Hydrus Microstent for Glaucoma
What Is the Hydrus Microstent?
The Hydrus Microstent is a type of minimally invasive glaucoma surgery (MIGS) device, meaning it works through small incisions and causes less disruption to the eye than traditional glaucoma surgeries. It is a permanently implanted scaffold placed inside a natural drainage channel in your eye to improve fluid outflow and reduce pressure. Understanding how the device works can help you feel confident going into your consultation.
Glaucoma is often caused or worsened by elevated intraocular pressure, which is the pressure inside the eye. This pressure builds when fluid cannot drain properly through a channel called Schlemm's canal. The Hydrus Microstent holds this canal open, allowing fluid to flow out of the eye more freely and consistently. Unlike daily eye drops that rely on you remembering to apply them, the stent works continuously once it is in place, which may help reduce how many drops you need each day.
The Hydrus Microstent is a curved, flexible tube roughly 8 millimeters long, made from a biocompatible material that your body tolerates well. It is designed to span a significant portion of Schlemm's canal, which may improve drainage over a wider area compared to some smaller stent options.
- The stent is placed through a tiny opening in the trabecular meshwork, the tissue that normally filters fluid out of the eye
- It sits inside the drainage structures of the eye, completely out of your line of sight
- You will not see or feel the device after it is in place
- The implant is permanent and designed to remain in your eye long-term
Several MIGS devices exist, each working slightly differently. The Hydrus Microstent is longer than some alternatives, such as the iStent family, and supports a greater length of the drainage canal. For patients who need more aggressive pressure reduction, traditional filtering surgeries like trabeculectomy or tube shunt implants remain an option, and Dr. Anis is experienced with the full range of glaucoma surgical procedures. The right choice depends on your anatomy, the severity of your glaucoma, your target pressure, and whether you are also having cataract surgery.
Who May Be a Good Candidate?
The Hydrus Microstent is most commonly recommended for adults with mild to moderate primary open-angle glaucoma, which is the most common form of the disease. It is approved in the United States for use at the same time as cataract surgery. Determining whether you are a good candidate requires a thorough evaluation of your eye anatomy, pressure history, and overall treatment goals.
If your current treatment is not keeping your eye pressure in a safe range, it may be time to consider surgical options. There are several patterns we watch for that suggest your glaucoma may need a different approach.
- Eye pressure consistently above your target range across multiple visits
- Progressive optic nerve damage seen on imaging or visual field testing
- Difficulty controlling pressure even with the maximum medications you can tolerate
- Side effects from glaucoma drops that make them hard or impossible to use
- Challenges with daily drop routines due to cost, access, or physical limitations
You should never adjust or stop glaucoma medications on your own without speaking to your Eye Doctor first. Uncontrolled pressure can lead to permanent vision loss, so any concerns about your current regimen should be addressed promptly.
Many patients with glaucoma also develop cataracts, which is the clouding of the eye's natural lens. When both conditions are present, combining cataract removal with Hydrus Microstent placement can address both problems at once, reducing the number of separate surgeries you need. Dr. Anis performs combined cataract-glaucoma procedures and can discuss whether premium intraocular lens options are appropriate for your individual situation.
Not every patient or every type of glaucoma is suited for this device. A careful evaluation of your drainage angle anatomy and overall eye health is essential before recommending it.
- Angle-closure glaucoma, where the drainage angle is narrow or closed
- Neovascular glaucoma, often associated with diabetic eye disease
- Uveitic or inflammatory glaucoma, or a recent history of significant eye inflammation
- Significant scarring, prior angle surgery, or altered drainage structures
- Severe or end-stage glaucoma requiring more aggressive pressure reduction than MIGS can provide
- Active infection or inflammation inside the eye
If the Hydrus Microstent is not the right fit, Dr. Anis will discuss alternative procedures that better match your specific needs.
What to Expect During the Procedure
The procedure itself is carefully planned and performed in a surgical setting, typically as an outpatient experience. Most patients are surprised by how straightforward the process is when the Hydrus Microstent is combined with cataract surgery. Knowing what to expect ahead of time can ease any anxiety you may have about the day.
Before your procedure, we perform a comprehensive eye examination that includes measuring your eye pressure, evaluating your optic nerve with optical coherence tomography (OCT), reviewing your visual field results, and examining your drainage angle with a special contact lens called a goniolens. These steps confirm that your anatomy is appropriate for the Hydrus Microstent and help Dr. Anis plan the most precise approach. If you are also having cataract surgery, we will take detailed measurements of your eye to select the correct intraocular lens power for the best vision outcome.
The procedure is done under local anesthesia, so you will be awake but comfortable and should not feel pain. A microscope is used throughout to give a magnified, detailed view of the surgical site.
- A small incision is made in the clear front part of the eye, called the cornea
- The Hydrus Microstent is guided into position inside Schlemm's canal using a specialized delivery tool
- Once properly positioned, the device is released and the delivery tool is removed
- The incision typically seals on its own without sutures
If cataract surgery is being performed at the same time, the cloudy natural lens is removed and replaced with an intraocular lens either before or after the stent is placed, depending on the surgical plan.
When the Hydrus Microstent is placed alongside cataract surgery, the combined procedure typically takes about 15 to 30 minutes. Adding the stent extends the operation by only a few minutes. You will spend additional time at the surgical facility before and after the procedure for preparation, anesthesia, and initial monitoring, so plan to be there for a few hours in total. You will need someone to drive you home, and you should arrange for help at home for at least the first day.
Recovery and Aftercare
Most patients recover well from the Hydrus Microstent procedure, especially when it is combined with cataract surgery. The recovery period involves some temporary discomfort, a structured medication schedule, and several follow-up visits to monitor your healing and pressure. Following your aftercare instructions closely is one of the most important things you can do to protect your results.
Right after surgery, your vision will likely be blurry, and your eye may feel scratchy or gritty. A small amount of blood in the front of the eye, called a microhyphema, is common and can temporarily add to the blurriness. This usually clears within a few days and is monitored at your first follow-up visit. Mild redness and swelling around the eye are also normal and typically improve within the first week.
We will prescribe antibiotic and anti-inflammatory eye drops to reduce the risk of infection and control swelling. These must be used exactly as directed, even if your eye feels fine, because stopping too early can lead to complications.
- Anti-inflammatory or steroid drops are typically used and gradually reduced over several weeks
- Antibiotic drops are generally continued for one to two weeks
- Depending on your pressure response, you may still need some glaucoma medications
- Your drop regimen may change quickly based on your pressure readings, so always check with your Eye Doctor before making any adjustments
To protect your eye while it heals, you will need to limit certain activities for at least one to two weeks. Heavy lifting, bending over, and strenuous exercise can raise eye pressure and stress healing tissues. You should also avoid rubbing your eye, swimming, and environments with dust or debris. Wearing the protective eye shield we provide at night helps prevent accidental contact while you sleep.
We will see you within the first day or two after surgery, then again around one week, and several more times over the following months. These visits allow us to confirm that the stent is functioning properly and that your pressure is within a healthy range. We may adjust your medications based on these pressure readings and the overall appearance of your eye as it heals.
While serious complications are uncommon, certain symptoms should never be ignored. Contact our office right away if you notice any of the following, and go to an emergency facility if symptoms are severe or rapidly worsening.
- Sudden or severe eye pain that does not respond to over-the-counter pain relievers
- A noticeable decrease in vision, or new flashes of light and floaters
- Worsening redness, discharge, or swelling rather than gradual improvement
- Nausea or vomiting along with eye pain, which can signal dangerously high pressure
- Increasing sensitivity to light or severe headache with halos around lights
- Fever or unusual discharge, which may indicate infection
- Any direct trauma or injury to the eye after surgery
Results, Risks, and Long-Term Outlook
The Hydrus Microstent is a long-term tool for managing glaucoma, not a cure. The primary goal is to lower eye pressure and potentially reduce the number of medications you need. Because glaucoma is a lifelong condition, ongoing monitoring remains essential even after a successful procedure, and your treatment plan may need to evolve over time.
When combined with cataract surgery, the Hydrus Microstent typically provides meaningful additional lowering of eye pressure. The exact amount varies based on your starting pressure, your eye anatomy, and the severity of your glaucoma. It is worth noting that cataract surgery alone can lower eye pressure in some patients, so outcomes reflect the combined effect of both procedures. The goal is to bring your pressure to a range that slows or stops further damage to the optic nerve and preserves your remaining vision.
Some patients are able to reduce the number of glaucoma medications they use after receiving a Hydrus Microstent, and some may be able to stop drops altogether if their pressure stays low enough on its own. However, many people continue to need at least one medication. Using fewer medications can meaningfully improve daily life by reducing side effects, simplifying routines, and lowering costs. We will monitor your pressure closely and make adjustments to your plan as needed over time.
As with any eye surgery, there are potential risks, though serious complications are uncommon, particularly when the procedure is performed by an experienced surgeon. Many early issues are temporary and resolve with appropriate monitoring and treatment.
- Small amounts of bleeding in the front of the eye in the first few days, typically minor and self-resolving
- Temporary spikes or fluctuations in eye pressure shortly after surgery
- Inflammation inside the eye, managed with anti-inflammatory drops
- Corneal swelling or blurred vision early in recovery
- Iris adhesions, called peripheral anterior synechiae, that can reduce drainage effectiveness over time
- Device malposition or partial blockage that may require additional treatment
- Less commonly, the need for additional laser treatment or a separate surgical procedure
The Hydrus Microstent is made from durable materials intended to remain in your eye permanently. However, its effectiveness in lowering pressure can decrease over time as scar tissue forms, as other parts of the drainage system become less efficient, or as glaucoma progresses. This is why regular monitoring is so important even years after your procedure. If your pressure rises again, there are additional treatment options available, and catching changes early gives us the best chance to respond effectively.
Frequently Asked Questions
These are some of the questions patients most commonly ask when considering the Hydrus Microstent. If you have concerns that are not addressed here, we are happy to discuss them at your consultation.
In rare situations, the device can potentially be removed through a separate surgical procedure, though this is uncommon. Most issues that arise after placement can be managed using medications, laser treatment, or other interventions without removing the stent. If a problem does develop, Dr. Anis will discuss all available options and guide you toward the safest course of action.
The Hydrus Microstent is generally classified as MR-conditional, meaning it may be compatible with MRI under specific conditions outlined by the manufacturer. Before any MRI scan, you should inform the imaging facility that you have an implanted eye device. Our office can provide the necessary implant details for the radiology team to confirm compatibility and determine the appropriate scanning parameters.
Coverage depends on your specific insurance plan, the medical necessity documentation supporting your case, and whether the procedure meets your plan's criteria for minimally invasive glaucoma surgery. Prior authorization is often required. We recommend contacting your insurer before scheduling to understand your expected out-of-pocket costs, and our team can assist with documentation to support the authorization process.
Trabeculectomy is a more invasive filtering surgery that creates a new drainage opening in the eye and can achieve greater pressure reduction than the Hydrus Microstent. It is generally reserved for more advanced glaucoma or cases where less invasive options have not been sufficient, because it carries a higher risk of complications. The Hydrus Microstent is better suited for mild to moderate disease, particularly when glaucoma is being addressed alongside cataract surgery, while trabeculectomy remains an important option when more aggressive pressure control is needed.
If your pressure does not reach a safe target after the procedure, we have additional options available. These may include restarting or adjusting glaucoma medications, adding laser treatment such as selective laser trabeculoplasty (SLT), or planning a more advanced surgical procedure if needed. The Hydrus Microstent is one step in managing a lifelong condition, and having it does not limit your access to other treatments in the future.
Yes, it is important to let all your health care providers know you have an ocular implant. This is especially relevant before any imaging procedure such as an MRI, and it is helpful context for any provider who may be treating your eye or a condition related to eye pressure. We will provide you with implant documentation after your surgery to keep with your medical records.
Talk to Our Glaucoma Specialists About the Hydrus Microstent
If you have glaucoma and are wondering whether the Hydrus Microstent could be part of your care plan, Rhode Island Eye Institute is here to help you find answers. Dr. Sarah Anis brings fellowship-level training and extensive surgical experience to every patient consultation, offering individualized guidance grounded in the most current evidence. We serve patients throughout Rhode Island and southeastern Massachusetts, and we welcome the opportunity to review your history, evaluate your eye health, and discuss every option available to protect your vision for the long term.