- Reference Number: HEY1684/2026
- Departments: Ophthalmology Department
- Last Updated: 28 February 2026
Introduction
This leaflet has been produced to give you general information about your procedure. Most of your questions should be answered by this leaflet. It is not intended to replace the discussion between you and your doctor but may act as a starting point for discussion. If after reading it you have any concerns or require further explanation, please discuss this with a member of the healthcare team caring for you.
What is a Hydrus Microstent
This booklet aims to help you understand the Hydrus implant, which is one way of managing your glaucoma.
The Hydrus microstent is a tiny tube which is implanted in the eye to reduce eye pressure. The procedure is performed at the same time as cataract surgery.
Why do I need a Hydrus Microstent?
Open angle glaucoma and intraocular pressure
Your eyes produce a liquid called aqueous humour, which is essential for healthy eyes. Often in glaucoma this liquid does not flow out of the eye properly and the pressure in your eye increases. This increased pressure can damage your optic nerve.
When you come to clinic we measure your eye pressure. This is important because most people with open angle glaucoma have no early symptoms or eye pain. If left untreated, over time it may result in permanent vision loss and blindness.
The Hydrus
The Hydrus device is made of a tiny tube. It creates a path that allows the fluid inside the eye to bypass the natural drain of the eye, and it is normally only used alongside cataract surgery. It is not visible outside the eye and cannot cause any symptoms. The Hydrus will not cure your glaucoma but will help to slow down any progression.
Cataract surgery with Hydrus
A cataract is a clouding of the lens in the eye that affects vision. Most cataracts are related to ageing. Symptoms of cataracts may include cloudy or blurry vision, colours that seem faded, difficulty with glare
such as sunlight and oncoming headlights, and the need for more frequent change of glasses. Cataract surgery involves the removal of the cloudy natural lens and replacement with an artificial (intraocular) lens.
When you have cataract surgery along with the Hydrus as part of a single operation the Hydrus is implanted in your eye immediately after your cataract is removed and the artificial lens has been implanted.
Can there be any complications or risks?
The risks of the Hydrus and cataract operation are similar to the risks of having cataract operation alone. There are, however, some additional risks associated with Hydrus, and these will be discussed with you before your operation.
There is a small risk that the stent may not be implanted successfully or in the planned position. The stent may become blocked over time and, in rare cases, you may need a second operation to clear the blockage. Quite often microscopic bleeding occurs inside the eye following correct placement, and this tells us that the implantation was successful. It can
cause temporary hazy vision but this will resolve itself.
Although uncommon, there are other risks that may occur such as excessive bleeding during surgery, inflammation and progression of your glaucoma.
General risks of eye surgery include reactions to medicines, infection, inflammation, vision changes, increased eye pressure which are all treatable.
Before your operation
Please read the information leaflet. Share the information it contains with your family (if you wish) so that they can be of help and support.
Your eye will be examined before your operation. Measurements of your eye and eye pressure will determine which type of artificial lens is best for you. Depending on which medications you are taking, you may be asked to stop taking them for few days before your operation or you may be asked to start new medication.
You will have a local anaesthetic in your eye so you will be awake during the operation. You will not be able to see what is happening, but you may be aware of a bright light. There will be some discomfort as the stent is inserted and you may have a dull ache or headache during the surgery as well as couple of days after.
During the operation you will be asked to keep your head still and lie as flat as possible. The whole operation takes approximately 45 minutes.
The surgeon makes a very small cut in the eye, softens the lens with sound waves and removes it through a small tube. The back layer of the lens capsule is left behind. The artificial implant is inserted to replace the cataract. Immediately after the cataract portion of the surgery is completed, the surgeon will implant the Hydrus
After the operation
After the operation, an eye pad or shield will be placed over your eye to protect it. You will spend a short time in the recovery area and then you will be able to go home. It is important that you have someone to take you home as you will not be able to drive. You will be given instructions by the nurses regarding the removal of the eye pad the next day and information about your next appointment. You will also be given an implant card containing important information about the Hydrus. You should keep the card safe. If you need an MRI scan in the future you will need to show the doctor your implant card; although it is made of titanium, the Hydrus implant is considered to be MRI safe.
You will be monitored after your surgery to make sure your eye pressure is controlled. If needed we will recommend additional treatments, including appropriate medication or other treatments to control your eye pressure.
You will be given eye drops to help your eye heal with instructions on how to use them. You may be given some antibiotics to prevent infection. You will usually be examined a month after your surgery to check your eye pressure, which may change during the first several days after surgery. Sometimes a pressure check on day one may be required.
Post-operative instructions
No rubbing or pressing on the eye after the operation. As this can happen when you are sleeping we will ask you to continue wearing the plastic shield at night for a few weeks.
- Reading, watching television and using the computer are fine.
- Do not drive until the doctor tells you it is safe to do so.
- Most people need 1 to 2 weeks off work after the operation.
- To reduce the risk of infection, keep the eye dry for two weeks.
- Please ensure you wear goggles when swimming.
- It is safe to fly after the operation.
Should you require further advice on the issues contained in this leaflet, please do not hesitate to contact the Hull and East Yorkshire Eye Hospital on Tel: 01482 608788
General Advice and Consent
Most of your questions should have been answered by this leaflet, but remember that this is only a starting point for discussion with the healthcare team.
Consent to treatment
Before any doctor, nurse or therapist examines or treats you, they must seek your consent or permission. In order to make a decision, you need to have information from health professionals about the treatment or investigation which is being offered to you. You should always ask them more questions if you do not understand or if you want more information.
The information you receive should be about your condition, the alternatives available to you, and whether it carries risks as well as the benefits. What is important is that your consent is genuine or valid. That means:
- you must be able to give your consent
- you must be given enough information to enable you to make a decision
- you must be acting under your own free will and not under the strong influence of another person
Information about you
We collect and use your information to provide you with care and treatment. As part of your care, information about you will be shared between members of a healthcare team, some of whom you may not meet. Your information may also be used to help train staff, to check the quality of our care, to manage and plan the health service, and to help with research. Wherever possible we use anonymous data.
We may pass on relevant information to other health organisations that provide you with care. All information is treated as strictly confidential and is not given to anyone who does not need it. If you have any concerns please ask your doctor, or the person caring for you.
Under the General Data Protection Regulation and the Data Protection Act 2018 we are responsible for maintaining the confidentiality of any information we hold about you. For further information visit the following page: Confidential Information about You.
If you or your carer needs information about your health and wellbeing and about your care and treatment in a different format, such as large print, braille or audio, due to disability, impairment or sensory loss, please advise a member of staff and this can be arranged.