MINIject surgery

The MINIject® is a 5mm silicone implant designed specifically for patients who have open angle glaucoma.

Glaucoma is a condition where the eye pressure is too high, and causes irreversible damage.

The MINIject implant is soft, flexible, and has anti-scarring, as well as anti-inflammatory, properties. The implant can decrease the pressure inside the eye.

The implant can be fitted either on its own, or during cataract surgery. This means patients have the choice to have both procedures done at the same time, if this is recommended. The implant is inserted into the drainage angle of the eye, and is not visible from the outside.

Benefits of MINIject surgery

The implant is effective at reducing eye pressure, which helps in maintaining your vision. You might be able to use fewer eyedrops in some situations.

MINIject surgery might be recommended if:

  • other treatments, such as eyedrops or laser surgery have not worked
  • you are having problems using eye drops
  • you are intolerant to eye drops

Risks of MINIject surgery

It is normal for there to be some bleeding inside the eye during the procedure. This usually resolves within a few days.

There is a small chance that the implant could become blocked, or move. Surgery may be needed to remove the implant, if it is not in the correct position. However, this is extremely unlikely.

The implant’s effect on lowering eye pressure may not last, or it may gradually fade. If this happens, you might need to restart your glaucoma treatments or have more procedures. 

Risks with cataract surgery

There are additional risks associated with cataract surgery, and it is important that you are aware of these. 

Read our information about cataract surgery.

Other treatment options

There are other treatments available. This will depend on the type of glaucoma you have, and how severe it is.  It will also depend on your general health and the type of treatment you prefer. The recommended course of treatment for you will be guided by your eye specialist.

We want to involve you in decisions about your care and treatment. If you decide to go ahead, you will be asked to sign a consent form. This states that you understand what the treatment involves, and you agree to have it.  

Read more about our consent process

Preparing for surgery

A few weeks before the procedure, you will be given a pre-assessment appointment. This is where you will be given instructions on what to eat and drink. You can also ask any questions you may have.  

Changes to your medicines

You might need to make some changes to your medicine before surgery.

You should let us know if you:

  • are taking any blood-thinners, such as antiplatelet medicines (for example aspirin or clopidogrel) or anticoagulant medicines (for example warfarin or rivaroxaban). As you might need to stop them temporarily before your surgery
  • have diabetes, as you might need to change the dose (amount) of your diabetes medicines
  • are taking any regular medicines (including anything you buy from a pharmacy or shop, and any herbal or homeopathic medicines)
  • have any allergies to any medicines

More information on stopping medicines will be given to you at your pre-assessment appointment.

On the morning of the procedure, you should use your eye drops as you usually would, unless your doctor has told you not to.

During the procedure

The treatment is usually done under local anaesthetic. An injection will be given around the eye to numb the area.

The surgery will usually last 10 to 15 minutes. If you also having cataract surgery, this will be longer.

Pain during surgery

As local anaesthetic will be used, you might feel a slight squeeze or pressure, but you should not have any pain during the operation. It is a very safe and effective method of relieving pain during eye surgery. You may have some discomfort or numbness around the eye after the surgery, but this will eventually fade as the medicine wears off.

Your doctor will make sure that you are relaxed and comfortable throughout your treatment. However, if you think that you might need a different type of anaesthetic, you should consult with your doctor before the day of your operation. 

You can read our information about different types of anaesthetic

After surgery

After your surgery, your eye will be covered with a patch. This can usually be removed the next day. You should not be in much pain after surgery, but you can take regular painkillers if you need to.

Patients are usually allowed to leave the hospital a few hours after the surgery and can eat and drink when they want to. Rarely, doctors might ask patients to stay in the recovery room for further checks before they can leave the hospital.

The nursing team in the recovery area will tell you when you can remove your dressing, and they will show you how to do this.

The implant should begin lowering your eye pressure immediately. However, some glaucoma treatment may still be needed in the operated eye. Your doctor will tell you if this is needed.

Any drops used in your other eye must continue to be used as usual.

The MINIject implant is compatible with MRI, so you can still have an MRI if you need one in the future.

Returning to your normal activities

For the first month after surgery, avoid swimming, tennis, running, and any contact sports. 

Most people take 1 to 2 weeks off work after surgery. However, this will depend on your individual circumstances and the type of work you do.

It is safe to go on holiday after surgery. However, you will need to see your surgeon frequently in the first month after your procedure. This is so your surgeon can see if your pressure-lowering medicines need to be reduced or stopped.

Go to the eye department or visit your nearest emergency department (A&E) if:

  • you notice any loss in vision
  • you notice worsening redness in your eyes
  • you have a lot of pain
  • you notice worsening sensitivity to light

Follow-up appointments

Outcomes from MINIject surgery vary based on the type of glaucoma you have, and how severe it is. We will constantly evaluate your progress in the weeks and months after the surgery. Before you leave the hospital, you will be given a follow-up appointment.

It is important to remember that while this operation can help you manage your glaucoma, it is not a cure. You may still need eye drops, other glaucoma treatments, or surgery, in the future if your pressure rises over time. Having MINIject surgery will not prevent you from being able to have further procedures, if these are needed. 

Resource number: 5466/VER1
Last reviewed: January 2024 
Next review: January 2027

Contact us

If need urgent advice, or have any symptoms you are concerned about, please contact eye casualty

Phone: 020 7188 4336, Monday to Friday, 9am to 4pm

Out of hours, please go to the emergency department (A&E) where an eye doctor will be called to see you.

For non-urgent queries, please call the glaucoma call-back service.

Phone: 020 7188 9121, Monday to Friday, 9am to 5pm. Leave your name, phone number and a brief message. You will be contacted within 48 hours (Monday to Friday only) excluding public holidays.

Do you have any comments or concerns about your care?

Contact our Patient Advice and Liaison Service (PALS)

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