Acute anterior segment biometric effects of brimonidine assessed by swept source OCT supporting its use in managing visual disturbances.

This study quantified the effects of topical brimonidine 0.2% on anterior segment anatomy using swept-source optical coherence tomography (SS-OCT) in a prospective, interventional design. Seventy eyes were evaluated with the Anterion system. Baseline measurements were taken, followed by the instillation of one drop of brimonidine tartrate 0.2%. A second scan was performed 60 min later. Key outcomes included pupillary diameter (PD), angle opening distance at 500 μm (AOD500), iris thickness (IT), anterior chamber depth (ACD), lens vault (LV), lens thickness (LT), and white-to-white distance (WTW). Results showed a statistically significant reduction in PD and an increase in AOD500 and ACD after brimonidine, while IT decreased. No significant changes occurred in LV, LT, or WTW. Baseline gender differences were noted, with females exhibiting a larger PD and smaller AOD500 and ACD than males, as previously reported. The study also contributes normative biometric data for a Hispanic population, highlighting these relevant anatomical variations. Results show that brimonidine induces significant miosis and angle widening without altering lens parameters, supporting its potential use in managing postoperative photic phenomena. This study provides objective SS-OCT quantification of brimonidine's multiple acute effects.