Objectives: This study aimed to compare surgically induced corneal astigmatism (SIA) between Baerveldt glaucoma implant (BGI) surgery and trabeculectomy and to identify prognostic factors associated with SIA. Methods: This retrospective cohort study included 109 and 229 eyes that underwent BGI surgery and trabeculectomy, respectively, at Fukui University Hospital. Corneal astigmatism was assessed preoperatively, and at 6 months postoperatively, the mean SIA (M-SIA) and centroid SIA were calculated, and factors associated with M-SIA were determined. Results: BGI surgery was associated with greater SIA than trabeculectomy. Postoperative corneal astigmatism was −1.53 ± 1.01 D in the BGI group and −1.33 ± 0.92 D in the trabeculectomy group (p = 0.044). The M-SIA was significantly larger in the BGI group (1.41 ± 1.05 D vs. 0.94 ± 0.74 D, p < 0.01). Multivariate regression revealed that BGI surgery and lower preoperative corneal astigmatism were independently associated with greater M-SIA. Subgroup analysis revealed that older age and lower preoperative astigmatism were significant predictors of larger M-SIA in the BGI group, whereas only preoperative astigmatism was significant in the trabeculectomy group. Conclusions: BGI surgery was associated with greater and more variable SIA than trabeculectomy. Surgical type, baseline astigmatism, and age are important predictors of postoperative SIA.

Background/Objectives: Rho-associated protein kinase inhibitors reduce intraocular pressure (IOP) by enhancing aqueous humor outflow through the trabecular meshwork–Schlemm’s canal pathway. However, it remains unclear whether the fixed-dose combination of ripasudil hydrochloride hydrate and brimonidine tartrate (GLAALPHA) enhances conventional aqueous outflow in vivo. Methods: This single-center randomized clinical trial included healthy adult volunteers who received GLAALPHA, a brimonidine tartrate–brinzolamide fixed-dose combination (Ailamide), or brimonidine tartrate monotherapy (Aiphagan) in a crossover sequence. The aqueous column width in the episcleral veins was assessed at baseline and at 2 h (primary outcome) and 8 h using hemoglobin video imaging. Results: Among 24 participants, analyses included 23 GLAALPHA-treated eyes, 21 Ailamide-treated eyes, and 22 Aiphagan-treated eyes. Two hours after instillation, the aqueous column width significantly increased from baseline only in the GLAALPHA group (p = 0.002). The percent increase in the aqueous column width at 2 h was significantly greater with GLAALPHA than with Ailamide (p = 0.039) and not significantly different between GLAALPHA and Aiphagan (p = 0.114). At 8 h, the aqueous column width did not differ from the baseline in any groups. Conclusions: In healthy adult eyes, GLAALPHA significantly increased the aqueous column width in the episcleral veins 2 h after instillation, indicating enhanced conventional aqueous outflow. These findings provide evidence that GLAALPHA promotes trabecular outflow beyond the effects of brimonidine tartrate-containing comparators and offer mechanistic insights into its action.