TOPLINE:

In patients with glaucoma, preoperative use of the alpha-agonist brimonidine is associated with a nearly threefold increased risk for trabeculectomy failure due to elevated intraocular pressure (IOP).

METHODOLOGY:

• Researchers conducted a retrospective observational study at a single academic center in the US from January 2015 to March 2022 to evaluate the effects of certain preoperative glaucoma medications on the surgical outcomes of trabeculectomy.
• They analyzed data from 501 eyes of 501 adult patients with glaucoma (mean age, 68.27 years; 53.3% women) who underwent primary trabeculectomy.
• Preoperative and postoperative electronic medical records were extracted to capture patient demographics, diagnoses, IOP measurements, and medications and preoperative medications were matched to 43 unique formulations to ensure that all formulation percentages, brand names, and generic names were included.
• The four most prescribed medication classes for glaucoma were analyzed: alpha-agonists, prostaglandin analogs, beta-blockers, and topical or oral carbonic anhydrase inhibitors.
• Surgical failure due to elevated IOP was defined as IOP greater than 15 mm Hg or less than a 20% reduction in IOP from baseline on two consecutive follow-up visits or requiring reoperation due to high IOP; outcomes were evaluated over a 3-year postoperative period.

TAKEAWAY:

• Preoperative use of brimonidine was associated with a nearly threefold increased risk for trabeculectomy failure due to high IOP (hazard ratio [HR], 2.87; P = .002).
• Higher IOP at baseline was also associated with an increased risk for surgical failure (HR, 1.33; P = .014); conversely, use of a greater number of preoperative glaucoma medications, excluding brimonidine, was associated with a 34% lower risk for surgical failure (HR, 0.66; P = .007).
• Other topical agents such as beta-blockers, prostaglandin analogs, or carbonic anhydrase inhibitors, as well as age, sex, race, or severity of glaucoma, were not associated with a significant change in the risk for surgical failure.
• At 3 years, the estimated probability of remaining free from surgical failure due to high IOP was 81.9% in the brimonidine group and 93.36% in patients who did not receive the drug (P < .01).

IN PRACTICE:

“We hypothesize that brimonidine may induce pro-inflammatory changes in the conjunctiva and Tenon’s capsule, contributing to surgical failure,” the researchers reported.

SOURCE:

The study was led by Sen Yang, MD, and Wei-Chun Lin, MD, PhD, of the Casey Eye Institute at Oregon Health & Science University, in Portland, Oregon. It was published online in the American Journal of Ophthalmology on February 25.

LIMITATIONS:

Patients who could not tolerate or did not respond adequately to brimonidine were systematically excluded from the brimonidine group, potentially causing self-selection bias. The study consisted of patients from a single tertiary care institution, limiting generalizability to other patient populations. The retrospective design inherently carried the risk of loss to follow-up bias.

DISCLOSURES:

The study received support from an unrestricted grant from Research to Prevent Blindness and from National Institutes of Health grants to Oregon Health & Science University. The authors reported having no relevant financial conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.