6 Questions to Ask Before Starting Glaucoma Treatment
Glaucoma and eye pressure
Glaucoma occurs when pressure in your eye damages the nerve that connects it to the brain. This nerve is called the optic nerve. Damage to this nerve can result in reduced vision. Like an over-inflated soccer ball, an eye with high pressure is very firm; this firmness is due to high pressure in the eye. High pressure occurs when fluid made within the eye is obstructed from draining out of the eye.
The optic nerve at the back of the eye connects the eye to the brain; without it, the brain cannot register what the eye is seeing. This nerve is quite sensitive to raised pressure that can damage it. The damage is slow and usually painless, but progressive and irreversible; any damage to the optic nerve cannot be repaired.
Glaucoma cannot be cured, but it can be effectively managed overtime. Control of eye pressure, either through daily eye drops, gentle laser or glaucoma surgery, can halt the progress of glaucoma and preserve one’s vision for life. Early detection and meticulous monitoring of the optic nerve over time are the keys to good management of glaucoma.
1. Do I really need my eye pressure lowered?
Many people have raised eye pressure that is not yet doing any damage to the optic nerve; i.e. they do not have glaucoma, just raised eye pressures that might one day lead to glaucoma.
For some people, especially in the absence of other risk factors for glaucoma, it is okay not to lower the eye pressure, provided their optic nerves are appropriately monitored for change over time.
2. Do I have glaucoma or another optic nerve disorder?
Other conditions that may affect the optic nerve can look like glaucoma, and produce test results that resemble glaucoma, but do not need eye pressure lowering. It is important to consider alternate diagnoses first.
3. Do I have open or narrow drainage angles?
There are two main types of glaucoma – open angle glaucoma, and narrow angle glaucoma. Both result in reduced drainage of fluid from within the eye and cause raised eye pressure and glaucoma.
In open angle glaucoma, the fluid can reach the eye’s drainage area but has difficulty escaping through damaged drainage channels. In narrow angle glaucoma, the fluid cannot even reach the drainage area, as the narrow angle blocks the access.
Narrow angle: The fluid is blocked from reaching the drainage area.
Open angle and narrow angle glaucomas require completely different treatment approaches. In open angle glaucoma, it is important to reduce the eye pressure using drops, gentle SLT laser or surgery. In narrow angle glaucoma, the first step is always to open the angle, either with iridotomy laser or sometimes cataract surgery.
To learn more about the effects of narrow and open angle glaucoma, head to our resource page on narrow angles and laser peripheral iridotomy.
4. What is SLT laser? Can I use it instead of daily drops?
SLT (Selective Laser Trabeculoplasty) is a gentle form of laser therapy in which the drainage area of the eye is stimulated by light energy to drain more fluid. The laser is too brief and gentle to damage the eye – it works by stimulating cells whose job it is to clear the drainage pathways at a microscopic level.
These cells can get lazy over time, causing the drainage pathways to clog up (think of leaves rotting in a gutter); the laser gets the cells to clear the paths and thereby lowers eye pressure.
SLT laser: Brief pulses of gentle light energy are shone onto the eye’s drainage angle to restoring its previous function; by draining more fluid the eye pressure lowers.
SLT is very safe, effective in the majority of cases, and works like an eye drop – except you don’t have to remember to use the drop, and you don’t get the irritating side effects of the drops. The SLT effect may wear off over time (3-4 years on average) but is repeatable.
SLT laser, while not new (it has been around for 25 years), is being used with more confidence and good effect to treat glaucoma or raised eye pressure. In fact, some very strong evidence from the UK has recently emerged showing that SLT is as effective, and in some ways superior, to glaucoma eye drops.1
Certainly, over the long term, the common long-term problems associated with drops (changes to the appearance of the eyes, irritated, gritty eyes, or forgetting to instil the drops) are not a problem with the SLT laser.
Talk to your eye doctor about the alternative options of glaucoma drops or SLT laser to lower eye pressure.
1. Selective laser trabeculoplasty versus eye drops for first-line treatment of ocular hypertension and glaucoma (LiGHT): a multicentre randomised controlled trial. Gazzard G, Konstantakopoulou E, Garway-Heath D, et al; LiGHT Trial Study Group. Lancet. 2019 Apr 13;393(10180):1505-1516.
5. What are the risks of this treatment?
Every treatment in medicine has risks – sometimes the risks are small, and generally, the risks are outweighed by the benefits of the treatment (hopefully that’s why the treatment is being suggested to you).
However, all eye drops have side effects, and many kinds of laser can cause transient problems with eye discomfort or temporary eye pressure rises. When making decisions about different treatments, make sure you understand the potential risks, and weigh these against the potential benefit of the treatment.
6. Will this treatment definitely work?
Success is not guaranteed with any form of glaucoma treatment, whether drops, laser or surgery. It is important to realise this from the outset, and know the chances of success as well as the potential risks of treatment. You may wish to ask your doctor – what will we do if this treatment doesn’t work?