Treatment aims to reduce the pressure in the affected eye, called intraocular pressure.
Any damage to your vision caused by glaucoma can't be repaired so it's important to get an early diagnosis and treatment to prevent further damage.
Chronic open-angle glaucoma is often treated using eye drops. There are several different types of eye drops available, the type prescribed may depend on:
- how your condition is progressing
- whether you have other medical conditions
- whether you are taking any other medications
- whether the eye drops cause side effects when you use them
Using eye drops
It's important to use eye drops as directed. Even if you have not yet noticed any problems with your vision, without treatment glaucoma can cause permanent vision loss.
To use eye drops:
- use your finger to gently pull down your lower eyelid
- hold the bottle over your eye and allow a single drop to fall into the pocket you have created in your lower lid
- close your eye and keep it closed for several minutes
If you are using two different types of eye drops, allow at least five to 10 minutes between using the different types.
If you usually wear contact lenses and have been prescribed eye drops, you may need to stop wearing your lenses and wear glasses instead.
This is because medication in the eye drops can build up in the lenses and may harm your eyes. You should discuss this with healthcare professionals treating you.
Types of eye drops
The different types of eye drops are described below. You can read medicines information for more details about your medication.
Prostaglandin analogues increase the flow of fluid (aqueous humour) out of your eye, which reduces the pressure within your eye (the intraocular pressure). These eye drops are usually used once a day.
Side effects include:
- enlarged blood vessels in the white part of your eye, making your eye look red
- changes to your eye colour – it often gets darker
- eyelashes growing thicker and darker
- eye pain and irritation
- blepharitis – where the rims of your eyelids become red and swollen
- dry eyes
- sensitivity to light
Some types of prostaglandin analogues that you may be prescribed include:
It is thought that beta-blockers reduce intraocular pressure by slowing down the production of aqueous humour in your eye. They are used once or twice a day and can cause side effects such as:
- a stinging or burning sensation in your eye
- dry eyes
- itchy eyes
Beta-blockers can worsen some medical conditions :
Some types of beta-blockers you may be prescribed include:
Carbonic anhydrase inhibitors
Carbonic anhydrase inhibitors reduce the amount of aqueous humour produced in your eye, which reduces intraocular pressure. These drops are used two or three times a day and may cause:
- a bitter taste in your mouth
- nausea (feeling sick)
- a dry mouth
- eye irritation
Some types of carbonic anhydrase inhibitors you may be prescribed include:
Sympathomimetics are thought to reduce the rate of production of aqueous humour and increase the flow of aqueous humour out of the eyes. These eye drops are used twice a day and may cause your eyes to become painful and red.
Some types of sympathomimetics can only be used with caution in people who have:
A type of sympathomimetic that you may be prescribed is brimonidine tartrate.
If the use of eye drops does not improve your symptoms, a different type of treatment may be recommended, such as laser treatment or surgery. These are described in more detail below.
Laser treatment (Selective Laser Trabeculoplasty)
Laser treatment, which uses high energy beams of light, can be used to open up the blocked trabecular meshwork (drainage tubes) within your eye. This is called laser trabeculoplasty.
Anaesthetic (painkilling) eye drops will be put into your eye and a special lens placed in front of your eye. The laser will be shone through the lens and will make small holes in the trabecular meshwork. This allows more fluid to drain out of your eye and reduces the intraocular pressure.
Laser treatments are usually quick and painless, although during the procedure you may feel a brief twinge of pain or heat. You may still need to use eye drops (see above) after having laser treatment.
A trabeculectomy is the most common type of glaucoma surgery. It involves removing part of the trabecular meshwork to allow fluid to flow through the eye's drainage system.
If you are having surgery, we may choose to use anti-scarring medicines. These can improve the success of the operation by preventing scar tissue forming as your eye heals.
You may be prescribed either:
- mitomycin C
These medications are unlicensed for the treatment of glaucoma. This means that the manufacturers of these medications have not applied for a licence for their medication to be used to treat glaucoma.
But many specialists will use an unlicensed medication if they think the medication is likely to be effective and benefits of treatment outweigh associated risk. The National Institute for Health and Care Excellence (NICE) has issued guidance for the treatment of chronic open-angle glaucoma. It suggests these medicines can be used.
Acute angle-closure glaucoma
As acute glaucoma develops rapidly, the condition needs to be treated quickly. The most common forms of treatment for this type of glaucoma include:
- eye drops – see above for further details
- systemic medicines – these are injected into your bloodstream to quickly reduce the pressure in your eye
- laser treatment (called laser iridotomy) – this uses high-energy beams of light to create holes in your iris (coloured part of the eye) to open the angle and enable fluid to flow; both eyes may need to be treated, even if only one has acute angle-closure glaucoma, because this form of glaucoma may develop in both eyes at some point
- surgery – a trabeculectomy (surgery to remove part of the drainage tubes) is the most common form of surgery for acute glaucoma
If you also have a cataract (a cloudy patch in the lens of your eye), removing it may open the angle in your eye and control the intraocular pressure.
Acute angle-closure glaucoma may also be treated with a medication called a miotic, such as pilocarpine.
Miotics work by opening up the blocked trabecular meshwork, which should improve the drainage of aqueous humour out of your eye. You may need to use these eye drops up to four times a day.
Miotics should be used with caution in people who have certain medical conditions, including:
Miotics can also cause side effects, such as:
- a headache, which may be severe during the first two to four weeks of treatment
- burning or itchy eyes
- blurred vision, which may affect your ability to drive
Treating other types of glaucoma
For other types of glaucoma, your specialist will usually recommend eye drops, laser treatment or surgery. Your treatment will depend on the type of glaucoma you have and how advanced it is.
Monitoring your condition
If you have been diagnosed with glaucoma your condition will be closely monitored to check for further damage to your vision.
Depending on how your glaucoma is progressing, you may need further appointments every one to four months or up to 12-24 months apart.
6. Micro-invasive Glaucoma surgery (MIGS)
The Xen is a soft, collagen-based gelatin implant. Because it is injected into the subconjunctival space via an ab interno route through a clear corneal incision the technology is categorized as microinvasive glaucoma surgery (MIGS). The Xen is the only MIGS procedure, however, that uses a space typically accessed in an ab externo fashion with the goal of an external, subconjunctival fistula. It is therefore an interesting and unique “hybrid” that could conceivably be performed as a primary procedure in the early stages of glaucoma without eliminating the option of standard filtration surgery in the future.
Nor would the device preclude future treatment with ab interno MIGS procedures such as the iStent Trabecular Micro-Bypass Stent (Glaukos), CyPass Micro-Stent (Transcend Medical), Trabectome (NeoMedix), or Hydrus (Ivantis). Future endoscopic cyclophotocoagulation would also be an option.
Additional advantages of the Xen compared with glaucoma surgeries that filter to a subconjunctival space are the absence of any incision in the conjunctiva and the minimal ab interno dissection that occurs.
Currently, the implant is under investigation and a prospective, multicenter clinical trial is underway. Early results from Europe, Canada, and South America demonstrate an IOP in the midteens after up to 2 years of follow-up. Data were presented at the World Glaucoma Congress and at the American Society of Cataract and Refractive Surgery annual symposium last year. At 1 year, the average IOP was 15.3 mm Hg with a mean medication use of 1.0. Of the patients who completed 1 year of follow-up, 66% achieved an IOP less than or equal to 16 mm Hg and/or a 30% drop in IOP.5