study was to compare the effectiveness of brimonidine use during initial Argon Laser Trabeculoplasty/Selective Laser Trabeculoplasty (ALT/SLT) procedures as an intraocular pressure (IOP) spike prophylaxis among chronic and non-chronic users of brimonidine.
Methods: :
This is a retrospective study reviewing a total of 256 charts of patients with glaucoma who underwent their first ALT or SLT procedure on a single eye. All patients were given brimonidine .15% prophylaxis 15-20 minutes prior to laser therapy. Patients were divided into 2 groups, those with chronic (≥6 months) use of brimonidine as medical therapy for glaucoma prior to ALT or SLT and non-chronic (<6 months or no exposure) users of brimonidine. The following variables were collected: Length of use of brimonidine, number of additional glaucoma medications, pre-op IOP, one hour post-op IOP, total energy, C/D ratio, 1,3,6, and 12 month follow up IOP, patient age, race, sex, type of glaucoma and comorbidities of hypertension and diabetes. An IOP spike was defined as an increase in IOP ≥3 mmHg. Data were evaluated using chi-square, Fisher exact test, paired/unpaired t-test, standard deviation and mean.
Results: :
There were 87 chronic brimonidine users and 169 non-chronic users. The mean pre-op IOP for chronic users was 18.5 (SD 4.7) mmHg and 19.5 (SD 5.1) mmHg for non-chronic users (p=0.12). An IOP spike of ≥3 was observed in 19/87 chronic users and 16/169 non-chronic users (chi-square p= 0.006) (Fisher’s exact p= 0.01). Patient age, race, sex, C/D ratio, total laser energy, type of glaucoma, and comorbidities of diabetes and hypertension were similar between the two groups. However, a significant difference was noted between the two groups with regards to the number of glaucoma medications used as medical therapy prior to ALT or SLT procedure. The chronic use group used an average of 1.4 (SD 0.8) more glaucoma medications than non-chronic users (p<0.0001).
Keywords: clinical (human) or epidemiologic studies: outcomes/complications • laser • intraocular pressure