Glaucoma is a group of conditions where the optic nerve in the eye becomes damaged over time. If undiagnosed it can lead to permanent blindness.
A person with glaucoma does not notice anything unusual in the early stages of the condition as it affects the outside of the vision first. By the time the person notices a problem with their vision it is often too late. It is important that everyone has their eye pressures tested every two years and annually if there is a family history of glaucoma.
It is important that the condition is discovered early as prompt treatment is very effective in preventing damage and blindness.
There are different types of glaucoma. The eye pressure may be high in a glaucoma patient but not always. The eye pressure is not related to blood pressure or stress. The only treatment for glaucoma is to lower the eye pressure even if it is within the normal range at diagnosis.
How much should we lower the IOP?
We aim to reduce the IOP by 20-30% initially. Research shows that reducing the IOP by 20% reduces glaucoma progression by 50%. Every glaucoma patient will have a personalised ‘target IOP’ set and it will depend on how high the IOP is at diagnosis.
How can the intraocular pressure (IOP) be lowered?
The IOP can be lowered with drops, laser or with surgery.
When drops are prescribed they should be used forever. Unlike antibiotics, it is not a course of treatment.
There are 4 main groups of glaucoma eye drops.
1. Prostaglandin analogues- latanoprost, travoprost, bimatoprost & tafluoprost
These are used once daily at night. They are the most effective of all glaucoma drops. They have few side effects and are well tolerated. They make the eyelashes grow longer and thicker and can cause some colour change in the iris or the skin around the eye.
These drops are used twice daily and were the gold standard drops until the PGAs were discovered in 2001. They are effective and are usually second line. If you need more than a PGA to control the IOP it is usual to co-prescribe the PGA and Beta-blocker in a single bottle. This makes it easier and more convenient for you to take your treatment. This is used twice daily. Patients with asthma or very slow heart rates cannot usually have beta-blockers and it is important that you tell us if you have these conditions at your consultation
Iopidine is used at the time of glaucoma laser treatments as it works very quickly but the effect does not last very long. Brimonidine lasts much longer as is used commonly as the third line drop in glaucoma. It is effective but can make the eye quite red even after some months of use with some patients developing an allergy to it. In these cases the drop is stopped and the redness resolves.
4. Carbonic anhydrase inhibitors
Dorzolamide and Brinzolamide are used 2-3 times daily and are commonly prescribed in combination with beta-blockers in a single bottle.
If you have any questions about your drops or the schedule for taking them please ask as it can be confusing when you start drops or if they are changed.
My drops really sting when I put them in and they make my eyes red, what shall I do?
It is common for newly prescribed glaucoma drops cause some redness at first. It is unusual to be allergic to the drug in the bottle of drops within the first 2 weeks. The redness is usually mild and settles after the first 2 weeks of treatment so continue with them for at least 2 weeks if you feel able to. If the redness and discomfort persist beyond the first month it is likely that your eyes are sensitive to the preservative in the eye drop bottle that keeps the bottle free from bacteria. It may be that a preservative free glaucoma drop is better for you. Preservative free (PF) preparations are now available for most glaucoma drops and our consultants can recommend a suitable one for you.
How do I get a new bottle of drops?
It is important that you order replacement bottles in good time from your GP. The drops quickly wear off if not used daily allowing the IOP to rise to a potentially damaging level once more.
If your glaucoma drops are causing you problems please let your specialist know so that a suitable alternative can be found. Do not go without the glaucoma drops. It is usually possible to find one that is both effective and comfortable to use.
Laser treatment can be as effective as drops in lowering the IOP. It is a good alternative to drops in some patients.
Selective laser trabeculoplasty (SLT) is a laser treatment that can reduce the IOP by 20-30%, as much as an eye drop in patients who respond well to the treatment. This can mean that laser alone will be sufficient to control the IOP without the need for daily drops for 3-5 years. SLT is painless and can be done in the clinic. The laser modifies the normal physiological drainage pathway within the eyeball and encourages it to drain the aqueous fluid more effectively. It does not damage the eye and is a very safe & well-tolerated treatment. It is especially suitable for patients who cannot put drops in or who cannot tolerate some of the side effects of glaucoma drops.
Some glaucoma patients will need surgical treatment for their glaucoma. This is especially the case in patients who present with advanced damage at diagnosis or in those for whom drops and laser are not sufficient to lower the IOP.
Surgical treatments include trabeculectomy, glaucoma drainage devices or ‘Phaco +’ procedures where cataract surgery is undertaken along with a glaucoma micro stent or laser treatment inside the eye.
Trabeculectomy surgery is the commonest glaucoma operation performed worldwide. A new pathway for fluid to drain away from the eye is created using the patients’ own tissue. A glaucoma drainage device is used in complex cases where a small silicone tube attached to a drainage plate is inserted into the front chamber of the eye allowing fluid to drain away via this implant.