Dr Francisco J. Abellán
Glaucoma: fewer drops with SLT laser and MIGS in Madrid
SLT laser and MIGS surgery can control glaucoma with fewer drops, sparing the surface of the eye.
Ophthalmologist · Medical registration no. 282880215
Trained at Hospital Universitario de La Princesa
The practice secretary manages information and private appointments.
Why does the pressure need to come down?
Glaucoma damage does not recover. Lowering the pressure, with drops, laser or surgery, aims to slow visual-field loss.
Just diagnosed, or not on treatment yet? Start with the guide to understanding glaucomaScroll down or tap a stage to see how the visual field changes.
Full field. The optic nerve is healthy and the visual field is complete.
Early loss. An arc of reduced sensitivity appears above the centre. The other eye and the brain fill the gap, so it usually goes unnoticed.
Moderate damage. The defect becomes denser and a second one appears below. It may show when going down stairs or driving, yet many people still do not notice it.
Advanced damage. Little more than an island of central vision remains. Lost vision does not come back: treatment aims to slow progression.
Illustrative simulation: it does not predict how any individual case will progress.
Controlling glaucoma with fewer drops
Drops work, but years of them take a toll on the eye. SLT laser and surgery lower the pressure without relying on them as much.
What drops do to the eye over the years
- Dry eyeThe preservatives in many drops damage the tear film.
- Red, irritated eyeChronic inflammation of the eye’s surface.
- Eyelid changesA sunken upper lid and darker skin with prostaglandins.
- AllergiesItching and swollen lids with some drops.
Sources: Systematic review, Bioengineering 2024 · Turk J Ophthalmol 2023
What the studies show
Eyes that progressed (LiGHT trial, 6 years, newly diagnosed patients)
- SLT first19.6 %
- Drops first26.8 %
7 out of 10
eyes that started with SLT laser were still at their target pressure without drops or surgery after 6 years, sometimes after repeat laser (LiGHT trial, 6 years).
Needed glaucoma surgery (trabeculectomy): 13 eyes that started with SLT versus 32 that started with drops (LiGHT trial, 6 years).
In advanced glaucoma, trabeculectomy achieved lower pressures than drops (12.4 versus 15.1 mmHg) with fewer medications (TAGS trial, 2 years); its long-term effect on progression is still being studied.
Results from clinical trials in groups of patients: in each eye, the result may differ.
Sources: LiGHT trial, Ophthalmology 2023 · LiGHT, Ophthalmology 2025 · TAGS trial, Health Technol Assess 2021
Will I be able to stop my drops completely?
It depends on each eye. In the LiGHT trial, in newly diagnosed patients, 7 out of 10 eyes that started with SLT laser still needed no drops or surgery after 6 years; if you already use drops, SLT or MIGS can allow fewer medications. It cannot be guaranteed, and even if drops are stopped, follow-up with tests continues.
Source: LiGHT trial, Ophthalmology 2023
What if my drops disagree with me or I forget them?
If you forget a drop, use it when you remember unless the next one is nearly due; do not double the dose. If you notice persistent stinging, a red eye or other effects, mention it: there are often alternatives, including SLT laser or MIGS. Do not stop treatment without discussing it.
How do SLT laser and MIGS work?
Both act on the eye’s natural drain, the drainage angle. Tap an option: you will see the change in a sink and where it happens in the eye.
The options at a glance
Pressure: High
The drain gets clogged. The trabecular meshwork filters poorly: fluid struggles to leave and pressure rises without symptoms.
Drops make up for it every day. They reduce fluid production or help it drain. They work as long as they are used every day, on time.
The laser improves the filter. Low-energy pulses on the meshwork, in the clinic and without incisions, help fluid drain better again.
A micro-implant opens a path. A tiny implant crosses the meshwork and connects the chamber with Schlemm’s canal. It is often placed during cataract surgery.
A tube creates a new outlet. A very fine tube, such as the XEN implant, carries fluid under the conjunctiva, where it forms a small bleb from which it is absorbed.
In the eye, the tap is behind the iris and the drain is the trabecular meshwork
The eye seen from the side, looking left. The box marks the front of the eye, from the pupil to the corner where the cornea meets the iris: that is where the drain is. Below, that area enlarged, with the outside of the eye at the top and the pupil on the left.
Simplified diagram for information purposes.
View the full 3D journeyDo laser or surgery cure glaucoma?
No. They do not restore damage already done or remove the need for check-ups. Their aim is to lower pressure to slow progression, with less dependence on drops.
Read the glaucoma surgery guideWhat is target pressure?
It is the pressure below which damage is expected not to progress, or to progress very slowly. It is set for each eye according to existing damage, starting pressure, age and other factors, and it is reviewed if tests show change.
SLT or MIGS: what changes?
Two different paths to the same goal: lowering pressure with fewer drops.
- Where
- SLT laser: In the clinic
- MIGS surgery: In theatre, no hospital stay
- Anaesthesia
- SLT laser: Anaesthetic drops
- MIGS surgery: Local anaesthesia
- Duration
- SLT laser: A few minutes
- MIGS surgery: A short procedure
- Recovery
- SLT laser: Normal life the same or next day
- MIGS surgery: A few days with drops and simple care
- Can it be repeated?
- SLT laser: Yes, if the effect wears off
- MIGS surgery: Sometimes needs adjustments or added treatment
- With cataract surgery?
- SLT laser: Done separately
- MIGS surgery: Yes, it can be done in the same operation
- And the drops?
- SLT laser: Can be reduced or stopped for a time
- MIGS surgery: Can be reduced or stopped; depends on the technique
How long does SLT last and can it be repeated?
The effect usually appears within a few weeks and can last years, although it tends to wear off over time and varies between people. If it wears off, SLT can be repeated in selected cases or combined with drops.
Can MIGS be done at the same time as cataract surgery?
Yes. Many MIGS techniques are done in the same operation as cataract surgery, through the same incision; others can be done separately. The choice depends on the type of glaucoma, the target pressure and the state of the lens.
Am I a candidate?
Usually considered if…
- Open-angle glaucoma at a mild or moderate stage, or ocular hypertension.
- Your drops disagree with you, are hard to put in or get forgotten.
- You need two or more drops to control the pressure.
- You have a cataract due for surgery: MIGS can be done in the same operation.
Another option is considered if…
- Advanced damage or very high pressure: filtering surgery, such as trabeculectomy, may be needed.
- Narrow angle: treatment usually starts with laser iridotomy or lens surgery.
Does high eye pressure mean I have glaucoma?
No. High pressure increases risk, but diagnosis requires assessment of the optic nerve, visual function, angle and change over time. Glaucoma can also occur at statistically normal pressures.
Can I ask for an assessment if another ophthalmologist treats me?
Yes. Bring your reports, visual fields, OCT scans and list of drops, so your progression, and whether SLT or MIGS make sense for you, can be assessed.
How to prepare for your appointmentWhat is treatment day like?
SLT laser
In the clinic
- 1
BeforeAnaesthetic drops and sometimes a drop to prevent a pressure spike.
- 2
DuringA lens on the eye and laser pulses on the meshwork for a few minutes.
- 3
AfterYou go home the same day; the eye may feel slightly irritated for a few hours.
- 4
Check-upPressure is measured in the following weeks and drops are adjusted.
MIGS surgery
In theatre, no hospital stay
- 1
BeforeAssessment and tests; if you have a cataract, it is planned in the same operation.
- 2
DuringLocal anaesthesia and a short procedure.
- 3
AfterPost-operative drops for a few weeks and simple care at home.
- 4
Check-upsClose check-ups at first to adjust pressure and treatment.
Does SLT laser hurt?
Usually not. It is done with anaesthetic drops and a lens on the eye; you see flashes of light and sometimes feel mild discomfort. Afterwards the eye may feel irritated or vision may be blurred for a few hours.
What are the risks of MIGS surgery?
Like any surgery, it has risks. With subconjunctival techniques the bleb often needs adjustments at check-ups, sometimes with a small in-clinic procedure. The pressure may not come down enough, so drops or another treatment may still be needed. Serious complications, such as infection or persistently low pressure, are uncommon. They are explained at the assessment for each technique.
Preparing for glaucoma surgeryWhen can I drive or go back to work?
After SLT, usually the next day or once vision is clear; many people work the same day. After MIGS it depends on your vision and your job: usually a matter of days, confirmed at the first check-up.
Care after glaucoma surgeryHow much does it cost and will my insurance cover it?
Many health insurers cover SLT laser and glaucoma surgery, depending on the policy. And if you have no insurance, don’t worry: after the assessment we give you a quote tailored to you.
The treatment
Recommended treatment
SLT, MIGS or MIGS with cataract surgery, depending on the assessment.
Cover
With health insurance
Many insurers cover laser and surgery; some techniques need prior authorisation. The secretary checks your policy before scheduling.
- or
No medical insurance
Don’t worry. After the assessment we give you a clear quote, tailored to you.
The budget
Final budget
With insurance, according to your policy. Without insurance, a tailored quote after the assessment.
Does my insurance cover laser and surgery?
Many health insurers cover SLT laser and glaucoma surgery, but it depends on each policy and some techniques need prior authorisation. The secretary checks your cover before scheduling. Without insurance, you receive a quote after the assessment.
Private consultation at Centro de Especialidades Clara del Rey, Hospital Quirónsalud San José.
Check my insurance or request a quoteWhy consult Dr Abellán?
SLT and MIGS in one practice. Laser in the clinic and surgery in theatre with the same specialist.
Decisions based on progression. Your tests are compared over time before anything is changed.
Clinical training and experience. Training at La Princesa, with public and private clinical practice.
Continuity of care. The same specialist reviews your tests and follows you over time.
Reviews on Google
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Frequently asked questions about SLT and MIGS
Each question links to its answer on this page.
- Will I be able to stop my drops completely?
- What if my drops disagree with me or I forget them?
- Do laser or surgery cure glaucoma?
- What is target pressure?
- How long does SLT last and can it be repeated?
- Can MIGS be done at the same time as cataract surgery?
- Does high eye pressure mean I have glaucoma?
- Can I ask for an assessment if another ophthalmologist treats me?
- Does SLT laser hurt?
- What are the risks of MIGS surgery?
- When can I drive or go back to work?
- Does my insurance cover laser and surgery?
Request a glaucoma assessment in Madrid
The practice secretary can explain the private pathway, check your insurance and book an assessment to see whether SLT or MIGS suit you.
Bring your reports, previous visual fields and OCT scans, and the list of drops with their schedule.
The practice secretary manages information, insurers, administrative procedures and private appointments. This is not a medical-advice or emergency channel: do not send clinical reports, and use the emergency service or the channel indicated by your healthcare centre for urgent symptoms.
Authorship, medical review and sources
- Author and medical reviewer
- Dr. Francisco Javier Abellán Martínez
- Ophthalmologist · Medical registration no. 282880215
- The same specialist currently authors and medically reviews the content; this is not presented as an independent external review.
- Last medically reviewed
Sources consulted (3)
- Terminology and Guidelines for Glaucoma, 6th edition (Opens in a new tab)European Glaucoma Society
- Glaucoma: diagnosis and management (NG81) (Opens in a new tab)National Institute for Health and Care Excellence (NICE)
- Patient information booklets (Opens in a new tab)The Royal College of Ophthalmologists
General educational content. It does not replace an individual assessment, diagnosis or personalised instructions from your healthcare team.
How these guides are written and reviewed