Early Clinical Experience with the Novel A-Stream Glaucoma Shunt Combined with Mid-Posterior Tenon’s Capsule Advancement Flap

Q: What was the primary aim of the study?

To evaluate clinical outcomes and surgical techniques of A-stream Glaucoma Shunt implantation.

Q: How were the eyes divided into study groups?

Group A left the distal tip of the ripcord exposed and covered the device with MPTAF and related coverings, while group B reshaped the ripcord into a loop at the corneal limbus and covered the device with MPTAF.

Q: What defined “success” in the study?

An IOP ≤ 21 mmHg with at least 20% reduction from baseline, without clinically significant hypotony, and no reoperation for glaucoma.

Sep 30, 2026

Uploaded by nayy☆

Study objective was to assess clinical outcomes and surgical techniques for A-stream Glaucoma Shunt (A-stream; MICROT Inc.) implantation. A retrospective review analyzed 59 eyes from 59 patients, divided into group A and group B based on ripcord exposure and coverage with mid-posterior Tenon’s capsule advancement flap (MPTAF). Outcomes included intraocular pressure, medication count, visual acuity, and postoperative complications. At 6 months, both groups showed significant IOP reduction with defined success criteria.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages12

Reading Time30 min

AccessFree to download

Abstract

1. Introduction

2. Materials and Methods

2.1. Participants

2.2. Surgical Technique

Article Early Clinical Experience with the Novel A-Stream Glaucoma Shunt Combined with Mid-Posterior Tenon’s Capsule Advancement Flap Young Hoon Hwang , Sharon Lee, Mijin Kim and Jaewan Choi * Academic Editor: Vincenzo Parisi Received: 23 November 2025 Revised: 16 December 2025 Accepted: 19 December 2025 Published: 21 December 2025 Copyright: © 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license. Central Seoul Eye Center, Seoul 04427, Republic of Korea; [brainh@hanmail.net](brainh@hanmail.net) (Y.H.H.); [lsr6882@nate.com](lsr6882@nate.com) (S.L.); [happypinnk52@gmail.com](happypinnk52@gmail.com) (M.K.) * Correspondence: [deskshot@naver.com](deskshot@naver.com) Abstract Objectives: The aim of this study was to evaluate the clinical outcomes and surgical techniques of A-stream Glaucoma Shunt (A-stream; MICROT Inc.) implantation. Methods: A retrospective review of 59 eyes from 59 patients who underwent A-stream implantation was conducted. Eyes were divided into two groups: group A (25 eyes), where the distal tip of the ripcord was left exposed and the device was covered with conjunctiva, scleral flap, pericardium patch graft, or mid-posterior Tenon’s capsule advancement flap (MPTAF); and group B (34 eyes), where the ripcord was shaped into a loop at the corneal limbus and the device was covered with MPTAF. Intraocular pressure (IOP), number of IOP-lowering medications, visual acuity, and postoperative complications were analyzed. Success was defined as an IOP ≤ 21 mmHg with ≥20% reduction from baseline, without clinically significant hypotony, and no reoperation for glaucoma. Results: At 6 months, the mean IOP decreased significantly in both groups (group A: 27.4 ± 9.8 mmHg to 15.2 ± 5.1 mmHg; group B: 25.1 ± 11.6 mmHg to 14.0 ± 7.0 mmHg, p < 0.001) . Success rates were 76.0% in group A and 88.2% in group B (p = 0.207) . Early postoperative hypotony occurred in 8.0% of group A and 14.7% of group B, and these cases resolved without further intervention within 1 month. Ripcord complications were observed in 28.0% of group A, but none in group B. Conclusions: A-stream implantation with MPTAF and a limbal ripcord loop is an effective and safe procedure with minimal risk of device exposure and ripcord-related complications. Keywords: glaucoma; surgery; intraocular pressure 1. Introduction A-stream Glaucoma Shunt (A-stream; MICROT Inc., Seoul, Republic of Korea) is a recently introduced minimally invasive glaucoma drainage device (GDD) designed to divert aqueous humor from the anterior chamber to the post-limbal sub-Tenon’s space [1] . The device consists of a 6 mm tube with an internal diameter of 100 µm that serves as the pathway for aqueous outflow, a wing attached to the tube to prevent anterior migration, and a pre-placed 7-0 nylon intraluminal thread that limits excessive aqueous drainage [1] . In addition, this intraluminal thread serves another role by enabling stepwise postoperative flow control through partial or complete removal, and is therefore commonly referred to asa “ripcord.” The concept of a tube with a pre-placed removable intraluminal ripcord has been applied either to membrane–tube type GDDs [2] . Previous laboratory and clinical studies using a tube with a profile similar to that of A-stream have demonstrated stable and predictable aqueous drainage [2,3] . To date, the only formally reported technique of A-stream implantation involves conjunctival incision, scleral flap formation, tube insertion under the scleral flap, and placement of the extraocular portion of the ripcord through the conjunctival surface over the bleb [1] . We considered that, while maintaining the fundamental concept of A-stream implantation, alternative surgical approaches could be applied. In this study, we sought to investigate such options, particularly with respect to de

FAQs

What was the primary aim of the study?

To evaluate clinical outcomes and surgical techniques of A-stream Glaucoma Shunt implantation.

How were the eyes divided into study groups?

Group A left the distal tip of the ripcord exposed and covered the device with MPTAF and related coverings, while group B reshaped the ripcord into a loop at the corneal limbus and covered the device with MPTAF.

What defined “success” in the study?

An IOP ≤ 21 mmHg with at least 20% reduction from baseline, without clinically significant hypotony, and no reoperation for glaucoma.

Sep 30, 2026

Uploaded by nayy☆