Netarsudil 0.02% Alters Episcleral Venous Flowrates: A Clinical Trial Using Erythrocyte-Mediated Angiography
Objective: To assess the impact of netarsudil 0.02% on episcleral blood flow in treatment-naive glaucoma suspect or ocular hypertension patients.
Design: Prospective, unmasked, single-arm cohort study.
Participants: Ten treatment-naive individuals diagnosed with glaucoma suspect or ocular hypertension.
Methods: Erythrocyte-mediated angiography (EMA) was used to evaluate episcleral erythrocyte velocity, vessel diameter, and blood flow at baseline (prior to treatment), 1 hour post-instillation (T1), 1 to 2 weeks after daily use of netarsudil 0.02% (T2), and 1 hour after drop instillation at the 1-to-2-week follow-up (T3). Intraocular pressure (IOP) and blood pressure were measured at each visit.
Main Outcome Measures: Changes in episcleral venous erythrocyte velocity, vessel diameter, and blood flow between time points were analyzed using generalized estimating equation models.
Results: Among the 18 study eyes from 10 enrolled subjects, the baseline IOP was 16.8 ± 3.6 mmHg, which significantly decreased to 13.9 ± 4.2 mmHg at T1, 12.6 ± 4.1 mmHg at T2, and 11.8 ± 4.7 mmHg at T3 (P < 0.05 at each post-treatment time point). The baseline episcleral vessel diameter was 61.3 ± 5.3 μm, which significantly increased at each post-treatment time point (78.0 ± 6.6 μm at T1, 74.0 ± 5.2 μm at T2, and 76.9 ± 6.9 μm at T3, P < 0.05 for all). Baseline AR-13324 episcleral venous flow rates were 0.40 ± 0.22 μL/min, which significantly increased to 0.69 ± 0.45 μL/min at T1 (P = 0.01), remained stable at T2 (0.38 ± 0.30 μL/min), and then increased significantly to 0.54 ± 0.32 μL/min at T3 (P < 0.05 compared to baseline and T2). Conclusions: Netarsudil induces episcleral venous dilation at all measured time points, leading to an increase in episcleral venous flow 1 hour after drop instillation. The resulting increased flow, along with a reduction in episcleral venous pressure, may contribute to a decrease in IOP.