The STREAMLINE Surgical System (New World Medical, California, USA) is a minimally invasive glaucoma surgery (MIGS) device targeting the trabecular meshwork (TM) and Schlemm’s canal (SC)1)2).
Minimally invasive glaucoma surgery causes less tissue damage and allows earlier visual recovery compared to traditional trabeculectomy or tube shunt surgery4)5). Among MIGS procedures, this device is classified as “trabecular viscodilation” and belongs to the same category as ABiC (ab interno canaloplasty) and the OMNI Surgical System1)4).
This device does not use an implant and has two functions: injection of viscoelastic material into Schlemm’s canal and localized goniotomy. It has two indications: FDA 510(k) clearance for intraocular injection of viscoelastic fluid and a Class I exemption for incising trabecular tissue.
QWhat kind of minimally invasive glaucoma surgery is the Streamline Surgical System?
A
It is a minimally invasive glaucoma surgery device that simultaneously performs transluminal viscoelastic dilation of Schlemm’s canal and localized incision of the trabecular meshwork. Since no implant is placed, there is no risk of foreign body-related complications. Unlike ABiC or OMNI in the same category, which require 360-degree catheter passage, this device is characterized by treatment through localized punctures at multiple sites. It is indicated for ocular hypertension and open-angle glaucoma, and can be performed alone or in combination with cataract surgery1)2).
4. Surgical Technique and Postoperative Management
It is a disposable device with a stainless steel cannula housed inside an outer sleeve. When the actuator button is pressed, a pump activates, the outer sleeve retracts, the cannula is exposed, and viscoelastic material is injected. Each press delivers approximately 7 microliters, and up to 8 injections are possible.
Puncture Technique: Bring the outer sleeve close to the anterior trabecular meshwork and press the actuator button for 2 seconds. The cannula is positioned in Schlemm’s canal and viscoelastic material is injected3).
Treatment Range and Postoperative Management
Treatment Range: Puncture at least 3 sites over at least 3 clock hours (90 degrees). Up to 8 bolus injections are possible.
Reflux Bleeding: Reflux bleeding from the treatment site may be observed, indicating access to Schlemm’s canal.
Viscoelastic Removal: After the procedure, remove the viscoelastic material in the usual manner and close the wound.
Postoperative eye drops: A combination of prednisolone and antibiotics is tapered over 4 weeks3)
When combined with cataract surgery, the device is inserted through the same corneal incision after lens reconstruction3).
Contraindications include cases where visualization of the anterior chamber angle is difficult, patient cooperation cannot be obtained, or consent for surgery is not given.
A prospective study of 37 eyes with mild to moderate primary open-angle glaucoma undergoing combined cataract surgery reported the following outcomes3).
Parameter
Preoperative
12 Months
Mean intraocular pressure
23.2 mmHg
16.2 mmHg
Mean number of medications
2.1
0.8
Medication-free rate
—
51.4%
Intraocular pressure was significantly reduced at all postoperative time points (p<0.0001)3). At 12 months, 80% of eyes achieved a ≥20% reduction in IOP from baseline, and 48.6% showed a ≥30% reduction3). Medication use decreased by 60.5% at 12 months, and 71.4% of eyes were on fewer medications than before surgery3).
No adverse events attributable to the device or the transluminal dilation procedure were reported3). The only adverse event observed in multiple eyes was elevated IOP (4 eyes), all of which resolved with short-term topical medication3). Corneal endothelial cell density decreased by 16.8% at 12 months but stabilized after 3 months, comparable to that reported with cataract surgery alone3).
Comparison with other minimally invasive glaucoma surgeries
Minimally invasive glaucoma surgery encompasses a variety of devices, and currently no large-scale prospective or retrospective trials of the Streamline Surgical System are available4). However, existing data suggest outcomes comparable or superior to other trabecular bypass devices and transluminal dilation procedures3).
Minimally invasive glaucoma surgery generally results in a 15–50% reduction in IOP and a decrease of 0.4–1.8 medications5). Combined with cataract surgery, additional IOP reduction (2–2.8 mmHg) and lower reoperation rates (3% vs 24% at 2 years) have been reported compared to MIGS alone5).
QWhat is the difference between the Streamline Surgical System and other minimally invasive glaucoma surgeries?
A
ABiC, a viscoelastic dilation procedure in the same category, uses a microcatheter to pass through the entire circumference (360 degrees) of Schlemm’s canal and inject viscoelastic material2). OMNI uses a flexible microcatheter to perform two 180-degree passes, enabling both viscoelastic dilation and trabeculotomy2)4). Streamline differs by injecting viscoelastic material through localized punctures at multiple sites rather than passing a catheter around the entire circumference. All share the common feature of not requiring implant placement.
In glaucomatous eyes, the trabecular meshwork is the main site of resistance to aqueous humor outflow, and additional outflow resistance exists in Schlemm’s canal and the collector channels 3).
The mechanism of action of the Streamline Surgical System is two-step. First, puncturing the trabecular meshwork directly reduces resistance at the trabecular meshwork-inner wall of Schlemm’s canal. Second, injecting viscoelastic material into Schlemm’s canal dilates the lumen, opening the collector channel ostia and reducing resistance in the distal outflow pathway.
This action allows aqueous humor to pass more efficiently through the physiological outflow pathway—Schlemm’s canal, collector channels, aqueous veins, and episcleral veins—thereby lowering intraocular pressure.
IOP Lowering Limits of Minimally Invasive Glaucoma Surgery
The intraocular pressure (IOP)-lowering effect of minimally invasive glaucoma surgery targeting the trabecular meshwork/Schlemm’s canal is limited by distal outflow resistance and episcleral venous pressure 2). Therefore, the minimum achievable IOP is near the episcleral venous pressure (typically 8–10 mmHg). Mild to moderate open-angle glaucoma is the main indication; for severe cases requiring substantial IOP reduction, bleb-forming surgery is recommended 1).
QWhy is canalicular viscoelastic dilation effective?
A
In glaucomatous eyes, in addition to increased trabecular outflow resistance, collapse of Schlemm’s canal and narrowing of collector channel ostia contribute to outflow obstruction. Injecting viscoelastic material into Schlemm’s canal to physically dilate the lumen improves aqueous access to the collector channels and distal outflow pathways. This provides additional IOP lowering beyond that achieved by trabecular incision alone. The Streamline system simultaneously achieves both trabecular incision and viscoelastic dilation at the local puncture site.
The Streamline Surgical System is a relatively new device, and the following studies are ongoing.
A prospective, non-randomized, open-label trial (NCT05089474) is ongoing, accumulating further data on efficacy and safety.
Combined with cataract surgery, a 30.2% IOP reduction and 51.4% medication-free rate at 12 months have been reported 3).
Standardization efforts for reporting clinical endpoints in minimally invasive glaucoma surgery are progressing, which is expected to enable more accurate comparisons between devices 4).
Future challenges include the following:
Conducting large-scale RCTs
Evaluating efficacy as a standalone surgery
Accumulation of long-term (5 years or more) outcome data
Direct comparative trials with other minimally invasive glaucoma surgeries (OMNI, ABiC)
Standardization of optimal number of puncture sites and viscoelastic injection volume
QIs the Streamline Surgical System available in Japan?
A
The Streamline Surgical System has received FDA 510(k) clearance in the United States, but as of 2024, it has not obtained pharmaceutical approval in Japan. Similar minimally invasive glaucoma surgeries available in Japan include microhook trabeculotomy and iStent inject W. Depending on future accumulation of clinical data and regulatory evaluation, the possibility of use in Japan and other countries may expand.
European Glaucoma Society. Terminology and Guidelines for Glaucoma, 6th Edition. Br J Ophthalmol. 2025.
American Academy of Ophthalmology. Primary Open-Angle Glaucoma Preferred Practice Pattern®. 2020.
Lazcano-Gomez G, Antzoulatos GL, Kahook MY. Combined Phacoemulsification and STREAMLINE Surgical System Canal of Schlemm Transluminal Dilation in Eyes of Hispanic Patients with Mild to Moderate Glaucoma. Clin Ophthalmol. 2023;17:1911-1918.
Fellman RL, Mattox CG, Ross C, et al. Reporting Clinical Endpoints in Studies of Minimally Invasive Glaucoma Surgery. Ophthalmology. 2025;132(2):141-159.
Singh P, Sharma B, Sarma N, et al. Clinical Outcomes and Patient-Reported Outcomes of Minimally Invasive Glaucoma Surgery Techniques Over the Past Decade. Cureus. 2025;17(7):e87872.
Copy the article text and paste it into your preferred AI assistant.
Article copied to clipboard
Open an AI assistant below and paste the copied text into the chat box.
