Presentations

Abstract

Introduction:

Minimally invasive glaucoma surgeries (MIGS) aim to reduce intraocular pressure (IOP) by enhancing aqueous humor outflow through implant placement or tissue modification. The Streamline Surgical System is a recent MIGS procedure targeting the natural aqueous humor outflow pathway, designed to lower IOP and mitigate glaucoma progression without implant placement. Comprising a cannula within an outer shell that acts as a pump, it delivers small amounts of viscoelastic fluid into Schlemm's Canal, creating space for aqueous humor outflow. This system is intended for patients with ocular hypertension and open-angle glaucoma and can be used concurrently with other ocular procedures. In this study, our aim is to evaluate the effectiveness of the Streamline Surgical System in reducing IOP, diminishing the number of IOP-lowering drops, and enhancing visual outcomes when combined with cataract extraction in a cohort of patients diagnosed with mild, moderate or severe primary open-angle glaucoma.

Methods:

A retrospective chart review encompassed patients who underwent MIGS with the Streamline Surgical System between 2022 and 2023, with or without concurrent cataract surgery by a single surgeon. Data collection occurred at multiple time points: pre-operatively, 1 day post-operatively, 1 week post-operatively, 1 month post-operatively, 3 months post-operatively, 6 months post-operatively, and 1 year post-operatively. The data included IOP, the number and list of glaucoma medications, Snellen VA distance, Logmar VA distance, spherical equivalent, pre-operative glaucoma stage, glaucoma type, cataract surgery type, and IOL type. The key outcomes of interest were changes from pre-operative to 1-year post-operative measurements in IOP, the number of glaucoma medications, Snellen VA distance, and spherical equivalent.

Results:

All results were analyzed using paired t-tests with a significance level (alpha) set at 0.05. Significant findings include a marked reduction in the number of glaucoma medications used by all patients 6 months post-operatively compared to pre- operatively (p-value: 0.00002). This reduction was also significant in patients with mild glaucoma (p-value: 0.00023) and moderate glaucoma (p-value: 0.03527), while patients with severe glaucoma showed a non-significant decrease (p-value: 0.34344).

A significant decrease in IOP was observed in all patients 6 months post-operatively compared to pre-operatively (p-value: 0.0001). Patients with mild glaucoma (p-value: 0.0068) showed a significant decrease, while those with moderate (p-value: 0.07405) and severe glaucoma (p-value: 0.0555) exhibited non-significant decreases.

Logmar VA Distance also showed significant improvement in all patients 6 months post-operatively compared to pre- operatively (p-value: 0.00097). This improvement was significant in patients with mild glaucoma (p-value: 0.04092) and moderate glaucoma (p-value: 0.02122), while those with severe glaucoma showed a non-significant change (p-value: 0.28638).

Discussion and Conclusions:

In this retrospective chart review, patients with primary open-angle glaucoma, particularly those with mild severity, experienced significant improvements in IOP, the number of glaucoma medications, and Logmar VA distance following Streamline Surgical System intervention. Noted complications included manageable residual inflammation, addressed with eye drops, and transient IOP increases, successfully managed with wound burps to achieve the target IOP. Complications remained minimal and well-controlled at the 6-month mark, with patients reporting enhanced vision. This review is part of a larger ongoing project under the AGE (Advocates for Glaucoma Education) Initiative evaluating the Streamline Surgical System, with further data expected as more patients reach the 1-year post-operative milestone. Future research could focus on case-control comparisons to establish baseline metrics for evaluating the Streamline Surgical System, particularly regarding changes in IOP, Logmar VA distance, medication use, and complications in patients with severe glaucoma. Overall, this review underscores the effectiveness of the Streamline Surgical System in enhancing visual outcomes and reducing medication requirements most notably in mild and moderate open angle glaucoma populations.