Glaucoma is a common eye condition that can slowly damage the optic nerve — the “cable” that connects your eye to your brain. This usually happens when the pressure inside the eye, known as intraocular pressure, becomes too high. If left untreated, it can lead to loss of vision.
The good news is that glaucoma can almost always be managed successfully with early diagnosis and the right treatment. For many years, the usual first treatment was daily eye drops to lower pressure. But now, a simple laser treatment called Selective Laser Trabeculoplasty, or SLT, is now the preferred first option for many people.
A Simpler Way to Control Eye Pressure
SLT is a quick, gentle laser treatment that helps the eye’s natural drainage system work better. It doesn’t involve any cuts or needles and usually takes just ten minutes per eye in a clinic. You can go home straight afterwards, and most people are back to normal the next day.
The treatment uses short pulses of light to target the drainage channels in the eye, helping fluid flow out more easily and lowering the pressure. It doesn’t burn or remove tissue — instead, it stimulates the eye to clean and repair its own drainage system.
For many patients, the biggest advantage is that SLT can control pressure without the need for daily drops. Eye drops work well, but they can cause irritation, be difficult to remember every day, and some people find them uncomfortable or inconvenient.
The Evidence Behind SLT
A major UK research project called the LiGHT study (Laser in Glaucoma and Ocular Hypertension Trial) compared people who started treatment with SLT to those who began with eye drops.
The results were remarkable. Around three out of four people who had SLT as their first treatment did not need any drops for at least three years afterwards. Their eye pressure stayed well controlled, they experienced fewer side effects, and they were less likely to need surgery later on.
Over six years of follow-up, SLT continued to perform well. People who started with laser had better long-term control of their disease and fewer additional treatments. It was also more cost-effective for the NHS over time because it reduced the need for long-term medications.
New National Guidance
The results of the LiGHT study were so strong that they led to an important change in national guidance. The National Institute for Health and Care Excellence (NICE) now recommends that SLT should be offered as the first treatment for most people with open-angle glaucoma or ocular hypertension — the most common types of the condition.
This means that when someone is newly diagnosed, their eye specialist will usually suggest starting with SLT rather than eye drops. Of course, some patients may still choose drops or need them later, but the evidence shows that SLT is a safe and effective first step for many.
What to Expect from SLT
If you choose to have SLT, you’ll have numbing drops put into your eye so the treatment is comfortable. A small lens is placed gently on the eye to help focus the laser, and the specialist will apply short bursts of light to the drainage area. You might see some flashes, but it isn’t painful.
Afterwards, your vision may be a little blurry for a few hours and your eye might feel slightly gritty for a day, but most people recover very quickly.
SLT has an excellent safety record. Occasionally, the pressure can rise temporarily, or the eye may be slightly red for a day or two, but serious complications are extremely rare.
A Brighter Outlook for Glaucoma Care
For many years, laser treatment was only offered after eye drops stopped working. Thanks to the LiGHT study and the new NICE guidance, that has changed. Today, patients can benefit from SLT right from the start — avoiding or delaying the need for daily drops and improving long-term outcomes.
If you’ve recently been diagnosed with glaucoma or high eye pressure, it’s worth asking your eye specialist whether SLT might be right for you. It’s a simple, safe, and effective treatment that can help protect your sight — and make life a little easier.
Dr Andrew Tatham is a Consultant Ophthalmologist and Glaucoma Specialist, and President of the UK & Eire Glaucoma Society (UKEGS). He is passionate about improving glaucoma care and raising awareness of new, patient-friendly treatments like SLT.
